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STUDIES ON THE PREPARATION OF PEANUT MILK
AND MILK POWDER
M.Tech. (Agril. Engg.) Thesis
by
Perugu Balachandra Yadav
DEPARTMENT OF AGRICULTURAL PROCESSING AND FOOD ENGINEERING
FACULTY OF AGRICULTURAL ENGINEERING INDIRA GANDHI KRISHI VISHWAVIDYALAYA
RAIPUR (Chhattisgarh) 2016
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STUDIES ON THE PREPARATION OF PEANUT MILK
AND MILK POWDER
Thesis
Submitted to the
Indira Gandhi Krishi Vishwavidyalaya, Raipur
by
Perugu Balachandra Yadav
IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF
Master of Technology
in
Agricultural Engineering
(AGRICULTURAL PROCESSING AND FOOD ENGINEERING)
Roll No: 20141520462 ID No: 220114004
JULY, 2016
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ACKNOWLEDGEMENT
I start with the name of “God” who is the most beneficial and merciful; I
offer him uncountable thanks, without whose blessings and mercy; this work would
have not been a success. Research is an evolving concept. Any endeavour in this
regard is challenging as well as exhilarating. It brings to light our patience, vigour
and dedication.
I feel great pleasure in expressing my sincere and deep sense of gratitude
towards Chairman of my Advisory Committee Dr S. Patel, Professor & Head of
the Department, Department of Agricultural Processing and Food Engineering,
Faculty of Agricultural Engineering, IGKV, Raipur, for his valuable guidance,
constant inspirations and moral support throughout the research work.
It is beyond my means and capacity to put in words my sincere gratitude to
my Co-Chairman Dr. D. Bhaskara Rao, Dean of Agricultural Engineering &
Technology, Acharya N. G Ranga Agricutural University (ANGRAU), Lamfarm
Guntur, Andhra Pradesh, for his continuous advice, guidance and encouragement
throughout the course of investigations. I am also indebted to Dr. Sivala Kumar,
Professor and Head, Department of Agril. Processing and Food Engineering,
College of Agricultural Engineering (ANGRAU), Baptala (AP) for accepting me
for the present research and providing all facilities and support during my stay at
Bapatla (AP).
I am deeply obliged to Dr. L. Edukondalu, Asstt. Professsor, Department of
Agril. Processing and Food Engg., College of Agricultural Engineering
(ANGRAU), Bapatla for extending necessary facilities and endless cooperation
during the entire duration of thesis. My sincere thanks are also due to Shri S.
Visnuvardhan, Scientist, AICRP on PHTC, Bapatla (AP). I am very thankful to
members of my advisory committee Dr. R. R. Saxena, Professor (Agril. Statistics)
and Asociate Director Research, Dr. R. K. Naik, Scientist (AICRP on FIM) and Dr.
D. Khokhar, Scientist (AICRP on PHET) for encouragement, support and help
rendered during my study period. I also place on record the help and support
received from Er. P. S. Pisalkar (Asstt.Prof.) and Er. N.K. Mishra (Scientist,
AICRP on PHET) at every stage during my study period at IGKV, Raipur.
My literacy power is too less to express my gratitude to Hon’ble Vice
Chancellor Dr. S. K. Patil, and Director Research Services, IGKV, Raipur. I am
very much thankful to Dr. S. S. Shaw, Director Instructions, I.G.K.V., Raipur for
providing necessary facilities and conducting promptly research & examination
related to the project. I am also very much thankful to Dean Dr. V.K. Pandey,
Faculty of Agricultural Engineering, I.G.K.V., Raipur for their guidance and
providing necessary inputs. I also like to express my sincere thanks to Head of
Department of Soil and Water Engineering and Head of Department of Farm
Machinery and Power for their kind support and help at various stages of the
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study. I am also thankful to Dr. B V S Prasad, Associate Dean, College of Food
Science & Technology Bapatla, ANGRAU for kind support and encouragement.
I avail this pleasant opportunity to express my sincere thanks to all of my
friends, Nagendram, Ramu, Shobhan, Jr Saritha, Deepika madam, and all other
friends whom remembrances remain in my heart for their love, contribution and
timely help during course of study. I also express my special thanks to all those
who helped directly or indirectly during this study.
I owe and extend my respect, love to my parents, Father Perugu Veeraiah,
Mother Perugu Obulamma, Brothers & Sisters for their constant love, affection,
motivation, encouragement and sincere prayers, so as to enable me to complete
this task.
I would like to convey my cordial thank to all those who helped me directly
or indirectly to fulfill my dreams come true.
Date: 29/06/2016
Place: Raipur (Perugu BalachandraYadav)
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TABLE OF CONTENTS
Chapter Title Page
No
ACKNOWLEDGEMENT
LIST OF TABLES
LIST OF FIGURES
LIST OF PLATES
LIST OF ABBREVIATIONS
LIST OF SYMBOLS
ABSTRACT
I INTRODUCTION 1-4
1.1 General 1
1.2 Peanut production in the world 1
1.3 Peanut production in the India 2
1.4 Nutritional composition of peanuts 2
1.5 Uses of peanuts 3
1.6 Peanut milk 3
1.7 Peanut milk powder 4
II REVIEW OF LITERATURE 5-26
2.1 Nutritional composition of peanuts 5
2.2 Nutritional composition of peanut milk 8
2.3 Preparation on Peanut milk based products 12
2.4 Spray drying behavior on different quality products 19
2.5 Development and characterization of peanut milk
powder for use in chocolate manufacture
25
III MATERIALS AND METHODS 27-47
3.1 Procurement of raw materials 27
3.2 Technical programme of work 27
3.2.1 Dependent parameters
3.2.2 Independent parameters
3.3 Preparation of peanut milk 28
3.4 Traditional method 28
3.4.1 Normal soaking
3.4.2 Soaking in 1% NaHCO3
3.4.3 Roasting
3.4.4 Pressure blanching
3.5 Preparation of Peanut milk powder using spray dryer 29
3.5.1 Technical specification of Tall-type spraydrier
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3.5.2 Spray Drying Chamber
3.5.3 Atomization
3.5.4 Spray–Air Contacts
3.5.5 Moisture Evaporation
3.5.6 Separation of Dried Products
3.5.7 Feed pump
3.5.8 Nozzle
3.5.9 Pressure nozzle atomizer
3.5.10 Powder recovery
3.6 Proximate analysis of peanut milk and milk powder 35
3.6.1 Estimation of moisture content in milk and
milk powder
35
3.6.1.1 Calculation
3.6.2 Estimation of Protein content on milk by
pyne’s method (Formal titration)
35
3.6.2.1 Principle
3.6.2.2 Apparatus
3.6.2.3 Reagents
3.6.2.4 Procedure
3.6.2.5 Calculation
3.6.3 Estimation of Protein content in milk powder
by using kjeldhal method
37
3.6.3.1 Materials
3.6.3.2 Procedure
3.6.3.3 Calculation
3.6.4 Estimation of fat content of milk by Rose
Gottleib method
39
3.6.4.1 Principle
3.6.4.2 Apparatus
3.6.4.3 Reagents
3.6.4.4 Procedure
3.6.4.5 Calculation
3.6.5 Estimation of fat content of milk powder by
Soxhlet apparatus method
40
3.6.6 Estimation of ash content 42
3.6.6.1 Procedure
3.6.6.2 Calculation
3.6.7 Estimation of crude fiber content in milk
powder
43
3.6.7.1 Materials
3.6.7.2 Procedure
3.6.7.3 Calculation
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3.6.8 Estimation of total solids (Gravimetric
method)
44
3.6.8.1 Principle
3.6.8.2 Apparatus
3.6.8.3 Preparation of sample
3.6.8.4 Procedure
3.6.8.5 Calculation
3.6.9 Estimation of carbohydrate content in milk
and milk powder
45
3.6.9.1 Principle
3.6.9.2 Materials
3.6.9.3 Procedure
3.6.9.4 Calculation
3.6.10 Estimation of pH in milk 47
3.6.10.1 Apparatus
3.6.10.2 Procedure
3.6.11 Estimation of pH in milk powder 47
IV RESULTS AND DISCUSSION 48-78
4.1 Proximate Analysis of peanut milk based on different
methods of preparation
48
4.2 Proximate Composition of peanuts 48
4.3 Proximate Analysis of peanut milk based on
traditional methods
49
4.3.1 Normal soaking
4.3.2 Soaking in Sodium Bicarbonate
4.3.3 Roasting
4.3.4 Pressure blanching
4.3.4.1 Pressure blanching for 0 minutes
4.3.4.2 Pressure blanching for 2 minutes
4.3.4.3 Pressure blanching for 3 minutes
4.3.4.4 Pressure blanching for 5 minutes
4.4 Comparison of the proximate composition of peanut
milk prepared by different methods
54
4.4.1 Moisture content
4.4.2 Protein Content
4.4.3 Fat Content
4.4.4 Carbohydrates content
4.4.5 Ash Content
4.4.6 pH Value
4.4.7 Total Solids
4.5 Preparation of peanut milk powder using spray dryer 59
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technique methods of preparation
4.6 Proximate Analysis of peanut milk powder based on
different
59
4.7 Proximate Analysis of peanut milk powder based on
traditional methods
59
4.7.1 Normal soaking
4.7.2 Soaking in Sodium Bicarbonate
4.7.3 Roasting
4.7.4 Pressure blanching
4.7.4.1 Pressure blanching for 0 minutes
4.7.4.2 Pressure blanching for 2 minutes
4.7.4.3 Pressure blanching for 3 minutes
4.7.4.4 Pressure blanching for 5 minutes
4.8 Comparison of the proximate composition of peanut
milk powder by different methods
64
4.8.1 Moisture content
4.8.2 Protein Content
4.8.3 Fat Content
4.8.4 Carbohydrate Content
4.8.5 Crude fiber Content
4.8.6 Ash Content
4.8.7 Total Solids
4.8.8 pH Value
4.9 Comparison between peanut milk and milk powder 70
4.9.1 Normal soaking
4.9.2 Soaking in sodium bicarbonate
4.9.3 Roasting
4.9.4 Pressure blanching
4.9.4.1 Pressure blanching for 0 minutes
4.9.4.2 Pressure blanching for 2 minutes
4.9.4.3 Pressure blanching for 3 minutes
4.9.4.4 Pressure blanching for 5 minutes
V SUMMARY AND CONCLUSIONS 79-81
REFERENCES 82-89
APPENDICES
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LIST OF TABLES
Table Caption Page No. 1.1 Production of peanuts in the world 1 1.2 Production of peanuts in the India 2 1.3 Nutritional compositions of peanuts 3
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LIST OF FIGURES
Figure Caption Page No.
4.1 Proximate composition of raw peanuts 49 4.2 Proximate composition of peanut milk (Normal soaking) 49 4.3 Proximate composition of peanut milk (Soaking in 1%
NaHCO3) 50
4.4 Proximate composition of peanut milk (Roasted peanuts) 51 4.5 Proximate composition of peanut milk (Pressure blanching
for zero minutes) 51
4.6 Proximate composition of peanut milk (Pressure blanching for 2 minutes)
52
4.7 Proximate composition of peanut milk (Pressure blanching for 3 minutes)
53
4.8 Proximate composition of peanut milk (Pressure blanching for 5 minutes)
53
4.9 Moisture contents of peanut milk prepared in different conditions
54
4.10 Protein contents of peanut milk prepared by different methods
55
4.11 Fat contents of peanut milk prepared by different methods 56 4.12 Carbohydrate contents of peanut milk prepared by different
methods 56
4.13 Ash contents of peanut milk prepared by different methods 57 4.14 pH contents of peanut milk prepared by different methods 58 4.15 Total solids of peanut milk prepared by different methods 58 4.16 Proximate composition of peanut milk powder (Normal
soaking) 60
4.17 Proximate composition of peanut milk powder (Soaking in 1% NaHCO3)
60
4.18 Proximate composition of peanut milk powder (Roasting) 61 4.19 Proximate composition of peanut milk powder (Pressure
blanching for zero minutes) 62
4.20 Proximate composition of peanut milk powder (Pressure blanching for 2 minutes)
62
4.21 Proximate composition of peanut milk powder (Pressure blanching for 3 minutes)
63
4.22 Proximate composition of peanut milk powder (Pressure blanching for 5 minutes)
64
4.23 Moisture contents of peanut milk powder prepared by different methods
65
4.24 Protein contents of peanut milk powder prepared by different methods
65
4.25 Fat contents of peanut milk powder prepared by different methods
66
4.26 Carbohydrates contents of peanut milk powder prepared by different methods
67
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4.27 Crude fiber contents of peanut milk powder prepared by different methods
67
4.28 Ash contents of peanut milk powder prepared by different methods
68
4.29 Total solids of peanut milk powder prepared by different methods
69
4.30 pH values of peanut milk powder prepared by different methods
69
4.31 Proximate composition of peanut milk and powder by normal soaking method
70
4.32 Proximate composition of peanut milk and powder 1% NaHCO3 method
71
4.33 Proximate composition of peanut milk and powder by roasting method
72
4.34 Proximate composition of peanut milk and powder by pressure blanching for zero minutes method
73
4.35 Proximate composition of peanut milk and powder by pressure blanching for 2 minutes method
74
4.36 Proximate composition of peanut milk and powder by pressure blanching for 3 minutes method
75
4.37 Proximate composition of peanut milk and powder by pressure blanching for 5 minutes method
76
4.38 Comparison among proximate composition parameters of peanut milk using different methods
77
4.39 Comparison among proximate composition parameters of peanut milk powder using different methods
78
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LIST OF PLATES
Plate Caption Page No. 3.1 Prepared peanut milk 28 3.2 Pressure blanching using autoclave 29 3.3 Prepared peanut milk powder 30 3.4 Tall-type spray dryer (SMST-15, Kolkata) 31 3.5 Different parts of spray dryer 33 3.6 Formal titration (Estimation of milk protein) 37 3.7 Socs Plus (Estimation of milk powder fat content) 42 3.8 Digital pH meter 47
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LIST OF ABBREVIATIONS
Abbreviation Description Agril. Agricultural Agril. Engg. Agricultural Engineering Engg. Engineering FAE Faculty of Agricultural Engineering ANGRAU Acharya NG Ranga Agriculture
University IGKV Indira Gandhi Krishi Vishwavidyalaya
M. Tech. Master of Technology SPT Skin prick testing A.P Andhra Pradesh SSA Sub Saharan Africa GME Ground nut milk extract SPCM Soy peanut cow milk PMK Peanut milk kefir WMK Whole milk kefir HACCP Hazard Analysis and Critical control
point FPSY Fermenting milk from peanut and soy
milk SPCY Soy peanut cow milk yoghurt IP Incubation period SMP Skimmed milk powder CMC Carboxymethyl cellulose RSM Response surface methodology OAA Over all acceptability CMY Cow milk yoghurt PMY Peanut milk yoghurt RH Relative humidity PV Peroxide value OSI Oxidative stability index AFB1 Alfa toxin B1 PB Phosphate buffer NDPM Non- defatted peanut milk PDPM partially de fatted peanut milk EC Electrical conductivity PPM Parts per million HC Hydroxychavicol SDE Steam distillation extraction TLC Total least count US United States DV Daily value LDPE Low density poly ethylene AOAC Association of official analytical chemists
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LIST OF SYMBOLS
Abbreviation Description % percent
wb Wet basis et al. Et alibi Fig. Figure g Gram h Hour Mn Manganese S Sulphur P Phosphorus Mo Molybdenum A Ampere V Volt Lit Litre Kw Kilo watt MHz Mega hertz 0C Degree centigrade Mpa Mega Pascal Fe Iron Cr Chromium µm Micro meter i. e. That is kW Kilowatt MT Milliontonne mm Millimeter m.c. Moisture content m/s Meter per second No. Number S Second wt. Weight cps Centipoise second Ca Calcium G* Complex modulus K Potassium
aw water activity °F Degree Fahren heat wk Week l/h litre per hour ml/min milliliter per minute N Normality HCl Hydrochloric acid H2SO4 Sulphuric acid NaOH Sodium hydroxide
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nutritive value of peanut milk and powder were compared. The moisture in raw
peanuts was 5.25% (wb). The raw peanuts recorded a good amount of protein
(25.48%) which is good for health. The carbohydrates which consist mainly sugars
were also present which occupied the share of nutritive value up to 17.43%. The
fat and ash contents in the peanuts were found to be 47.27 and 1.84% respectively.
In normal soaking method of peanut milk preparation the values of
proteins, carbohydrates, fat and ash were 3.68%, 4.70%, 2.16% and 0.24%
respectively. In soaking in 1% NaHCO3 method of peanut milk preparation, the
values were 3.11%, 5.58%, 1.86% and 0.26% respectively. In roasting method of
peanut milk preparation the values were 3.23%, 3.78%, 3.53% and 0.18%
respectively. Pressure blanching peanuts for zero minutes gave the values of
proteins, carbohydrates, fat and ash as 3.74%, 5.02%, 1.83% and 0.18%
respectively. The values of milk prepare by pressure blanching for 2 minutes were
3.51%, 5.05%, 1.76% and 0.19% respectively. Pressure blanching for 3 minutes
method of peanut milk preparation the values of proteins, carbohydrates, fat and
ash in peanut milk were 3.34%, 4.58%, 1.63% and 0.15% respectively. Pressure
blanching for 5 minutes method of peanut milk preparation the values of proteins,
carbohydrates, fat and ash in peanut milk were 3.40%, 5.33%, 1.76% and 0.15%
respectively.
Peanut milk powder prepared by normal soaking, soaking in 1% NaHCO3,
roasting, pressure blanched for zero minutes, 2, 3, and 5 minutes, the values of
proteins, carbohydrates, fat, ash and crude fiber in peanut milk powder were;
27.05%, 18.22%, 45.89%, 2.86% and 1.11%; 29.97%, 18.79%, 42.18%, 2.45%
and 1.31%; 27.44%, 15.25%, 48.35%, 2.12% and 1.26%; 30.88%, 19.72%,
40.89%, 2.49% and 1.56%; 28.25%, 14.61%, 46.94%, 2.28% and 2.07%; 28.25%,
18.87%, 44.03%, 1.86% and 1.34%; 28.70%, 19.51%, 43.19%, 1.77% and 1.53%
respectively. It was observed that all the quality parameters of milk were less
compared to the raw peanuts. On comparison between peanut milk and peanut milk
powder, it was noticed that nutritionally peanut milk powder was superior.
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Hkh iks’kd rRo dk 17-43% fgLlk vf/kxzg.k djrk gSA olk vkSj jk[k fd ek=k ewwWxQyh esa 47-
27% vkSj 1-84% ik;h x;hA
ewWxQyh ds nw/k cukus dh lkekU; lks[kus fd fof/k esa izksVhu, dkcksZgkbbsV, olk vkSj jk[k dh
ek=k dze”k% 3-68%, 2-61%, 4-70% vkSj 0-24% Ikk;h x;hA ewWxQyh ds nw/k cukus fd 1 % NaHCO3 lkekU;
lks[kusa fd fof/k esa ek=k dze”k% 3-11%, 5-58%, 1-86% vkSj 0-26% ik;h xbZA ewWaxQyh nw/k cukus dh jksLVhax
fof/k esa izksVhu dkcksZgkbbsV olk vkSj jk[k fd ek=k dze”k% 3-23%, 3-78%, 3-53% vkSj 0-18% ik;h x;hA
ewWxQyh dk “kqU;fefuV nkc;qDr esa ;s rRo dze”k% 3-74%, 5-02%, 1-83% vkSj 0-18% ek= ik;h x;hA nks
fefuV nkc;qDr Cykafpax esa 3-40%, 5-33%, 1-76% vkSj 0-15% ik;h x;hA
ewWaxQyh ds nw/k dk ikmMj cukus ds lkekU; vko”kks’k.k, 1 % NaHCO3 esa vo”kks’k.k, jksfLVax, 0,
2, 3 vkSj 5 fefuV nkc;qDr Cykafpx esa izksVhu, dkcksZgkbbsV, olk, jk[k vkSj izkjfEHkd js”ks ewWaxQyh ds
nw/kikmMj esa dze”k% 27-05%, 18-22%, 45-89%, 2-86% vkSj 1-11%% 29-97%, 18-79%, 42-18%, 2-45% vkSj 1-
31%% 27-44%, 15-25%, 48-35%, 2-12% vkSj 1-26%% 30-88%, 19-72%, 40-89%, 2-49% vkSj 1-56%% 28-25%, 14-
61%, 46-94%, 2-28% vkSj 2-07%% 28-25%, 18-87%, 44-03%, 1-86% vkSj 1-34%% 28-70%, 19-51%, 43-19%, 1-77%
vkSj 1-53% fo”y’k.k esa nw/k dk xq.koRRkk ?kVd dPps eqwqWxQyh ds rqyuk esa de ik;k x;kA ewwqWXkQyh ds
nw/k vkSj ikmMj ds rqyuk esa ;s uksfVl fd;k x;k dh iks’k.k ;qDr ewWaxQyh nw/k ikmMj vPNk x;k x;kA
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CHAPTER-I
INTRODUCTION
1.1 General:
Peanuts (Arachis hypogaea) originated in South America where the crop
existed for thousands of years. Peanuts played an important role in the diet of the
Aztecs and other native Indians in South America and Mexico. India is one of the
largest producers of oilseeds in the world and occupies an important position in the
Indian agricultural economy. It is estimated that nine oilseeds namely groundnut,
rapeseed-mustard, soybean, sunflower, safflower, sesame, niger, castor and
linseed, accounted for an area of 23.44 million hectares with the production of
25.14 million tons (Madhusudhana, 2013). Groundnut is called as the ‘King’ of
oilseeds. Groundnut is also called as wonder nut and poor men’s cashew nut.
Groundnut is one of the most important cash crops of our country.
1.2 Peanut production in the world:
The major peanut producing countries in the world are China, India,
Nigeria, Argentina, Sudan, Burma, Indonesia and the United States of America
(Table 1.1).
Table 1.1 Production of peanuts in the world
Country Production (%)
China 42.4
India 14.5
Nigeria 7.8
United States 4.4
Burma 3.7
Indonesia 3.1
Argentina 2.6
Sudan 2.2
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1.3 Peanut production in the India:
Gujarat is the single largest as well as the best quality peanuts producer
accounting for over 40% of total groundnut produced in the country. Groundnut
production, within the country, is mainly concentrated in five states including
Gujarat, Andhra Pradesh, Tamil Nadu, Karnataka, Rajasthan and Maharashtra
accounting for nearly 90 % of the total production of peanut in the country. The
remaining peanut cultivated area is scattered in the states of Madhya Pradesh, Uttar
Pradesh, Punjab, and Orissa (Table 1.2).
Table 1.2 Production of peanuts in the India
State Production (%)
Gujarat 40.7
Andhra Pradesh 17.6
Tamil Nadu 10.8
Karnataka 9.0
Rajasthan 8.2
Maharashtra 5.6
Madhya Pradesh 3.6
1.4 Nutritional composition of peanuts:
Peanuts are rich in essential nutrients. In a 100 g serving peanuts provide
567 calories and are in an excellent source (defined as more than 20% of the daily
value, DV) of several B vitamins, several dietary minerals, such as manganese
(95% DV), magnesium (52% DV), and phosphorus (48% DV) and dietary fiber.
Peanuts also contain about 25 g protein per 100 g serving, a higher proportion than
in many tree nuts.
Some studies show that regular consumption of peanuts is associated with a
lower risk of mortality specifically from certain diseases. However, the study
designs do not allow cause and effect to be inferred. According to the US Food and
Drug Administration, "Scientific evidence suggests but does not prove that eating
1.5 ounces per day of most nuts (such as peanuts) as part of a diet low in saturated
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fat and cholesterol may reduce the risk of heart disease. Nutritional value of 100 g
peanuts is given in Table 1.3.
Table 1.3 Nutritional compositions of peanuts
Principle Nutrient value (g) Energy 567 kcal Carbohydrates 16.13 Protein 25.80 Total fat 49.24 Dietary fiber 8.5 Ash 2.33
1.5 Uses of peanuts:
Peanuts have been used as a major source of edible oil and protein meal
and considered highly valuable for human and animal nutrition in developing
countries (Fekria et al., 2012). Peanuts are rich source of multiple nutrients and
their consumption is associated with various health benefits, including reduced
cardiovascular disease risk (Mattes et al., 2008). It has been reported that eating
peanuts or peanut butter could provide the body with the daily requirements of
many of the essential vitamins and minerals such as vitamin A, vitamin E, folate,
magnesium, zinc, iron, calcium, and dietary fiber. Peanuts have been developed
into a food for infants suffering from various forms of malnutrition and for
individual with lactose intolerance allergies (Considine and Considine, 1997).
1.6 Peanut milk:
Peanut milk is a non-dairy beverage created using peanuts and water.
Recipe variations include salt, sweeteners, and grains. It does not contain
any lactose and is therefore suitable for people with lactose intolerance. Similar in
production to almond milk, soy milk, and rice milk, the peanuts are typically
ground, soaked, sometimes heated, and then filtered through a fine filter: the
resulting liquid is considered the "milk".
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1.7 Peanut milk powder:
Nutrient rich non-dairy extract of peanut kernel can substitute dairy milk
powder for preparation of any sweets. It is ideal for ice cream, thick shakes,
beverages and other protein rich preparations. Water extract of healthy
electronically sorted peanut kernels, free from redskin, treated at particular
temperature and pH to make it similar to cow milk. The milk prepared is filtered
and pasteurized to avoid any microbial contamination. This milk is free from
cholesterol, lactose and any Trans-fatty acids. It contains peculiar phytochemicals
and herbal nutrients of peanut. Milk is subjected to dehydration and drying at strict
temperature level and time. The powder is fortified to enrich it with various
nutrients. Powder is packed in food grade prescribed material and stored in cool
conditions.
Hence, keeping the above points in mind the present research entitled
“Studies on the preparation of peanut milk and milk powder” has been undertaken
with the following objectives:
1. To study the different methods of peanut milk preparation.
2. To compare the quality of peanut milk prepared by different methods.
3. To prepare the dehydrated peanut milk (powder) using spray drying
technique.
4. To compare the nutritive value of peanut milk and powder.
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CHAPTER-II
REVIEW OF LITERATURE
This chapter deals with the review of literature on major fields related to
present study of preparation of peanut milk and milk powder using different
methods. The related literature pertaining to the research topics are briefly
summarized in this chapter under different heads and sub-heads.
2.1 Nutritional composition of peanuts:
Cabanillas et al. (2015) studied to analyze the influence of thermal
processing on the IgE binding properties of three forms of peanut, its effects in the
content of individual allergens and IgE cross-linking capacity in effector cells of
allergy. Three forms of peanut were selected and subjected to thermal processing.
Immunoreactivity was evaluated by means of immunoblot or ELISA inhibition
assay. Specific antibodies were used to identify changes in the content of the main
allergens in peanut samples. The ability of treated peanut to cross-link IgE was
evaluated in a basophil activation assay and Skin Prick Testing (SPT). The results
showed that thermal/pressure treatments at specific conditions had the capacity to
decrease IgE binding properties of protein extracts from peanut. This effect went
along with an altered capacity to activate basophils sensitized with IgE from
patients with peanut allergy and the wheal size in Skin Prick Testing.
Derbyshire (2014) carried out a growing body of literature has been
published on the health benefits of peanuts, but the biological effects of high-oleic
peanuts, along with their organoleptic characteristics have not been reviewed to
date. In this paper, examination of evidence showed that high-oleic peanuts
provide a spectrum of nutrients and have improved sensory properties and
technological advances, such as enhanced shelf life, beyond that of conventional
peanuts. This may be attributed to their oleic to linoleic ratio which is substantially
higher than normal peanuts. In terms of their biological effects, high-oleic peanuts
appear to be no more allergenic, and could even be less allergenic than
conventional peanuts. There is also emerging evidence that high-oleic peanuts may
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improve lipid profile and markers of glycemic control. Further randomized
controlled human trials are now needed to build on animal and in vitro studies.
Kumar and Ravi Shankar (2013) investigated the physico-chemical,
proximate and nutritionally valuable minerals were determined aiming to compare
raw and roasted groundnut seeds. The results indicated that total ash content of raw
groundnut (4.6%) was higher than the roasted groundnut (4.1%) seeds. Crude
protein content of roasted groundnut was higher (26.1%) when compared to that of
raw groundnut (24.9%). Crude carbohydrates levels of raw groundnut (25.3%) are
lower when compared with that of roasted groundnut (26.5%). Crude fat ranged
from 39.1% in raw groundnut to 39.6% in roasted groundnut. Crude fiber
percentage both in raw (2.9%) and roasted (3.1%) conditions were good. The
moisture content of the raw groundnut (4.1%) was more than the roasted groundnut
(3.6%) because of not exposure to heat. Seeds showed higher energy values both in
raw and roasted conditions. Significant amount of minerals like potassium,
calcium, magnesium, phosphorus, and zinc were present both in raw and roasted
conditions. Based on statistical analysis the results showed highly significant
differences (P < 0.05) between the raw and roasted seeds.
Madhusudhana (2013) carried out a survey about the ground nut area,
production and productivity in India, Andhra Pradesh state and Anantapuram
district. The study calculated the area, production and productivity of groundnut
crop at national level, state level and district level during 1996-2000 to 2001-2008.
The present comparative analysis of groundnut production was done in
Anantapuram district, A.P, during 1996-2000 to 2001-2006. The groundnut crop
area, production and productivity at national level, state level and Anantapuram
district level of during 1996-2000 to 2001-2006 were collected and presented
graphically. Based on the results collected some conclusions were made about the
improving the production of groundnut crop.
Settaluri et al. (2012) concluded that the peanuts are consumed in many
forms such as boiled peanuts, peanut oil, peanut butter, roasted peanuts, and added
peanut meal in snack food, energy bars and candies. Peanuts are considered as a
vital source of nutrients. Nutrition plays an important role in growth and energy
Page 27
gain of living organisms. Peanuts are rich in calories and contain many nutrients,
minerals, antioxidants, and vitamins that are essential for optimum health. All
these biomolecules are essential for pumping vital nutrients into the human body
for sustaining normal health. This paper presents an overview of the peanut
composition in terms of the constituent biomolecules, and their biological
functions. It highlights the usefulness of considering peanuts as an essential
component in human diet considering its nutritional values.
Hillocks et al. (2011) reported the bambara groundnut originated in West
Africa but has become widely distributed throughout the semi-arid zone of sub-
Saharan Africa (SSA). Despite its high and balanced protein content, bambara
remains under-utilised because it takes a long time to cook, contains anti-
nutritional factors and does not dehull easily. Bambara yields well under
conditions which are too arid for groundnut, maize and even sorghum. Its drought
tolerance makes bambara a useful legume to include in climate change adaptation
strategies. There is little documented evidence of trade in bambara but
circumstantial evidence indicates considerable international demand. More
attention should be given, therefore, to market research and development, with
crop improvement programmes being more market-led, if bambara is to make a
greater contribution to household income and rural development in sub-saharan
Africa.
Margaret et al. (1997) concluded that the effects of two thermal processing
methods on physical and sensory properties of a beverage prepared from finely
ground, partially defatted roasted peanuts were determined. Samples were either
bottle-processed at 72°C for 2 min or 111°C for 8 min after homogenizing at 72°C,
or kettle-pasteurized for 2 min at 72, 77 or 82°C before homogenizing at 72, 77 or
82°C, respectively. Harsher thermal processing parameters increased the
suspension stability and viscosity of bottle-processed beverage by 175 and 87%,
respectively, but had no influence on kettle-pasteurized beverage. Total solids (%)
and colour were not adversely affected by thermal processing. Beverage that was
kettle-pasteurized and homogenized at 72°C had low viscosity (6.1-8.4 cps),
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typical roasted peanut flavour and little or no chalky mouthfeel, irrespective of
whether carrageenan or mono-diglyceride were added to the formulation.
2.2 Nutritional composition of peanut milk:
Adeiye et al. (2013) investigated the influence of processing variables on
some properties of stored groundnut milk extracts (GME). GMEs were prepared
from fresh, roasted (170°C, 25 min) and steeped (water, 20 min) groundnuts. The
groundnuts were milled, sieved, the slurry boiled, homogenized, pasteurized and
stored. The GMEs packaged in glass bottles, plastic bottles and low density
polyethylene sachets, were stored in the refrigerator for 28 days and at room
temperature for three days and tested for proximate composition, physico-chemical
and sensory properties. The protein contents of the GME varied between 2.05 to
2.33%; fat, 2.40 to 3.48%; carbohydrate, 5.50 to 5.60%; viscosity, 7.33 and 7.56
cP; titratable acidity, 0.10 to 0.14% and pH, 6.82 to 6.85. The protein and fat
contents of GMEs decreased with storage time regardless of the packaging
materials and processing pretreatment. The GMEs were not different in terms of
taste and mouth feel but recorded significant differences in colour, appearance and
flavour.
Jain et al. (2013) developed a small scale process for the production of
peanut milk from M-522 variety of peanut. Three treatments i.e. traditional, 1%
NaHCO3 soaking and pressure blanching (at 121°C, 15 psi for 2, 3 and 5 min)
were given for the preparation of peanut milk. The milks so obtained were
analyzed for chemical composition and also subjected to organoleptic evaluation
using nine point hedonic scale by semi trained panel of judges. Peanut milk
prepared by pressure blanching (at 121°C, 15 psi for 3 min) was found most
acceptable method. The proximate composition of the most acceptable peanut milk
prepared by pressure blanching (at 121 °C, 15 psi for 3 min) was found to be
moisture 88.22%, ash 0.16%, fat 1.65%, protein 3.27% and total solids 11.78%.
Based on the results it was concluded that the pressure blanching was found most
acceptable method for the preparation of peanut milk beverage although it had the
negative effect on the protein and total solid extraction.
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Kpodo et al. (2013) reported the investigations were conducted employing
a three-component constrained mixture design to formulate milk blends from soy
milk, peanut milk and cow milk. Variations in chemical composition and physico-
chemical properties of 10-soy-peanut-cow milk (SPCM) formulations were
studied. Variations in soy-peanut-cow milk (SPCM) concentrations influenced to
varying levels the chemical composition and physico-chemical properties of
blends. SPCM formulations containing significant amounts of all three ingredients
used (60-70% soy milk, 20-27% peanut milk and 7-20% cow milk) had high crude
protein and fat values ranging from 2.20-2.51% and 5.00-6.35% respectively.
Increasing soy concentrations caused relative increases in protein content while fat
content increased with increasing peanut concentrations. SPCM formulations were
high in the minerals Fe and Mn relative to cow milk which was high in Ca and Zn
content. Trends in pH were contrary to titratable acidity and increased with
increasing soy milk content but decreasing cow milk content. SPCM formulations
demonstrated acceptable non-Newtonian behavior and consistency indices.
Bensmira and Jiang (2012) studied the characteristics of peanut-milk in
kefir preparation. Rheological characteristic, textural properties, mineral elements
and amino acid composition of kefir made from peanut milk (PMK), 7/3
peanut/skimmed-milk (70% PMK) had been investigated using whole-milk kefir
(WMK) as a control. Results showed that, PMK sample had the highest (p<0.05%)
complex modulus (G*), firmness and the lowest (p<0.05%) adhesiveness.
However, both 70% PMK and WMK had high minerals and essential amino acids
content.
Zhang et al. (2012) found that the choice and consumption of emulsifier
and stabilizer are one of the main factors affecting stability for peanut mango milk.
The stabilizer of mango peanut milk was guar gum, the dosage was 0.15%; The
optimum emulsifier was the mixture of sucrose fatty acid ester, monoglyceride and
polyglycerol fatty acid ester (1:1:1), the dosage was 0.24%. The study developed a
nutrient-rich, stable state of the organization of peanut mango milk.
Ovie and Ovie (2007) investigated the Growth, food conversion efficiency
and survival of H. longifilis fed diets with varying levels of protein in which 10%
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of fish meal was replaced with groundnut cake were studied for 84 days. Fish fed
the diet containing 44.17% crude protein showed the best weight gain, specific
growth rate, food conversion ratio and efficiency. There was no significant
difference (P>0.05) in all the growth parameters and the survival rate of the fish.
Addition of fishmeal to fish diets increases feed efficiency and growth although it
is a very expensive ingredient. In northern Nigeria 1kg of fishmeal costs about five
hundred Naira while its equivalent of groundnut cake is about one hundred Naira.
Cost – effectiveness of diets could be improved by replacing fishmeal with more
economical protein sources such as groundnut cake.
Tano-Debrah et al. (2005) studied the production of vegetable milk, such as
soymilk and peanut milk is being vigorously promoted in many developing
countries to supplement animal milk or become a cheaper alternative to the latter.
These vegetable extracts (milk) are comparable in nutritional quality to milk of
animal sources. However, limitations to their use, particularly in infant feeding,
include high bulk density, low calcium content and the possible presence of anti-
nutritional factors. Dehulled and pretreated local varieties of cowpea and peanut
were blended in the ratio 1:3 and co-milled. An aqueous extract was produced and
then heated to solubilize the starch. It was then treated with a prepared malt
enzyme extract at a predetermined concentration. The bulk-density was
significantly reduced in the malt-extract hydrolyzed products, as indicated by the
reduction in viscosity (in one case from 878333 to 45.4 cps at 95°C). The reducing
sugar content also increased from 0.024% in the unhydrolyzed sample to 2.43% in
the malt-extract treated sample. The proximate composition of the malt-extract
treated product was: protein 4.2%, fat 4%, total carbohydrate 5.0%, and ash 0.4%.
Total solids content was 7.6%.
Roberts et al. (2004) reported the imitation milk obtained from the seeds of
the groundnut was fermented with a culture pack consisting of a mixture of
Lactobacillus bulgaricus and Streptococcus thermophilus to obtain a yoghurt-like
product. The final pH (4.20.08) and titratable acidity (1.6210.40%) fell within the
acceptable ranges of 4.00 to 4.50 and 1.20 to 2.20%, respectively, indicative of
good yoghurt. Fermentation also brought about increases in the contents of total
Page 31
ash, calcium, potassium and phosphorus when compared with an unfermented milk
sample. The protein content showed an increase from 2.980.03% in the
unfermented to 5.950.08% in the fermented sample, while the reverse was
observed with respect to the crude fibre and total fat contents. Sensory evaluation
indicated a level of acceptance comparable with commercial milk yoghurt and the
products were adjudged microbiologically safe.
Saleem et al. (2003) reviewed that peanut is an annual herbaceous plant
belonging to family leguminoseae. Parachinar variety of peanut was used in this
study. Both roasted and raw peanuts were used to prepare milk. It was found that
soaking of roasted peanuts in ordinary water with pH 7 for 1 hour at 40°C gave
good results. Peanut milk was prepared by grinding the pre-shelled and pre-soaked
roasted peanuts in an osterizer with same amount of simple water. The resulting
slurry was then diluted with water so that 100 g shelled peanuts produced 100 ml
of peanut milk. The peanut milk was then blended with various levels of skim milk
powder and sugar. The blending levels of skim milk and sugar 10% and 1% on
total solid basis of peanut respectively were more stable and acceptable as
compared to other treatments. The results showed that the peanut milk blend had
more protein contents and minerals like Mg, K and Fe than cow’s milk.
Lee and Beuchat (1992) reported the influence of processing conditions on
chemical, physical and sensory characteristics of aqueous extracts of peanuts
(peanut milk) prepared for lactic bacterial fermentation was investigated. Soaking
peanuts in 1.0% NaHCO3 before extraction resulted in a lighter colored milk, and
homogenization enhanced lightness. Cooking peanuts before grinding reduced total
solids and protein contents of milk. Hexanal concentration was greatly reduced by
cooking peanuts for 10 min. The most satisfactory conditions for preparing peanut
milk consisted of soaking peanuts in 0.5% NaHCO3, cooking for 10 min and
homogenizing the extract at 4000 psi.
Lee and Beuchat (1991) reported the effects of fermentation of aqueous
extracts of peanuts (peanut milk) with Lactobacillus delbrueckii ssp. bulgaricus
and Streptococcus salivarius ssp. thermophilus, separately and in combination, on
selected chemical and sensory qualities were investigated. Changes in pH,
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titratable acidity and viable cell populations indicated that there was a synergistic
interaction between L. delbrueckii ssp. bulgaricus and S. salivarius ssp.
thermophilus during fermentation. Analysis of headspace volatiles revealed that
hexanal, which is one of the compounds responsible for undesirable green/beany
flavor in peanut milk, completely disappeared as a result of fermentation. The
acetaldehyde content of peanut milk increased during fermentation. Changes in
concentrations of these volatile compounds were correlated with sensory
evaluation scores which showed that a significant (P less than or equal to 0.05)
decrease in green/beany flavor and a significant increase in creamy flavor occurred
as a result of fermentation.
2.3 Preparation on Peanut milk based products:
Roopesh et al. (2016) investigated the water activity (aw) is a major factor
affecting pathogen heat resistance in low-moisture foods. However, there is a lack
of data for aw at elevated temperatures that occur during actual thermal processing
conditions, and its influence on thermal tolerance of pathogens. The objective of
this study was to gain an in-depth understanding of the relationship between
temperature-induced changes in aw and thermal resistance of Salmonella in all
purpose flour and peanut butter at elevated temperatures. The thermal resistance
(D80-values) of Salmonella in all purpose flour and peanut butter with initial aw of
0.45 (measured at room temperature, 20°C) was determined via isothermal
treatment of small (< 1 g) samples. When increasing sample temperature from 20
to 80ºC in sealed cells, the aw of all purpose flour increased from 0.45 to 0.80, but
the aw of peanut butter decreased from 0.45 to 0.04. The corresponding estimated
D80-values of Salmonella in all purpose flour and peanut butter with room
temperature aw of 0.45 were 6.9 ± 0.7 min and 17.0 ± 0.9 min, respectively.
Song and Kang (2016) evaluated the efficacy of a 915 MHz microwave
with 3 different levels to inactivate 3 serovars of Salmonella in peanut butter.
Peanut butter inoculated with Salmonella enterica serovar Senftenberg, S. enterica
serovar Typhimurium and S. enterica serovar Tennessee were treated with a 915
MHz microwave with 2, 4 and 6 kW and acid and peroxide values and color
Page 33
changes were determined after 5 min of microwave heating. Salmonella
populations were reduced with increasing treatment time and treatment power. Six
kW 915 MHz microwave treatment for 5 min reduced these three Salmonella
serovars by 3.24 e4.26 log CFU/g. Four and two kW 915 MHz microwave
processing for 5 min reduced these Salmonella serovars by 1.14e1.48 and
0.15e0.42 log CFU/g, respectively. Microwave treatment did not affect acid,
peroxide, or color values of peanut butter. These results demonstrate that 915 MHz
microwave processing can be used as a control method for reducing Salmonella in
peanut butter without producing quality deterioration.
Esther et al. (2015) concluded that the common problem faced by
developing countries is the deficiency in protein intake by poor people. This
problem demands incentive policies for consumption of vegetable protein with low
cost and good quality. As a solution to the problem, the production of two peanut
based beverages had been sought due to their adequate source of protein, wide
offer and low cost. It had also been taken under consideration total titratable
acidity, pH, moisture content, proteins, and ashes from the ‘‘peanut milk’’ enriched
with umbu and guava pulps, stored at a temperature of 18°C (0.4°F) for 150 days
with follow ups every 30 days. Results for acidity regarding the beverage enriched
with umbu pulp were superior to the beverage enriched with guava pulp; as to
protein amount, it was observed a decrease in the studied formulations during
storage.
Hung et al. (2015) evaluated to ensure the safety of the peanut butter ice
cream manufacture, a Hazard Analysis and Critical Control Point (HACCP) plan
has been designed and applied to the production process. Potential biological,
chemical, and physical hazards in each manufacturing procedure were identified.
Critical control points for the peanut butter ice cream was then determined as the
pasteurization and freezing process. The establishment of a monitoring system,
corrective actions, verification procedures, and documentation and record keeping
were followed to complete the HACCP program. The results of this study indicate
that implementing the HACCP system in food industries can effectively enhance
food safety and quality while improving the production management.
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Kabeir et al. (2015) carried out to develop probiotic fermented beverage
based on roasted peanut milk. Peanut was roasted (100°C for 20 min) to improve
nutrient component, facilitate the removal of the crust and decrease the beany
flavor of peanut. Roasted peanut and yellow millet were soaked in water (12 h),
blended (5 min) and filtered using a double layered cheese cloth to prepare the
roasted peanut milk and millet beverage. Yellow millet beverage was boiled (70°C
for 3 min), malted millet flour (1:5 (w/w) was added, cooled (37°C), maintain 14
min to prepared millet thin porridge. Different formulation based on roasted peanut
milk partially substituted with 15% (A), 30% (B), and 45% (C) with millet thin
porridge was prepared. At maximum growth (18 h), there was 3.15, 2.9, 2.89, 2.76,
2.43, and 2.1 log CFU/ml increase in fermented peanut milk, millet thin porridge,
cow milk, blend (B), blend (A) and blend (C), respectively. At 24 h fermentation,
the number of the strain in all fermented beverages still above the number required
to presence in probiotic food which is at least 6 log CFU/ml fermented products;
except blend C (5.77 CFU/ml) didn't fulfill probiotic requirements in food. The pH
significantly (P<0.05) decreased due to increase acids production from
fermentation of sugar.
Claudia et al. (2014) explored the commercial probiotic products are dairy-
based, and the development of non-dairy probiotic products could be an alternative
for new functional products. The peanut-soy milk was inoculated with six different
lactic acid bacteria, including probiotic strains and yeasts and fermentation was
accomplished for 24 h at 37°C and afterwards, another 24 h at±4°C. Bulgaricus
yogurt starter culture reached cell concentrations of about 8.3 log CFU/mL during
fermentation. The Lactobacillus acidophilus probiotic produced significant
amounts of lactic acid (3.35 g/L) and rapidly lowered the pH (4.6). Saccharomyces
cerevisiae did not completely consume the available sugars and consequently
produced low amounts of ethanol (0.24 g/L). Lactic acid production increased, and
12 h was required to reach a pH value of 4.3. An average of 58% and 78% of
available carbohydrates was consumed when single and co-cultures were
evaluated, respectively. The final content of ethanol was 0.03% (v/v) or less, which
classified the final beverage as non-alcoholic.
Page 35
Kpodo et al. (2014 a) reported that yoghurt produced by fermenting milk
from peanut and soy milk were considered to have poor sensory attributes due to
the off-flavours legumes generate in food products. Proximate analysis and
consumer studies were carried out on the 10 FPSY and 10 DPSY formulations
developed using a three component constraint mixture design. Balanced
Incomplete Block Design was used to assign samples to consumers and the
optimized formulations were validated. Samples of the FPSY were high in crude
protein and fat whereas the DPSY formulations were high in carbohydrate and
total solids. Consumers preferred more soy milk in their full fat vegetable milk
yoghurts but preferred more cow milk in their low fat vegetable milk yoghurt.
FPSY and DPSY formulations with the most preferred sensory attributes were 0.68
Soy milk, 0.25 peanut milk and 0.07 Cow milk; and 0.65 Soy milk, 0.22 defatted
peanut milk and 0.13 cow milk respectively.
Kpodo et al. (2014 b) reviewed the acidification of milk by lactic acid
bacteria enhance the aggregation of milk proteins to form yoghurt gels with
enhanced texture, colour and viscosity. A three component constrained mixture
design was employed to develop 10 soy-peanut-cow milk formulations which were
fermented with Lactobacillus bulgaricus and Streptococcus thermophilus (1:1) into
soy-peanut-cow milk yoghurt (SPCY). The effect of ingredient variations on
microbial acidification, colour, susceptibility to syneresis, water holding capacity
and viscosity were determined. Titratable acidity increased with increasing cow
milk content and trends in pH were contrary to titratable acidity. Rheologically all
products investigated were non-Newtonian and had better consistencies as cow
milk content increased in samples and peanut milk content decreased. The water
holding capacities of yoghurt samples increased with increasing soy milk content.
Formulations without cow milk were the least susceptible to syneresis.
Mohamed et al. (2014) evaluated the protein quality of foods by
incorporating legumes or cereal protein isolates and/or flour in blends is one of the
main focuses of the international research community. The aim of this study was to
produce peanut milk based yoghurt and to evaluate its physicochemical and
organoleptic characteristics. The skimmed milk powder was added to peanuts milk
Page 36
at the concentration of 0% (sample A), 5% (sample B), 10 % (sample C), and 15%
(sample D). The physicochemical and sensory characteristics of the products were
subsequently analyzed at 0, 5, and 10 days. The results of chemical analysis
showed protein contents of 11.55, 14.7, 18.55, and 20.65 % for the samples A, B,
C, and D, respectively. Fat contents was varied and in the range of 3.35-4.55%,
while total solid was ranged from 19.7 to 27.09 %. The pH value varied between
4.41 to 4.76 while acidity (P ≤ 0.05) was increased from 1.28, to 1.78 % with
increasing levels of skimmed powder milk. Among all types of yoghurts, peanuts
milk-based yoghurt fortified with 10 g/100 ml skimmed milk represented highest
(P ≤ 0.05) scores of all sensory attributes and remain superior in this regards in
both fresh and mature yoghurt.
Razig and Yousif (2010) reported the utilization of groundnut milk in
manufacturing the spread cheese in Sudan was investigated. Groundnut milk was
prepared from grinded groundnut seeds. Four samples of spread cheese were
prepared from groundnut milk with different levels of skim milk powder 0, 5, 10
and 15. The prepared spread cheese samples were stored for 6 months at 30±2°C.
Analyses of chemical composition were carried on prepared spread cheese samples
and the analyses were carried out at intervals 0, 1, 2, 3, 4, 5 and 6 months during
storage period. The chemical analyses of spread cheese samples at zero time
processing were for total solids 35.79, 37.91, 39.59 and 41.49%, the protein
content 12.82, 14.35, 15.98 and 17.56%, the fat content 14.98, 14.99, 14.99 and
15.0%, the ash content 4.16, 4.18, 4.21 and 4.23% for samples A, B, C and D
respectively.
Yadav et al. (2010) concluded the fermented milk product was developed
by using peanut milk. The level of incubation period (IP), skimmed milk powder
(SMP), carboxymethyl cellulose (CMC) was optimized using response surface
methodology (RSM). Central composite rotatable design was used with three
independent variables i.e. IP (16–20 h), SMP (3–5%) and CMC (0.1–0.3%). CMC
was found effective in reducing the synersis of curd samples. The developed curd
samples had moisture 84.8 ± 0.28%, protein 3.2 ± 0.12%, fat 3.5 ± 0.10%, ash 0.5
± 0.05%, carbohydrate 8.0% (wb), peak viscosity 291.4 ± 3.52 cP, firmness 1.3 ±
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0.15 N, synersis 32.1 ± 0.2 mL 100 g)1 and acidity (as % lactic acid) 0.58 ± 0.02.
It had OAA score of 7.8 ± 0.2 on nine-point hedonic scale. Based on compromise
optimisation, the conditions recommended were IP as 18 h, SMP, 4.24% and
CMC, 0.19% for making peanut milk–based fermented curd with 83.4%
desirability.
Isanga and zhang (2009) reported the peanut milk for yoghurt production
was prepared by fortifying peanut milk (w12 g/100 g total solids) with 4 g/100 g
skimmed milk powder. The final product was subjected to physicochemical
analysis using cow milk yoghurt (CMY) as a control throughout the study. Peanut
milk yoghurt (PMY) had higher protein content, fat, water holding capacity and
lower susceptibility to Syneresis than CMY. PMY had lower lactose level (1.73
g/100 ml) compared to CMY (4.93 g/100 ml). Generally both PMY and CMY had
high mineral composition and contained high amounts of essential amino acids.
PMY also contained a higher proportion of unsaturated fatty acids than saturated
fatty acids as compared to CMY. Therefore, in terms of fatty acid composition,
PMY could be considered to be more health promoting than CMY. Sensory
evaluation revealed that though PMY had better sensory texture scores than CMY,
its sensory appearance, flavor and overall acceptability scores were lower than
those of cow milk yoghurt.
Isanga and Zhang (2007) investigated the possibility of producing yoghurt
based on peanut milk was studied. Stirred yoghurt was prepared from a mixture of
70% peanut milk and 30% cow milk. The final product was subjected to
physiochemical analysis and sensory evaluation. Whole milk yoghurt was used as
a control throughout the investigation. Investigations revealed that the peanut milk
based yoghurt had 3.47% protein content, 81.02% water holding capacity and
34.43% susceptibility to syneresis compared to 2.76, 65.03 and 47.40% for the
whole milk yoghurt, respectively. The titratable acidity of the peanut milk based
yoghurt was 80°T and pH was 4.57.
Diarra et al. (2005) reported the early 1950s; numerous reports have been
published suggesting that peanut milk and peanut milk based products can be
prepared in a wide variety of ways. Emphasis has shifted from preparing
Page 38
inexpensive milk like beverages, very nutritious but somewhat lacking consumers
appeal, to using the peanut milk or peanut protein isolates as an animal milk
extender changing flavor, to develop more attractive fermented products, and to
precipitate proteins from the milk in order to get a curd called “tofu,” and to
produce cheese analogs. Great attention has been paid to the improvement of the
stability, sensory properties, and shelf-life of the milk, using physical and chemical
treatments.
Sanders et al. (1999) concluded that blanching, seed coat removal is often a
processing step in peanut manufacturing but the general peanut industry consensus
is that shelf-life reduction occurs as a result of the process. In order to examine the
effects of blanching on shelf-life, runner-type peanuts were blanched using total
heating time and final temperature in a 3 X 3 factorial experiment. In each of nine
treatments, heating began at 32°C and increased incrementally through six heating
zones over a total time of 30, 45, or 60 min to a final temperature of 76.7, 87.8, or
98.9°C. Blanched peanuts from each treatment and non blanched control samples
were stored at 26°C and ambient RH and were sampled over a 28-wk period.
Peroxide value (PV) and oxidative stability index (OSI) of blanched and non
blanched peanuts were similar indicating no meaningful shelf-life differences.
Hao and Brackett (1988) investigated the ability of F. aurantiacum to
reduce the aflatoxin B1 (AFB1) concentration was determined by inoculating
about 109 stationary phase cells in AFB1-contaminated phosphate buffer (PB).
Non-defatted peanut milk (NDPM) and partially defatted peanut milk (PDPM).
The AFB1 concentration and cell populations were determined periodically
throughout the incubation (30°C). After 24 hr, the concentration of AFB1
decreased about 40% in PB, 23% in NDPM and 74% in PDPM. Viable cell
population decreased less than one log10 CFU/mL in all liquids but increased
about 0.8 log10 unit in control PDPM. AFB1 recovery increased about 30% in
proteolysed PDPM but proteolysis had no effect on recovery from non-defatted
peanut milk.
Beuchat and Nail (1978) concluded the extraction procedures were
examined for their suitability to yield desirable peanut milks for fermentation by
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four strains of lactic acid bacteria. Studies revealed that a procedure in which
peanuts were soaked in 1.0% sodium bicarbonate for 16-18 hr, drained, washed
with tap water, ground, steeped for 4-5 hr in tap water, and filtered resulted in milk
most desirable for fermentation. The addition of lactose (2%) to pasteurized peanut
milk before fermenting with Lactobacillus bulgaricus NRRL B-1909 and L.
acidophilus for 3 days at 37°C resulted in a custard-like product having 0.38-
0.53% titratable acidity at pH 4.76-4.43, respectively. Sensory panel evaluations of
blended, fermented peanut milks containing added sucrose (2%) and fruit
flavorings showed that the products were acceptable and competed favorably with
flavored buttermilk. Fermented peanut milk substituted for buttermilk in a corn
muffin recipe resulted in products with organoleptic characteristics not
significantly (P < 0.05) different from those of the control.
2.4 Spray drying behavior on different quality products:
Chegini et al. (2014) investigated the performance of a spray dryer for the
preparation of whey powder. Its main objective is to categorize unknown samples
using analysis of discrimination function between the operating variables and
powder properties in two or more naturally occurring groups. In this work, spray
drying was performed in a pilot-scale concurrent spray dryer. Results The PH of
whey powder with 15 % solid content was lower than the PH of whey powder with
30 % solid content. Furthermore, the PH of the whey dried at inlet (outlet) air
temperature of 180°C (106°C) was lower than the whey dried at 145°C (87°C).
Substances with higher acidity had higher electrical conductivity (EC) as well. The
mean particle diameters of the powders produced by pilot plant spray dryer were in
the range of 11.26–18.23 lm. By increasing the temperature and heating duration,
the amount of PH reduced and the diameter of the particles increased. Moreover,
by increasing the percentage of the solid content, the PH increased, while the solid
mass carried away by the outlet air decreased. Small particles sprayed by the two-
fluid nozzles, led to less amount of total dissolved solids.
Costa et al. (2014) reported to this study aimed at contributing to the
development of new foodstuffs made by soursop pulp powder obtained by spray
Page 40
drying. Different concentrations of maltodextrin DE 20 (15, 30, and 45%) were
added to commercial soursop pulp, which was dehydrated afterwards. The
following analyses were carried out: water activity, moisture, pH, soluble solids,
acidity, ascorbic acid, hygroscopicity, degree of caking, and rehydration time. The
results obtained for the three powder treatments (15, 30 and 45% of maltodextrin)
were, respectively: water activity (0.19a±0.00; 0.20a±0.00; 0.18a±0.01); moisture
(1.17c±0.12; 1.47b±0.05; 1.82a±0.06); pH (3.75a±0.05; 3.73a±0.06; 3.70a±0.03);
soluble solids (89.67a±0.00; 89.84a±0.00; 90.00a±0.06); acidity (3.01a±0.02;
1.91b±0.03; 1.24c±0.03); ascorbic acid (18.90a±0.00; 14.48b±0.00; 11.26b±0.78);
hygroscopicity (5.93a±0.40; 3.82b±0.16; 3.28b±0.38); degree of caking
(78.36a±2.86; 35.38b±6.07; 24.77b4.89), and rehydration time (02.03a±0.46;
01.16ab±0.50; 0.59b±0.30). The soursop powders with 30 and 45% of
maltodextrin had few significant differences in terms of physicochemical and
hygroscopic characteristics, which allow us to consider the percentage of 30% of
maltodextrin, in this study, as the best percentage for soursop pulp atomization.
Febriyenti et al. (2014) concluded the haruan extract has a big potential as
an active pharmaceutical ingredient for various medical conditions. However,
instability of the liquid extract at room temperature has been a hindrance in the
formulation stage of the preparation. Thus, dried Haruan extract has been produced
using freeze drying and spray drying methods. In the spray drying method, a
prototype of a spray dryer equipped with an ultrasonic atomizer was used with a
different ultrasonic frequency. The spray dried extract showed better physical
properties when compared to the freeze dried extract; with smaller size and
narrower particle size distribution in the higher ultrasonic frequency. Voluminous
flakes of the dried extract were produced in the freeze drying method while spray
drying method produced almost spherical shape of particles. No structural changes
in the secondary protein structure were seen regardless of the method.
Ishiwu et al. (2014) investigated the Samples of spray-dried soy milk
powder were produced at various spray-dryer inlet air temperatures and
characterized. Soybean seed was sorted, boiled for 40 min, manually dehulled, wet
milled using plate mill and sieved with muslin cloth to obtain water soluble
Page 41
extract (soy milk). Soy milk powder showed high protein content (62.05±0.23%),
fat (19.92±0.08%), ash (1.41±0.02 %) and available lysine (5.02±0.29%), but low
carbohydrate content (12.85±0.01 %) and moisture (3.66±0.23%). The physical
properties showed that the mean total solid of the samples was 10.33±0.33%, pack
bulk density (0.57±0.00 g/ml), while the mean viscosity was 47 mpas. The sample
spray-dried at 204°C had solubilities of 48% and 78% at reconstituting water
temperatures of 40°C and 80°C, respectively while the sample produced at 260°C
showed lower solubility of 38.46% and 45.01% when temperature of reconstitution
were 40°C and 60°C, respectively.
Afroz et al. (2013) investigated the milk and milk products are ideal foods
for all age groups in both rural and urban people all around the world. This study
reports microbiological status of powder milk samples and antibiotic susceptibility
pattern of E. coli and Staphylococcus aureus isolated from powder milk samples
collected from different area of Dhaka, Bangladesh. Twelve samples were
collected and seven of them were found acceptable according to codex
Alimentarius and ICMSF in terms of total viable count and total coliform. E. coli
was isolated from 11 samples and Staphylococcus aureus was isolated from 6
samples. E. coli isolated were resistant to 5 antibiotics and Staphylococcus aureus
isolates were resistant to 6 antibiotics. Hygienic conditions during production and
post-processing should be improved according to HACCP (Hazard Analysis and
Critical Control Points) guidelines to improve the microbiological quality and
safety of powder milk products.
Gnanalaksshmi et al. (2013) reported the sensory evaluation of yoghurt
prepared from yoghurt powder. In spray drying outlet air temperature of 70˚C was
found to be optimum as the percentage of survival of yoghurt culture was higher.
The survival of yoghurt culture was found to be maximum in fresh yoghurt,
followed by freeze dried powder and spray dried powder. Significant difference
with regard to colour and appearance was noticed between fresh yoghurt,
reconstituted spray dried yoghurt and reconstituted chemically stabilized yoghurt.
Statistical analysis of data with regard to body and texture revealed that there was
significant difference (p < 0.05) between fresh yoghurt and reconstituted spray
Page 42
dried yoghurt. But there was no such significant difference noticed in the case of
reconstituted chemically stabilized yoghurt.
Jones et al. (2013) reported the surface compositions of food powders
created from spray drying solutions containing various ratios of sodium caseinate,
maltodextrin and soya oil have been analysed by Electron Spectroscopy for
Chemical Analysis. The results show significant enrichment of oil at the surface of
particles compared to the bulk phase and, when the non-oil components only are
considered, a significant surface enrichment of sodium caseinate also. The degree
of surface enrichment of both oil and sodium caseinate was found to increase with
decreasing bulk levels of the respective components. Surface enrichment of oil was
also affected by processing conditions (emulsion drop size and drying
temperature), but surface enrichment of sodium caseinate was relatively insensitive
to these. The presence of ‘‘pock marks’’ on the particle surfaces strongly suggests
that the surface oil was caused by rupturing of emulsion droplets at the surface as
the surrounding matrix contracts and hardens.
Atkins et al. (2012) studied the Spray drying of milk powder is an energy
intensive process and there remains a significant opportunity to reduce energy
consumption by applying process integration principles. The ability to optimally
integrate the drying process with the other processing steps has the potential to
improve the overall efficiency of the entire process, especially when exhaust heat
recovery is considered Integration schemes that are acceptable from an operational
point of view are examined in this paper. The use of evaporated water is an
important factor to achieve both energy and water reductions. This will restrict the
amount of heat recovery but minimise operational risk from heat exchanger
fouling.
Tee et al. (2012) studied the Piper betle L., more commonly known as betel
or local name of Sirih belongs to the family Piperaceae. Previous researches had
shown that the leaves of P. betle possess tremendous beneficial effects including
antimicrobial, antioxidant, anti-diabetic, wound healing and gastro-protective
properties. This is due to the present of the two bioactive component;
propenylphenols; which is the Hydroxychavicol and Eugenol. In this study, betel
Page 43
leaves extract was dried by spray drying for easy handling and the preservation of
bioactive compounds. The properties of dried powder were investigated in terms of
bioactive compound, hydroxychavicol (HC) content, particle size distribution,
moisture content, powder yield and hygroscopicity. The optimal properties of
spray-dried powder obtained from this study were 229.29 ppm of hydroxychavicol,
5.48 μm in size; 6.99% in moisture content; 10.53 g of powder yield and 28.88%
of hygroscopicity.
Patel et al. (2009) investigated that the systemic review covers the design
and critical elements of spray drying, types of spray drier, critical parameters of
spray drying, innovations in spray drying, and its applications in pharmaceutical
field.
Keogh et al. (2004) studied the spray-dried milk powders have a median
particle size of 30–80 μm. Roller-dried powder particles, which are larger (about
150 μm), are preferred for chocolate making. Spray-drying variables were
therefore studied to produce larger powder particles for chocolate. Vacuole volume
and moisture contents typical for spray-dried powders were obtainable at air outlet
temperatures up to 90°C. The particle size of the chocolate mix after refining and
the Casson yield value of the chocolate after conching reached minimum values
using spray-dried powders with median particle size values of 132–162 μm. These
minimum values in the chocolates were also correlated with higher contents of
free-fat and lower vacuole volumes in the powders. The spray-dried powders
produced good quality British style chocolates, where the particle size after
refining is conventionally <26 μm, but not continental chocolates, where the
particle size should be <20 μm.
Shiratsuchi et al. (1995) reported the contributors to sweet and milky odor
attributes of spray-dried skim milk powder have been investigated. Spray-dried
skim milk was homogenized with water, and the volatiles were isolated by
simultaneous steam distillation extraction (SDE). The odor concentrate was
fractionated by silica gel TLC. Two polar fractions with sweet and milky odors
were analyzed by GC and GC-MS. To elucidate the compounds directly
contributing to the characteristic flavor, these fractions were further fractionated by
Page 44
a preparative GC and the separated fractions and peaks were sniffed. Nonanoic
acid, decanoic acid, and dodecanoic acid were responsible for a sweet, fatty, and
butter like odor; undecanoic acid contributed a sweet and butter-like odor; and y-
undecalactone, y-dodecalactone, a y-lactone, d-decalactone, and d-undecalactone
gave a sweet and milky odor.
Shiratsuchi et al. (1994) reported the volatile flavor compounds of skim
milk powder have been investigated. Commercially processed spray-dried skim
milk was homogenized with water, and the volatiles were isolated by simultaneous
steam distillation-extraction under reduced pressure (SDE) using diethyl ether as
solvent. The odor concentrate was analyzed by gas chromatography and gas
chromatography-mass spectrometry. Among 196 individual peaks detected, 187
peaks were definitely or tentatively identified by mass spectrum and modified
Kovats indices. Major compounds were 48 hydrocarbons, 18 aldehydes, 20
ketones, 21 alcohols, 29 fatty acids, 8 esters, 2 furans, 7 phenolic compounds, 10
lactones, and 14 nitrogenous compounds, which constituted over 99 5% of total
volatiles recovered. Most of them originated by breakdown of the major
constituent of milk, especially fat to smaller, volatile chemicals or their secondary
reaction, or by transfer from the forage.
Sreenivasan et al. (1964) studied a process for the preparation of spray-
dried infant food containing 26% of protein and 18% of fat is described. The
product is based on a blend of coconut protein, groundnut protein isolate, skim
milk powder, dextrins and hydrogenated groundnut oil and is fortified with
vitamins and minerals. It is light cream in colour and reconstitutes readily in water.
Laboratory samples are free from Escherichia coli and other pathogenic anaerobes
and the total plate count is of the order of 15,600/g. When packed in polyethylene
bags (100 gauge) and stored in tin containers at 37°, it kept well for 9 months, the
losses of vitamins A and C and thiamine at the end of the storage period being 25,
32 and 20%, respectively.
Page 45
2.5 Development and characterization of peanut milk powder for
use in chocolate manufacture:
Brown et al. (2014) explored the feasibility of producing a soy-peanut,
chocolate-flavoured milk beverage with acceptable chemical and physico-chemical
properties from soybeans, peanuts and cocoa powder. Ten formulations were
processed by mixing three basic ingredients: soybeans (20g/100g-80g/100g),
peanuts (20g/100g-60g/100g) and cocoa powder (1g/100g-7g/100g). The
optimized proportions of the ingredients were obtained using a three-component,
constrained extreme lattice mixture design. The optimized product consisted of
54.0-58.5% soybeans, 37.0-42.0% peanut and 4.46 - 4.48% cocoa powder and had
an energy value of 124.103kJ/100g. Proximate analysis of the optimized products
indicated that the beverage has a protein content of 2.77%, fat content of 1.38%,
carbohydrate content of 1.26%, ash content of 0.32% and water content of 94.27%.
Aidoo et al. (2010) explored the feasibility of producing peanut–cowpea
milk for use in vegetable milk chocolates. Development of the vegetable milk
followed a 3 X 2 factorial design, with peanut–cowpea ratio (1:1, 1:2 and 1:3), and
treatment with enzyme (i.e. enzyme hydrolyzed and non-hydrolyzed milk) as the
factors. The milk was dehydrated and then milled using a hammer mill (mesh size
40). The ratio of cowpea to peanut affected the chemical and functional
characteristics of the vegetable milk. Vegetable milk made from 1:2 ratios of
peanuts: cowpea produced the most preferred chocolates. The successful
application of this study by industry will improve the utilization of the legume
crops and enhance their market value.
Deshpande et al. (2008 a) concluded that the optimization of a chocolate-
flavored, peanut–soy beverage was done using response surface methodology
(RSM). Twenty-eight beverage formulations were processed by mixing three basic
ingredients: peanut (X1 ¼ 30.6 g/100 g–58.7 g/100 g), soy (X2 ¼ 28.3 g/ 100 g–
43.5 g/100 g), and chocolate syrup (X3 ¼ 13.0 g/100 g–25.9 g/100 g). Parameter
estimates were determined by performing regression analysis with no intercept
option. L-pseudo-components were introduced to get equivalent second degree
models further used to generate contour plots. The regions of maximum consumer
Page 46
acceptability were identified and marked on these contour plots for each sensory
response. Optimum formulations were all the combinations of X1: 34.1 g/100 g–
45.5 g/100 g, X2: 31.2 g/100 g–42.9 g/100 g, and X3: 22.4 g/100 g–24.1 g/100 g
for SF-based; and X1: 35.8 g/100 g–47.6 g/100 g, X2: 31.2 g/100 g–43.5 g/100 g,
and X3: 18.3 g/100 g–23.6 g/100 g for SPI-based beverage formulations.
Deshpande et al. (2008 b) reported a new beverage product was developed
utilising two protein-rich oilseed sources, namely peanut and soy. Medium-roasted
peanut flour and chocolate flavour were incorporated to offer pleasant flavour
profile. The peanut–soy combination would also improve essential amino acid
profile, especially that of lysine, compared with an all-peanut product. A pilot-
plant scale beverage-processing protocol involved filtration, homogenization and
pasteurisation as the major operating steps. Beverage formulation employed a
three-component constrained mixture design. The low- and high-bound constraints
were determined for peanut (30.6–58.7%), soy (28.3–43.5%) and chocolate syrup
(13.0–25.9%) based on lysine content, viscosity and visual stability index values of
51-mg g) protein, 36.9 mPa s and 1.00, respectively. The beverage formulation and
processing protocol thus developed were the basis for further study on consumer
acceptability of the new chocolate-flavoured peanut–soy beverage.
Tamminga et al. (1977) reported the milk chocolate mass containing
salmonellas was prepared by mixing artificially contaminated milk powder with
the other ingredients at a temperature of about 40°C. From this mass bars were
made. S. east borne was reduced in numbers during 19 months from an initial
count of ca. 3 x 104 to ca. 3 x 102 per 100 g of chocolate. S. typhimurium died off
more rapidly, and was not detectable in about 55 g after 15 months, in spite of an
initial count of ca. 105 per 100 g. In these experiments the salmonellas in the milk
powder had had to survive the spraying procedure and the adverse conditions in the
dried powder. This may be the reason why S. east borne showed a distinctly better
survival on storage than the same serotype showed in previous experiments in
which the organism was added as a broth culture to the chocolate mix. With S.
typhimurium, however, a difference was hardly detectable.
Page 47
CHAPTER-III
MATERIALS AND METHODS
This chapter deals with the materials and methodologies used during
present investigation. The determination of various nutritional compositions of
fresh peanut milk and freshly prepared peanut milk powder was done using
standard techniques. All the studies and determinations were done in the College of
Agricultural Engineering, Bapatla, Guntur, and Post Harvest Technology Centre,
Bapatla, Acharya N.G. Ranga Agricultural University, Lam, Guntur (Andhra
Pradesh).
3.1 Procurement of raw materials:
The fresh peanuts used for the study were procured from local market,
Bapatla, Guntur District.
3.2 Technical programme of work:
The present study was carried out in the College of Agricultural
Engineering, Bapatla. All facilities required to conduct study were available in this
place.
Peanut milk was prepared by the following methods.
a. Traditional method (Normal soaking, Soaking in 1% NaHCO3 and
roasting)
b. Pressure blanching method (121°C at 15 psi for 0, 2, 3 & 5 min)
3.2.1 Dependent parameters:
1. Moisture Content
2. Ash
3. Fat
4. Protein
5. Crude fiber
6. Carbohydrates
7. pH
8. Total solids
Page 48
3.2.2 Independent parameter
a. Normal soaking
b. Soaking in 1%
c. Roasting
d. Pressure blanching
3.3 Preparation of peanut milk:
Peanut milk was
3.4 Traditional method:
3.4.1 Normal soaking:
(kernel: water) for 16 to 18 hours and they were be dehusked. The dehusked
kernels were washed with water and ground with hot water in a ratio of 1:6
(kernels to water) in the grinder. The slurry formed
peanut milk was produced
3.4.2 Soaking in 1%
NaHCO3 (1:3 ratio kernels to 1%
were dehusked. The dehusked kernels were
hot water in a ratio of 1:6 (kernels to water) in the grinder. The slurry formed
sieved by muslin cloth and peanut milk
removal of beany flavour in the final product, and to help so
3.4.3 Roasting: Sorted peanut seeds were roasted at 130°C for 28 min in an oven.
The seeds were de-skinned and weighed before being soaked in 0.5%
Independent parameters:
Normal soaking
Soaking in 1% NaHCO3
Pressure blanching
Preparation of peanut milk:
was prepared using two different methods as follows:
Traditional method:
Normal soaking: 100g of peanuts were soaked in water in a ratio of 1:3
: water) for 16 to 18 hours and they were be dehusked. The dehusked
kernels were washed with water and ground with hot water in a ratio of 1:6
(kernels to water) in the grinder. The slurry formed was sieved by muslin cloth and
produced (Plate 3.1).
Soaking in 1% NaHCO3: 100 g of peanuts were soaked for 16
(1:3 ratio kernels to 1% NaHCO3). After 16 to 18 h soaking, peanuts
dehusked. The dehusked kernels were washed with water and ground with
hot water in a ratio of 1:6 (kernels to water) in the grinder. The slurry formed
sieved by muslin cloth and peanut milk was produced. NaHCO3
removal of beany flavour in the final product, and to help soften the peanuts.
Plate 3.1 Prepared peanut milk
Sorted peanut seeds were roasted at 130°C for 28 min in an oven.
skinned and weighed before being soaked in 0.5%
prepared using two different methods as follows:-
100g of peanuts were soaked in water in a ratio of 1:3
: water) for 16 to 18 hours and they were be dehusked. The dehusked
kernels were washed with water and ground with hot water in a ratio of 1:6
sieved by muslin cloth and
soaked for 16–18 h in 1%
h soaking, peanuts
washed with water and ground with
hot water in a ratio of 1:6 (kernels to water) in the grinder. The slurry formed was
3 was used to the
ften the peanuts.
Sorted peanut seeds were roasted at 130°C for 28 min in an oven.
skinned and weighed before being soaked in 0.5% NaHCO3 for
Page 49
atleast 14 h. The de-skinned peanut kernels were washed with clean water. The
kernels were mixed with water in a ratio of 1:6 [peanuts (g): water (ml)] and
transferred to a blender where they were blended for 5 min. The slurry formed
sieved by muslin cloth and peanut milk
3.4.4 Pressure blanching:
Blanching of peanuts (100 g) were be done in an autoclave
temperature of 121°C and 15 psi for
blanched peanuts were soaked in water for 6 h in a ratio of 1:3 (kernels to water).
After soaking kernels were dehusked and ground in hot water in a ratio of 1:6
(kernels to water) in the grinder. The slurry formed
the peanut milk was prepared.
Plate 3.2 Pressure blanching using autoclave
3.5 Preparation of peanut milk powder using spray dryer:
The spray drying process was carried out in P
Center, Bapatla using
principle of co-current flow atomization. Spray dryer consisted of feed pump,
atomizer, air heater, air disperser, drying chamber, and systems for exhaust air
cleaning and powder rec
with the nozzle fits to 1 mm size. The
chamber with feed flow rate of 20 m
skinned peanut kernels were washed with clean water. The
kernels were mixed with water in a ratio of 1:6 [peanuts (g): water (ml)] and
transferred to a blender where they were blended for 5 min. The slurry formed
in cloth and peanut milk was produced.
Pressure blanching:
Blanching of peanuts (100 g) were be done in an autoclave
temperature of 121°C and 15 psi for 0, 2, 3 and 5 minutes respectively. Then,
blanched peanuts were soaked in water for 6 h in a ratio of 1:3 (kernels to water).
After soaking kernels were dehusked and ground in hot water in a ratio of 1:6
(kernels to water) in the grinder. The slurry formed was sieved by muslin cloth and
repared.
Plate 3.2 Pressure blanching using autoclave
eanut milk powder using spray dryer:
The spray drying process was carried out in Post Harvest
, Bapatla using (S.M. Science Tech., India). The spray dryer works on the
current flow atomization. Spray dryer consisted of feed pump,
atomizer, air heater, air disperser, drying chamber, and systems for exhaust air
cleaning and powder recovery. The maximum capacity of the dryer was 1.30 l/h
with the nozzle fits to 1 mm size. The peanut milk was fed in to the dry
chamber with feed flow rate of 20 ml/min and inlet air temperature was
skinned peanut kernels were washed with clean water. The
kernels were mixed with water in a ratio of 1:6 [peanuts (g): water (ml)] and
transferred to a blender where they were blended for 5 min. The slurry formed was
Blanching of peanuts (100 g) were be done in an autoclave (Plate 3.2) at a
2, 3 and 5 minutes respectively. Then,
blanched peanuts were soaked in water for 6 h in a ratio of 1:3 (kernels to water).
After soaking kernels were dehusked and ground in hot water in a ratio of 1:6
sieved by muslin cloth and
Plate 3.2 Pressure blanching using autoclave
arvest Technology
. The spray dryer works on the
current flow atomization. Spray dryer consisted of feed pump,
atomizer, air heater, air disperser, drying chamber, and systems for exhaust air
overy. The maximum capacity of the dryer was 1.30 l/h
was fed in to the drying
air temperature was maintained
Page 50
at 130°C temperature
ambient conditions.
Plate 3.3 Prepared peanut milk powder
3.5.1 Technical specification of Tall
1. The main chamber is made of stainless steel AISI
diameter 300 mm and nominal length, with
2. The main chamber with air Disperser at the ceiling which induces circular
motion of droplets
formation. The cyclone is also made of stainless steel AISI
3. Spray dryer is
INCOLOY heat
with anti-blocking device along with orifice of 3 (0.7 mm, 1.0 mm and 1.25
mm) different replaceable size, to be operated by
4. Peristaltic feed pump
(Siemens ∕ ABB
is operated by AC
import) for precise RPM
and dynamically balanced
5. Electrically PID temperature controller
temperature up to 300°C maximum and electronic digital temperature
indicates for outlet
6. Spray dryer it is operates 32 Amp main switch
with neutral and earth and air compressor (SH6
C temperature. The obtained powder was stored in LDPE covers under
Plate 3.3 Prepared peanut milk powder
Technical specification of Tall-type spray drier:
The main chamber is made of stainless steel AISI-304 having nominal
diameter 300 mm and nominal length, with conical bottom (Plate 3.4
The main chamber with air Disperser at the ceiling which induces circular
motion of droplets-hot air flow mixture facilitating spherical shape
formation. The cyclone is also made of stainless steel AISI-
Spray dryer is electrically heated (9.6 KW) with electrical heater having
INCOLOY heat-resisting sheath. Two fluid nozzles pneumatically operated
blocking device along with orifice of 3 (0.7 mm, 1.0 mm and 1.25
mm) different replaceable size, to be operated by compressed air.
Peristaltic feed pump (Plate 3.5) with AC motor with frequency converts
∕ ABB make-import) for precise RPM control. Centrifugal blower
is operated by AC motor with frequency converts (Siemens
import) for precise RPM control. The blower will have aluminum casing
and dynamically balanced stainless steel impeller.
Electrically PID temperature controller-Indicates with sensor for inlet air
temperature up to 300°C maximum and electronic digital temperature
indicates for outlet air temperature
Spray dryer it is operates 32 Amp main switch ∕ MCB of 3 phases (415
with neutral and earth and air compressor (SH6-Airmatic air compressor)
was stored in LDPE covers under
304 having nominal
(Plate 3.4).
The main chamber with air Disperser at the ceiling which induces circular
hot air flow mixture facilitating spherical shape
-304.
electrically heated (9.6 KW) with electrical heater having
resisting sheath. Two fluid nozzles pneumatically operated
blocking device along with orifice of 3 (0.7 mm, 1.0 mm and 1.25
compressed air.
with AC motor with frequency converts
import) for precise RPM control. Centrifugal blower
motor with frequency converts (Siemens ∕ ABB make-
rol. The blower will have aluminum casing
Indicates with sensor for inlet air
temperature up to 300°C maximum and electronic digital temperature
∕ MCB of 3 phases (415 V)
Airmatic air compressor)
Page 51
is operated by 16 Amp main switch ∕ MCB of 3 phases (415 V) with neutral
and earth.
Plate 3.4 Tall-type spray dryer (SMST-15, Kolkata)
3.5.2 Spray drying chamber:
Air circulating with the chamber keeps a flow pattern, this prevent the
deposition of partially dried product on the wall or atomizer. Air movement and
temperature of inlet air influences the type of final product.
Spray drying involves four stages of operation:
1. Atomization of liquid feed into a spray chamber;
2. Contact between the spray and the drying medium;
3. Moisture evaporation; and
4. Separation of dried products from air stream
Page 52
a) Tall-type spray dryer
c) Feed pump
type spray dryer b) Panel board
c) Feed pump d) Spray dryer nozzle
d) Spray dryer nozzle
Page 53
e) Nozzle
g) Compressor
Plate 3.5
3.5.3 Atomization:
The purpose of the atomizer is to meter flow into the chamber, produce
populations of liquid particles of the desired size and distribute those liquid
particles uniformly in the drying chamber. The selection of a specific
made based on the feedstock, the required powder properties, the dryer type and
capacity and the atomizer capacity.
e) Nozzle f) Feed outlet and atomizer
g) Compressor h) Pressure controller
Plate 3.5 Different parts of spray dryer
The purpose of the atomizer is to meter flow into the chamber, produce
populations of liquid particles of the desired size and distribute those liquid
uniformly in the drying chamber. The selection of a specific
the feedstock, the required powder properties, the dryer type and
atomizer capacity.
f) Feed outlet and atomizer
h) Pressure controller
The purpose of the atomizer is to meter flow into the chamber, produce
populations of liquid particles of the desired size and distribute those liquid
uniformly in the drying chamber. The selection of a specific atomizer is
the feedstock, the required powder properties, the dryer type and
Page 54
3.5.4 Spray–air contacts:
During spray–air contact, droplets usually meet hot air in the spraying
chamber either in co-current flow. In co-current flow, the product and drying
medium passes through the dryer in the same direction. In this arrangement, the
atomized droplets entering the dryer are in contact with the hot inlet air, but their
temperature is kept low due to a high rate of evaporation taking place.
3.5.5 Moisture evaporation:
When droplets come in contact with hot air, evaporation of moisture from
their surfaces takes place. The large surface area of the droplets leads to rapid
evaporation rates, keeping the temperature of the droplets at the wet-bulb
temperature.
3.5.6 Separation of dried products:
The dry powder is collected at the base of the dryer and removed by a
pneumatic system with a cyclone separator. The selection of equipment depends on
the operating conditions, such as particle size, shape, bulk density, and powder
outlet position.
3.5.7 Feed pump:
A peristaltic pump is a type of positive displacement pump used for
pumping a variety of fluids. The fluid is contained within a flexible tube fitted
inside a circular pump casing. A rotor with a number of "6 rollers" attached to the
external circumference of the rotor compresses the flexible tube. As the rotor turns,
the part of the tube under compression is pinched closed thus forcing the fluid to be
pumped to move through the tube.
3.5.8 Nozzle:
Most food industries applications use stainless steel inserts. However,
stainless steel nozzles are often available and have excellent resistance to abrasion
and good corrosion resistance for most feedstock.
3.5.9 Pressure nozzle atomizer:
Liquid is forced at 2 kg/cm2 pressure through a small aperture. The droplet
size produced from the nozzle varies directly with feed rate and feed viscosity, and
inversely with pressure.
Page 55
3.5.10 Powder recovery:
Powder recovery is expressed as the weight percentage of the final product
compared to the total amount of the materials sprayed (Sansone et al., 2011).
Powder recovery (%) = ������������������������
�����������100
3.6 Proximate analysis of peanut milk and milk powder:
3.6.1 Estimation of moisture content in milk and milk powder:
The moisture content was determined following the method described in
AOAC (2000). To determine the moisture content, initially the oven was stabilized
(105°C) for the temperature. About 10 g of samples each of peanut milk and milk
powder were kept in the oven for 24 h at 103±2°C. Samples were then brought out
from the oven and weighed. Immediately after weighing the samples were replaced
in the oven for further removal of water. The method was continued till the entire
moisture was evaporated and there was no appreciable difference between two
consecutive weighing. The moisture content was calculated using the following
formula.
3.6.1.1 Calculation:
Moisture content (%) = (�₁��₂)
�₁��x 100
Where,
W1 = Weight in g of the dish with the material before drying
W2 = Weight in g of the dish with the material after drying
W = Weight in g of the empty dish
3.6.2 Estimation of protein content on milk by Pyne’s method (formal
titration):
3.6.2.1 Principle:
Standard procedure of AOAC (2000) the protein content in milk can be
estimated rapidly by means of formal titration. Formaldehyde in excess readily
Page 56
combines with free, i.e. unprotonated amino groups of amino acids to give methyl
derivatives. This reaction causes an isoelectric amino acid to lose a proton from the
NH3+ group of the zwitterions form. The proton so liberated can be titrated directly
with alkali and multiplied by pyne’s constant (1.7) to give protein content of milk
samples. Addition of potassium oxalate before titrating helps to estimate all
calcium as insoluble calcium oxalate from calcium caseinate complex.
H3N+CHRCOO- → H2NCHRCOO- + H+ H2NCHRCOO- + 2HCHO → (NHOCH2)
CHRCOO-
3.6.2.2 Apparatus:
Conical flask, pipette, burette
3.6.2.3 Reagents:
Potassium oxalate solution – saturated
Formaldehyde solution- 40%, neutral
Sodium hydroxide solution- 0.1N
Phenolphthalein solution – 1% in ethyl alcohol, 95% by volume.
3.6.2.4 Procedure:
10 ml of milk sample was taken in a 100 ml conical flask (Plate 3.6). Then
1 ml of phenolphthalein indicator solution and 0.4 ml saturated potassium oxalate
solution were added to it. The solution was left aside for about 2 minutes. Then the
milk was titrated (neutralized) to a faint pink colour with standard NaOH solution.
Then 2 ml of neutral formaldehyde solution was added (previously
neutralized to phenolphthalein with 0.1N NaOH solution). Then the sample was
titrated with the same standard NaOH solution to the same end point as before. The
volume of NaOH required for the second titration was recorded.
Page 57
3.6.2.5 Calculation:
The protein content of milk is given by
Protein content
Where,
V = Volume in ml of 0.1
1.7 = Pyne’s constant or normal factor.
3.6.3 Estimation of protein
Standard procedure of AOAC
16% of the total make
multiplied by 6.25 to arrive at the value of the crude protein.
3.6.3.1 Materials:
Sulphuric acid (Sp.gr.1.84)
Mercuric oxide
Potassium sulphate
Sodium hydroxide
Na2S2O3.5H2O
Plate 3.6 Formal titration
The protein content of milk is given by
Protein content (%) = V x 1.7
V = Volume in ml of 0.1 N NaOH used for second titration
1.7 = Pyne’s constant or normal factor.
rotein content in milk powder by using Kjeldhal method:
Standard procedure of AOAC (2000) in most proteins, nitrogen constitutes
16% of the total make-up and hence, the total nitrogen content of
to arrive at the value of the crude protein.
Sulphuric acid (Sp.gr.1.84).
Mercuric oxide.
sulphate.
Sodium hydroxide – Sodium thiosulphate solution: 600 g NaOH and 50 g
O were dissolved in distilled water and made to one litre.
second titration
jeldhal method:
n most proteins, nitrogen constitutes
up and hence, the total nitrogen content of the sample is
600 g NaOH and 50 g
to one litre.
Page 58
Indicator solution: Methyl red 0.2 g/100 mL ethanol, methylene blue 0.2
g/100 mL ethanol. For mixed indicator, two parts of methyl red solution
were added to one part of methylene blue solution.
Boric acid 4% solution.
Standard HCl or H2SO4, 0.02 N
Boiling chips and/or Glass beads
3.6.3.2 Procedure:
1. 100 mg of the sample (containing 1-3 mg nitrogen) was taken and
transferred to a 30 mL digestion flask.
2. 1.9 ± 0.1 g potassium sulphate and 80 ± 10 mg mercuric oxide and 2 mL
conc. H2SO4 were added to the digestion flask. If sample size was more
than 20 mg dry weight, 0.1 mL H2SO4 was added for each 10 mg dry
material.
3. Boiling chips were added and the sample was digested till the solution
became colourless.
4. After cooling the digest, the sample was diluted with a small quantity of
distilled ammonia-free water and transferred to the distillation apparatus.
The kjeldahl flask was rinsed with successive small quantities of water.
5. Then 100 mL conical flask containing 5 mL of boric acid solution was
taken with a few drops of mixed indicator with the tip of condenser dipped
below the surface of the solution.
6. Then 10 mL of sodium hydroxide - sodium thiosulphate solution was added
to the test solution in the apparatus.
7. Then the solution was distilled and the ammonia on boric acid was
collected (At least 15-20 mL of distillate was collected).
8. The tip of the condenser was rinsed, and the solution was titrated against
the standard acid until the first appearance of violet colour, the end point.
9. A reagent blank with an equal volume of distilled water was run and the
titration volume was subtracted from that of sample litre volume.
Page 59
3.6.3.3 Calculation:
���������������(�/��������)
=(����� − �������) × ���������× 14.01
����ℎ�(�)
Crude protein content = 6.25 × Nitrogen content
3.6.4 Estimation of fat content of milk by Rose Gottleib method:
3.6.4.1 Principle:
Standard procedure of AOAC (2000) the sample was treated with ammonia
and ethyl alcohol; the former to dissolve the protein and the latter to precipitate the
proteins. Fat was extracted with diethyl ether and petroleum ether. Mixed ethers
were evaporated and the residue was weighed. This method was considered
suitable for reference purposes. Strict adherence to details was essential in order to
obtain reliable results.
3.6.4.2 Apparatus:
Mojonnier fat extraction flask or any other suitable extraction tube (as per
IS specification).
Cork or stopper of synthetic rubber unaffected by usual fat solvents.
100 ml flat bottom flask with G/G joint or stainless steel or aluminium
dishes of 5.5 cm height and 9 cm diameter or glass bowl.
3.6.4.3 Reagents:
a) Ammonia Sp. gr. 0.8974 at 16°C
b) Ethyl alcohol (95%)
c) Diethyl ether, peroxide-free
d) Petroleum ether, boiling range 40-60°C
3.6.4.4 Procedure:
10 g of sample (liquid milk) was weighed accurately, and transferred to
extraction tube. 1.25 ml of ammonia sp. gr. 0.8974 was added, mixed and shaked
thoroughly. 10 ml ethyl alcohol was added and mixed again. 25 ml of diethyl ether
(peroxide free) stopper was added and shaked vigorously for about a minute. Then
25 ml petroleum ether (boiling range 40-60°C) was added and shaked again
vigorously for about half a minute. The solution was kept aside until the upper
ethereal layer had separated completely and was clear. (Alternatively low r.p.m.
Page 60
was used Mojonnier centrifuge). If there was a tendency to form emulsion, a little
alcohol was added to help separation of the layers.
The clear ethereal layer was decanted off into a suitable vessel (flask, glass
bowl, aluminum dish, etc.). The delivery end of the extraction tube was washed
with a little ether and the washings were added to the flask. The extraction of the
liquid remaining in the extraction tube using 15 ml of each solvent was repeated
twice every time. The ethereal extract to the same container was added and
evaporated off completely. The flask was dried in an air oven at 102 ± 2°C for two
hours, and cooled in a desiccator and weighed. The flask was heated again in the
oven for 30 min. The flask was cooled in a desiccator and weighed. The process of
heating and cooling was repeated and weighed until the difference between two
successive weights does not exceeded 1 mg. The fat was washed from the flask
with petroleum ether carefully without leaving any insoluble residue in the flask.
The flask was dried in the oven and reweighed. The difference in weights
represented the weight of fat extracted from the milk. Correct weight of extracted
fat by blank determination on reagents was used. If reagent blank was more than
0.5 mg the reagents were purified or replaced. The difference between duplicate
determinations obtained simultaneously by the same analyst should not be more
than 0.03 gm fat /100gm product.
3.6.4.5 Calculation:
Milk fat (%) = �����������
������������ x 100
3.6.5 Estimation of fat content of milk powder by Soxhlet apparatus method:
Standard procedure of AOAC (2000) the oil content of oilseed was determined
through solvent extraction process by using Soxhlet apparatus. The experimental
procedure is as follows.
1. The power was switched on and the set and actual temperature on the
display was ensured.
2. The beaker was washed thoroughly and the empty weight of beaker was
weighed.
3. The sample was weighed and transferred into the cellulose thimble.
Page 61
4. The water tap was opened and the flow of water through the water
condenser was ensured.
5. The thimble holder was kept along with the sample into beaker.
6. The beakers were taken to the main unit using the beaker trays, the slider
was pulled down the aluminum block and the beaker was loaded into the
system, perfect sealing of the beakers against the Teflon ring was ensured.
7. The required temperature & time for oil extraction and also for solvent
recovery in the controller was set.
8. Once the required temperature & time was reached recovery of solvent was
noticed.
9. The stopper was opened, so that the recovered solvent was allowed to flow
to the beaker to maintain the same level, on doing that. The boiling stage
and the extraction stage got completed.
10. After the completion of the boiling period the stopper was closed, in order
to collect the solvents in the solvent compartment.
11. During recovery, when the level of solvent touched below the bottom of the
thimble, the stopper was opened and the rate of condensation of solvent
was ensured and the delivery of the solvent was at equilibrium. This stage
of operation was called rinsing.
12. At the end of rinsing stage the stopper was closed tightly. All the solvent in
the extractor was recovered. Soxhlet apparatus as shown in Plate 3.7.
13. The beaker along with the oil was removed and kept inside the furnace for
some time and the weight of the beaker was taken.
Page 62
Oil yield (%) = �����
3.6.6 Estimation of ash content:
Standard procedure of AOAC, 2000 was followed to estimate the ash
content of maize de
combustible material has been burned off (oxidized completely).
3.6.6.1 Procedure:
1. The crucible and lid
that impurities on the surface of crucible we
2. The crucible was cooled
3. The crucible and lid
4. 5 g sample was weighed
heated over with lid half
the crucible and lid
5. The crucible was
not covered. T
fluffy ash. The sample was c
6. The ash with crucible and lid
Plate 3.7 Socs Plus
���������������������������������������������
��������������
Estimation of ash content:
Standard procedure of AOAC, 2000 was followed to estimate the ash
content of maize de-oiled cake. Ash is the residue remaining after all the
combustible material has been burned off (oxidized completely).
he crucible and lid was placed in the furnace at 5500C overnight to ensure
ies on the surface of crucible were burned off.
was cooled in the desiccator (30 min).
he crucible and lid was weighed to 3 decimal places.
was weighed into the crucible. The low Bunsen flame
with lid half covered. When fumes were no longer produced,
crucible and lid was placed in furnace.
The crucible was heated at 550oC overnight. During heating,
not covered. The lid was placed after complete heating to prevent loss of
The sample was cooled down in the desiccator.
he ash with crucible and lid was weighed when the sample turns to gray.
������× 100
Standard procedure of AOAC, 2000 was followed to estimate the ash
oiled cake. Ash is the residue remaining after all the
C overnight to ensure
low Bunsen flame was
o longer produced,
t. During heating, the lid was
after complete heating to prevent loss of
when the sample turns to gray.
Page 63
If not, the crucible and lid to the furnace was returned for the further
ashing.
3.6.6.2 Calculation:
Ash content (%) = �����������
��������������× 100
3.6.7 Estimation of crude fiber content in milk powder:
3.6.7.1 Materials:
Sulphuric acid solution (0.255±�.����): 1.25 g concentrated sulphuric
acid was diluted to 100 mL (concentration must be checked by titration).
Sodium hydroxide solution (0.313±�.����): 1.25 g Sodium hydroxide
was mixed in 100 mL distilled water (concentration must be checked by
titration with standard acid).
3.6.7.2 Procedure:
1. 2 g of ground material with ether or petroleum ether was extracted to
remove fat (Initial boiling temperature 35-38°C and final temperature
52°C). If fat content was below 1%, extraction it was omitted.
2. After extraction with ether, 2 g of dried material was boiled with 200 mL of
conc. sulphuric acid for 30 min with bumping chips.
3. The extract was filtered through muslin and washed with boiling water until
washings were no longer acidic.
4. The extract was boiled with 200 mL of sodium hydroxide solution for 30
min.
5. The extract was filtered through muslin cloth again and washed with 25 mL
of boiling 1.25% H2SO4, three 50 mL portions of water and 25 mL alcohol.
6. The residue was removed and transferred to ashing dish (preweighed dish
W1).
7. The residue was dried for 2 h at 130±2°C. The sample was cooled in
desiccators and weighed (W2).
8. The residue was ignited for 30 min at 600±15°C.
9. The residue was cooled in desiccators and reweighed (W3).
Page 64
3.6.7.3 Calculation:
Crude fibre in ground sample (%) = ����������������������(�����)�(�����)
�����������������×
100
3.6.8 Estimation of total solids (Gravimetric method):
3.6.8.1 Principle:
Pre drying of a test portion on a boiling water bath and subsequent
evaporation of the remaining water in a drying oven at a temperature of 105°C.
3.6.8.2 Apparatus:
Analytical Balance
Desiccator provided with an efficient desiccant ( for example freshly
dried silica gel with a hydrometric indicator
Boiling water bath provided with openings of adjustable size
Drying oven, ventilated capable of being maintained thermostatically at
102 + 2°C throughout the total working space.
Flat bottomed dishes of height 20 – 25 mm, diameter 50- 75 mm and made
of appropriate material (stainless steel, nickel or aluminium) provided with
well fitted readily removable lids.
Water bath capable of being maintained at 350 - 40°C
3.6.8.3 Preparation of sample:
The sample was transferred to a beaker, warmed slowly to 35– 40°C on a
water bath with careful mixing to incorporate any cream adhering to the sample.
The sample was cooled quickly to room temperature.
3.6.8.4 Procedure:
A dish with its lid was heated alongside in the drying oven for at least 1
hour. The lid on the dish was placed and immediately transferred to a desiccator.
The sample was allowed to cool to room temperature (at least 30 minutes) and
weighed to the nearest 0.1 mg. 5 ml of prepared sample was added to the sample
Page 65
and the lid on the dish was placed and weighed again. The dish without the lid was
placed on the vigorously boiling water bath in such a way that the bottom of the
dish was directly heated by the steam. The heating was continued till most of the
water was removed. The dish was removed from the water bath, and the underside
was wiped and placed in the oven alongside the lid and dried in the oven for 2
hours. The lid was placed and transferred to the desiccator. The dish was allowed
to cool and weighed to the nearest 0.1 mg. Again the dish with its lid alongside
was heated in the oven for 1 hour. The lid was placed on the dish and immediately
transferred to the desiccator. It was allowed to cool and weighed again. The
operation was repeated again until the difference in the two consecutive weighing
did not exceed 1 mg. The lowest mass was recorded.
3.6.8.4 Calculation:
Total solids (%) = �����
����� X 100
Where ,
M0= mass in g of dish + lid
M1 = mass in g of dish + lid and test portion
M2 = mass in g of dish + lid and dried test portion
Round the value obtained to nearest 0.01 % (m/m)
3.6.9 Estimation of carbohydrate content in milk and milk powder:
3.6.9.1 Principle:
Carbohydrates were first hydrolyzed into simple sugars using dilute
hydrochloric acid. In hot acidic medium glucose was dehydrated to hydroxymethyl
furfural. This compound formed with anthrone a green coloured product with an
absorption maximum at 630 nm.
3.6.9.2 Materials:
1. 2.5 N HCL
2. Anthrone reagent: 200mg anthrone was dissolved in 100 ml of ice cold
95% H2SO4.
Page 66
3. Standard glucose: 100mg was dissolved in 100 ml water. Working Standard
10 ml of stock diluted to 100 ml with distilled water
3.6.9.3 Procedure:
1. 100 mg of the sample was weighed into a boiling tube.
2. The sample was hydrolyzed by keeping it in a boiling water bath for three
hours with 5 ml of 2.5 N HCL and cooled to room temperature.
3. The sample was neutralized with solid medium carbonate until the
effervescence ceased.
4. The volume was made up to 100 ml and centrifuged.
5. The supernatant was collected and 0.5 and 1ml aliquots were taken for
analysis.
6. The standards were prepared by taking 0, 0.2, 0.4, 0.6, 0.8 and 1 ml of the
working standard. Zero served as blank.
7. The volume was made up to 1 ml in all the tubes including the sample tubes
by adding the distilled water.
8. Then 4 ml of anthrone reagent was added.
9. Then the sample was heated for 8 minutes in a boiling water bath.
10. Then it was cooled rapidly and the green to dark green colour was read at
630 nm.
11. A standard graph by plotting concentration of the standard on the X- axis
versus absorbance on the Y- axis was drawn.
12. From the graph the amount of carbohydrate present in the sample tube was
calculated.
3.6.9.4 Calculation:
Amount of carbohydrate present in 100 mg of sample = �����������
������������������ X 100
Page 67
3.6.10 Estimation of pH in milk:
3.6.10.1 Apparatus:
pH meter , conical flask
3.6.10.2 Procedure:
50 ml of milk sample was placed in a 100 ml beaker.
warmed upto 20°C. The electrode of pH meter is dipped into the milk then record
the PH of milk.
3.6.11 Estimation of pH in milk powder:
3.7.1.1 Procedure:
A 10% solution of sample
sample in distilled water and making final volume to 100
of milk powder by using digital pH meter
Estimation of pH in milk:
conical flask
50 ml of milk sample was placed in a 100 ml beaker. Milk sample was
. The electrode of pH meter is dipped into the milk then record
Estimation of pH in milk powder:
10% solution of sample was prepared by dissolving 10g of milk powder
sample in distilled water and making final volume to 100 ml. Then
of milk powder by using digital pH meter (Plate 3.8).
Plate 3.8 Digital pH meter
Milk sample was
. The electrode of pH meter is dipped into the milk then record
by dissolving 10g of milk powder
Then determined pH
Page 68
CHAPTER-IV
RESULTS AND DISCUSSION
This chapter deals with the ancillary findings of research work with due
interpretation. The effect of various compositional and processing parameters,
important observations, outcome of adopted methodology and above all product
techno – economic feasibility are presented in compiled and depicted in the form
of appropriate graphs.
4.1 Proximate Analysis of peanut milk based on different methods of
preparation:
The proximate analysis of peanut milk was carried out in the laboratory of
College of Agricultural Engineering, Bapatla. The proximate composition of
peanut milk consists of moisture content, protein content, carbohydrate content, fat
content, ash content, total solids and pH values. Various treatments for peanuts
were given before peanut milk preparation and the physic-chemical characteristics
of milk were determined.
4.2 Proximate Composition of raw peanuts:
The proximate analysis of peanuts was conducted for the comparative study
of its nutritive value with the peanut milk prepared in different methods. The raw
peanuts recorded a good amount of protein (25.48%) which is good for health. The
carbohydrates which consist mainly sugars were also present which occupied the
share of nutritive value up to 17.43%. The moisture in raw peanuts was 5.25%.
The fat content in the peanuts was found to be 47.27%. The ash content present in
the peanuts was 1.84%. The nutritive value of peanuts was analysed and shown in
Fig. 4.1.
Page 69
Fig 4.1 Proximate composition of raw peanuts
4.3 Proximate Analysis of peanut milk based on traditional methods:
4.3.1 Normal soaking:
In this method, peanuts were soaked in water for 18 hours and the milk was
prepared. The moisture content of peanut milk prepared by normal soaking method
was 89.20% (wb) whereas, the moisture content of raw peanuts was 5.25% (wb).
The high moisture content in the milk compared to raw peanuts was due to soaking
and addition of water during the milk preparation. The nutritive value of peanut
milk prepared from normal soaked peanuts was analyzed and the values were
depicted in Fig 4.2. The values of proteins, carbohydrates, fat and ash in peanut
milk were 3.68%, 4.70%, 2.16% and 0.24% respectively. The corresponding
values for raw peanut were 25.48%, 17.43%, 47.27% and 1.84% respectively. It
was observed that all the quality parameters of milk were less compared to the raw
peanuts.
Fig. 4.2 Proximate composition of peanut milk (Normal soaking)
5.25
25.48
17.43
47.27
1.842.73
Moisture Content (%)
Protein (%)
Carbohydrates(%)
Fat (%)
Ash(%)
Crude fiber (%)
89.2
3.684.7 2.16 0.24
Moisture Content (%)
Protein (%)
Carbohydrates(%)
Fat (%)
Ash(%)
Page 70
4.3.2 Soaking in Sodium Bicarbonate:
In this method, peanuts were soaked in a solution consisting 1% sodium
bicarbonate in 100% water for 18 hours and then the milk was prepared. The
moisture content of peanut milk prepared in this method was 89.06% (wb)
whereas, the moisture content of raw peanuts was 5.25% (wb). The high moisture
content in the milk compared to raw peanuts was due to soaking and addition of
water during the milk preparation. The nutritive value of peanut milk prepared by
this method was analyzed and the values were depicted in Fig 4.3. The values of
proteins, carbohydrates, fat and ash in peanut milk were 3.11%, 5.58%, 1.86% and
0.26% respectively. The corresponding values for raw peanut were 25.48%,
17.43%, 47.27% and 1.84% respectively. It was observed that all the quality
parameters of milk were less compared to the raw peanuts.
Fig. 4.3 Proximate composition of peanut milk (Soaking in 1% NaHCO3)
4.3.3 Roasting:
In this treatment peanuts were roasted in a micro oven for 20 min and
soaked in water for 14 hours. The moisture content of peanut milk prepared in this
method was 89.26% (wb) whereas, the moisture content of raw peanuts was 5.25%
(wb). The high moisture content in the milk compared to raw peanuts was due to
soaking and addition of water during the milk preparation. The nutritive value of
peanut milk prepared by this method was analyzed and the values were depicted in
Fig 4.4. The values of proteins, carbohydrates, fat and ash in peanut milk were
3.23%, 3.78%, 3.53% and 0.18% respectively. The corresponding values for raw
89.06
3.115.58
1.86 0.26
Moisture Content (%)
Protein (%)
Carbohydrates(%)
Fat (%)
Ash(%)
Page 71
peanut were 25.48%, 17.43%, 47.27% and 1.84% respectively. It was observed
that all the quality parameters of milk were less compared to the raw peanuts.
Fig. 4.4 Proximate composition of peanut milk (Roasted peanuts)
4.3.4 Pressure blanching:
4.3.4.1 Pressure blanching for 0 minutes:
In this treatment peanuts were blanched under a pressure 15 psi and
temperature 121oC in an autoclave for zero minutes. The blanched peanuts were
soaked in water for 6 hours. The moisture content of peanut milk prepared in this
method was 89.45% (wb) whereas, the moisture content of raw peanuts was 5.25%
(wb). The high moisture content in the milk compared to raw peanuts was due to
blanching and addition of water during the milk preparation. The nutritive value of
peanut milk prepared by this method was analyzed and the values were depicted in
Fig 4.5. The values of proteins, carbohydrates, fat and ash in peanut milk were
3.74%, 5.02%, 1.83% and 0.18% respectively. The corresponding values for raw
peanut were 25.48%, 17.43%, 47.27% and 1.84% respectively. It was observed
that all the quality parameters of milk were less compared to the raw peanuts.
Fig. 4.5 Proximate composition of peanut milk (Pressure blanching for zero
minutes)
89.26
3.233.783.53 0.18Moisture Content (%)
Protein (%)
Carbohydrates(%)
Fat (%)
Ash(%)
89.45
3.745.02 1.83 0.18
Moisture Content (%)
Protein (%)
Carbohydrates(%)
Fat (%)
Ash(%)
Page 72
4.3.4.2 Pressure blanching for 2 minutes:
In this treatment peanuts were blanched under a pressure 15 psi and
temperature 121oC in an autoclave for 2 minutes. The blanched peanuts were
soaked in water for 6 hours. The moisture content of peanut milk prepared in this
method was 89.25% (wb) whereas, the moisture content of raw peanuts was 5.25%
(wb). The high moisture content in the milk compared to raw peanuts was due to
blanching and addition of water during the milk preparation. The nutritive value of
peanut milk prepared by this method was analyzed and the values were depicted in
Fig 4.6. The values of proteins, carbohydrates, fat and ash in peanut milk were
3.51%, 5.05%, 1.76% and 0.19% respectively. The corresponding values for raw
peanut were 25.48%, 17.43%, 47.27% and 1.84% respectively. It was observed
that all the quality parameters of milk were less compared to the raw peanuts.
Fig. 4.6 Proximate composition of peanut milk (Pressure blanching for 2
minutes)
4.3.4.3 Pressure blanching for 3 minutes:
In this treatment peanuts were blanched under a pressure 15 psi and
temperature 121oC in an autoclave for 3 minutes. The blanched peanuts were
soaked in water for 6 hours. The moisture content of peanut milk prepared in this
method was 90.28% (wb) whereas, the moisture content of raw peanuts was 5.25%
(wb). The high moisture content in the milk compared to raw peanuts was due to
blanching and addition of water during the milk preparation. The nutritive value of
peanut milk prepared by this method was analyzed and the values were depicted in
Fig 4.7. The values of proteins, carbohydrates, fat and ash in peanut milk were
3.34%, 4.58%, 1.63% and 0.15% respectively. The corresponding values for raw
89.25
3.515.05 1.76 0.19
Moisture Content (%)
Protein (%)
Carbohydrates(%)
Fat (%)
Ash(%)
Page 73
peanut were 25.48%, 17.43%, 47.27% and 1.84% respectively. It was observed
that all the quality parameters of milk were less compared to the raw peanuts.
Fig. 4.7 Proximate composition of peanut milk (Pressure blanching for 3
minutes)
4.3.4.4 Pressure blanching for 5 minutes:
In this treatment peanuts were blanched under a pressure 15 psi and
temperature 121oC in an autoclave for 5 minutes. The blanched peanuts were
soaked in water for 6 hours. The moisture content of peanut milk prepared in this
method was 89.35% (wb) whereas, the moisture content of raw peanuts was 5.25%
(wb). The high moisture content in the milk compared to raw peanuts was due to
blanching and addition of water during the milk preparation. The nutritive value of
peanut milk prepared by this method was analyzed and the values were depicted in
Fig 4.8. The values of proteins, carbohydrates, fat and ash in peanut milk were
3.40%, 5.33%, 1.76% and 0.15% respectively. The corresponding values for raw
peanut were 25.48%, 17.43%, 47.27% and 1.84% respectively. It was observed
that all the quality parameters of milk were less compared to the raw peanuts.
Fig. 4.8 Proximate composition of peanut milk (Pressure blanching for 5
minutes)
90.28
3.344.581.63 0.15
Moisture Content (%)
Protein (%)
Carbohydrates(%)
Fat (%)
Ash(%)
89.35
3.45.33 1.76 0.15Moisture Content (%)
Protein (%)
Carbohydrates(%)
Fat (%)
Ash(%)
Page 74
4.4 Comparison of the proximate composition of peanut milk prepared by
different methods:
The proximate composition of the peanut milk prepared by the different
methods was compared to study the effect of process parameters on milk
quality.
4.4.1 Moisture content:
The moisture contents of peanut milk prepared from different methods
were calculated. Among the four methods (Normal soaking, soaking in 1%
NaHCO3, roasting and pressure blanching), the peanut milk sample prepared from
pressure blanching for 3 minutes recorded the highest moisture of 90.28 (%wb)
and sample soaked in sodium bicarbonate recorded the lowest moisture of 89.06
(%wb). The moisture contents of the remaining samples were 89.45, 89.35, 89.26,
89.25 and 89.20 (%wb) in pressure blanching for 0 minutes, 5 minutes, roasting,
pressure blanching for 2 minutes and normal soaking respectively (Fig 4.9). The
observed highest value of moisture in pressure blanching than the rest of the
methods might be due higher penetration of water molecules during blanching and
soaking after blanching.
Fig. 4.9 Moisture contents of peanut milk prepared in different conditions
89.2089.06
89.2689.45
89.25
90.28
89.35
88.4088.6088.8089.0089.2089.4089.6089.8090.0090.2090.40
No
rmal
So
akin
g
Sod
ium
b
icar
bo
nat
e
Ro
asti
ng
0 m
inP
ress
ure
b
lan
chin
g
2 m
in
3 m
in
5 m
in
Mo
istu
re C
on
ten
t (
% w
b)
Treatment methods of peanut milk
Page 75
4.4.2 Protein Content:
The protein contents of peanut milk prepared from different methods were
calculated. Among the four methods, the peanut milk sample prepared from
peanuts pressure blanched for 2 minutes recorded the highest protein content of
3.74 % and sample soaking in sodium bicarbonate recorded the lowest protein
content of 3.11 %. The protein contents of the remaining samples were 3.68, 3.51,
3.40, 3.34, 3.23 and 3.11% in normal soaking, pressure blanched for zero minutes,
5 minutes, 3 minutes, and roasting respectively (Fig 4.10). Soaking in normal
water breaks down the phytic acid and helps in bioactivity of proteins. During
pressure blanching, higher moisture penetration had taken place due to soaking
after blanching.
Fig. 4.10 Protein contents of peanut milk prepared by different methods
4.4.3 Fat Content:
The fat contents of peanut milk prepared from different methods were
calculated. Among the four methods, the peanut milk sample prepared from
peanuts roasted for 20 min and soaked for 14 hours recorded the highest fat content
of 3.53 % and sample pressure blanched for 3 minutes recorded the lowest fat
content of 1.63 %. The fat contents of the remaining samples were 2.16, 1.86, 1.83,
1.76 and 1.76% in normal soaking, sodium bicarbonate and pressure blanching at 0
minutes, 2 minutes, and 5 minutes, respectively (Fig 4.11).
3.68
3.11 3.233.51 3.74
3.34 3.40
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
No
rmal
So
akin
g
Sod
ium
b
icar
bo
na
te
Ro
asti
ng
0 m
inP
ress
ure
b
lan
chin
g
2 m
in
3 m
in
5 m
in
pro
tein
Co
nte
nt
( %
)
Treatment methods of peanut milk
Page 76
Fig. 4.11 Fat contents of peanut milk prepared by different methods
4.4.4 Carbohydrates content:
The carbohydrates contents of peanut milk prepared from different methods
were calculated. Among the four methods, the peanut milk sample prepared from
peanuts soaking 1% sodium bicarbonate recorded the highest carbohydrates
content of 5.58 % and sample roasting recorded the lowest carbohydrates content
of 3.78 %. The carbohydrates contents of the remaining samples were 5.33, 5.05,
5.02, 4.70, and 4.58% in pressure blanching for 5 minutes, 2 minutes, 0 minutes,
normal soaking, and pressure blanching for 3 minutes and roasting respectively
(Fig 4.12). The increase in carbohydrates content is due to reaction of bicarbonate
molecule with polysaccharide which permitted higher enzymatic digestion of
amylases.
Fig. 4.12 Carbohydrate contents of peanut milk prepared by different
methods
2.161.86
3.53
1.83 1.76 1.63 1.76
0.000.501.001.502.002.503.003.504.00
No
rmal
So
akin
g
Sod
ium
b
icar
bo
nat
e
Ro
asti
ng
0 m
inP
ress
ure
b
lan
chin
g
2 m
in
3 m
in
5 m
in
Fat
( %
)
Treatment methods of peanut milk
4.705.58
3.78
5.02 5.054.58
5.33
0.00
1.00
2.00
3.00
4.00
5.00
6.00
Normal Soaking Sodium bicarbonateRoasting 0 minPressure blanching
2 min 3 min 5 min
Car
bo
hyd
rate
s (
% )
Treatment methods of peanut milk
Page 77
4.4.5 Ash Content:
The ash contents of peanut milk prepared from different methods were
calculated. Among the four treatments, the peanut milk sample prepared from
peanuts soaking in sodium bicarbonate recorded the highest ash content of 0.26 %
and sample pressure blanching for 3 minutes and 5 minutes recorded the lowest ash
content of 0.15 %. The ash contents of the remaining samples were 0.24, 0.19, 0.18
and 0.18, in normal soaking, pressure blanching at 2 minutes, 0 minutes and
roasting respectively (Fig 4.13).
Fig. 4.13 Ash contents of peanut milk prepared by different methods
4.4.6 pH Value:
The pH values of peanut milk prepared from different methods were
calculated. Among the four methods, the peanut milk sample prepared from
peanuts soaking in sodium bicarbonate recorded the highest pH value of 6.33 and
sample pressure blanching for 5 minutes recorded the lowest pH value of 5.47. The
pH values of the remaining samples were 6.14, 6.06, 5.73, 5.66 and 5.57 in normal
soaking, roasting and pressure blanching at 0 minutes, 2 minutes and 3 minutes
respectively (Fig 4.14). One of the main reason to use sodium bicarbonate is to
trigger a reaction with the acid in the peanuts. A hydrogen ion from peanut reacts
with the bicarbonate ion. Carbon dioxide is released thus expanding peanuts.
0.240.26
0.18 0.18 0.19
0.15 0.15
0.00
0.05
0.10
0.15
0.20
0.25
0.30
Normal Soaking
Sodium bicarbonate
Roasting 0 minPressure blanching
2 min 3 min 5 min
Ash
Co
nte
nt
( %
)
Treatment methods of peanut milk
Page 78
Fig. 4.14 pH contents of peanut milk prepared by different methods
4.4.7 Total Solids:
The total solids of peanut milk prepared from different methods were
calculated. Among the four methods, the peanut milk sample prepared from
peanuts soaking in sodium bicarbonate recorded the highest total solids of 11.00%
and sample pressure blanching for 3 minutes recorded the lowest total solids of
9.71 %. The total solids of the remaining samples were 10.8, 10.75, 10.73, 10.65,
and 10.55% in normal soaking, pressure blanching for 2 minutes, roasting, pressure
blanching for 5 minutes and 0 minutes respectively (Fig 4.15).
Fig. 4.15 Total solids of peanut milk prepared by different methods
6.146.33
6.06
5.735.66
5.575.47
5.00
5.20
5.40
5.60
5.80
6.00
6.20
6.40
No
rmal
So
akin
g
Sod
ium
b
icar
bo
nat
e
Ro
asti
ng
0 m
inP
ress
ure
b
lan
chin
g
2 m
in
3 m
in
5 m
in
pH
Treatment methods of peanut milk
10.8011.00
10.7310.55
10.75
9.71
10.65
9.00
9.50
10.00
10.50
11.00
11.50
Normal Soaking
Sodium bicarbonate
Roasting 0 minPressure
blanching
2 min 3 min 5 min
Tota
l So
lids
Treatment methods of peanut milk
Page 79
4.5 Preparation of peanut milk powder using spray dryer technique:
The spray drying process was carried out in Post Harvest Technology
Centre, Bapatla using spray dryer S.M. Science Tech., India. The spray dryer
works on the principle of co-current flow atomization. Spray dryer consisted of
feed pump, atomizer, air heater, air disperser, drying chamber, and systems for
exhaust air cleaning and powder recovery. The maximum capacity of the spray
dryer was 1.30 l/h with the nozzle fits to 1 mm size. The peanut milk was fed in to
the drying chamber with feed flow rate of 20 ml/min and inlet air temperature was
maintained at 130°C temperature. The obtained powder was stored in LDPE covers
under ambient conditions. It was observed that for 100 ml of peanut milk sample
the amount of peanut milk powder collected was 8 grams.
4.6 Proximate Analysis of peanut milk powder based on different methods of
preparation:
The proximate analysis of peanut milk powder was carried out in the
laboratory of college of Agricultural Engineering, Bapatla. The proximate analysis
of peanut milk powder consists of moisture content, protein content, carbohydrate
content, fat content, crude fiber, ash content, total solids and pH values. Peanut
milk was prepared by different methods and peanut milk powder was prepared by
spray drying technique and their nutritive values were studied.
4.7 Proximate Analysis of peanut milk powder based on traditional methods:
4.7.1 Normal soaking:
The moisture content of peanut milk powder prepared by normal soaking
method was 4.84% (wb) whereas, the moisture content of milk was 89.20% (wb).
The high amount of moisture present in the milk was evaporated during the spray
drying process and resulted in low moisture powder. The nutritive value of peanut
milk powder prepared from normal soaked peanuts was analyzed and the values
were depicted in Fig 4.16. The values of proteins, carbohydrates, fat, ash and crude
fiber in peanut milk powder were 27.05%, 18.22%, 45.89%, 2.86% and 1.11%
respectively. It was observed that all the quality parameters namely proteins,
Page 80
carbohydrates, fat and ash increased when the milk was converted into powder by
spray drying.
Fig. 4.16 Proximate composition of peanut milk powder (Normal soaking)
4.7.2 Soaking in Sodium Bicarbonate:
The moisture content of peanut milk powder prepared by soaking in sodium
bicarbonate method was 5.30% (wb) whereas, the moisture content of milk was
89.06% (wb). The high amount of moisture present in the milk was evaporated
during the spray drying process and resulted in low moisture powder. The nutritive
value of peanut milk powder prepared from this method was analyzed and the
values were depicted in Fig 4.17. The values of proteins, carbohydrates, fat, ash
and crude fiber in peanut milk powder were 29.97%, 18.79%, 42.18%, 2.45% and
1.31% respectively. It was observed that all the quality parameters namely
proteins, carbohydrates, fat and ash increased when the milk was converted into
powder by spray drying.
Fig. 4.17 Proximate composition of peanut milk powder (Soaking in 1%
NaHCO3)
4.84
27.05
18.22
45.89
2.86 1.11
Moisture Content (%)
Protein (%)
Carbohydrates(%)
Fat (%)
Ash(%)
Crude fiber (%)
5.3
29.97
18.79
42.18
2.45 1.31
Moisture Content (%)
Protein (%)
Carbohydrates(%)
Fat (%)
Ash(%)
Crude fiber (%)
Page 81
4.7.3 Roasting:
The moisture content of peanut milk powder prepared by roasting method
was 5.43% (wb) whereas, the moisture content of milk was 89.26% (wb). The high
amount of moisture present in the milk was evaporated during the spray drying
process and resulted in low moisture powder. The nutritive value of peanut milk
powder prepared from normal soaked peanuts was analyzed and the values were
depicted in Fig 4.18. The values of proteins, carbohydrates, fat, ash and crude fiber
in peanut milk powder were 27.44%, 15.25%, 48.35%, 2.12% and 1.26%
respectively. It was observed that all the quality parameters namely proteins,
carbohydrates, fat and ash increased when the milk was converted into powder by
spray drying.
Fig. 4.18 Proximate composition of peanut milk powder (roasting)
4.7.4 Pressure blanching:
4.7.4.1 Pressure blanching for 0 minutes:
. The moisture content of peanut milk powder prepared by pressure
blanching for zero minutes method was 4.51% (wb) whereas, the moisture content
of milk was 89.45% (wb). The high amount of moisture present in the milk was
evaporated during the spray drying process and resulted in low moisture powder.
The nutritive value of peanut milk powder prepared from this method was
analyzed and the values were depicted in Fig 4.19. The values of proteins,
carbohydrates, fat, ash and crude fiber in peanut milk powder were 30.88%,
19.72%, 40.89%, 2.49% and 1.56% respectively. It was observed that all the
5.43
27.44
15.25
48.35
2.12 1.26
Moisture Content (%)
Protein (%)
Carbohydrates(%)
Fat (%)
Ash(%)
Crude fiber (%)
Page 82
quality parameters namely proteins, carbohydrates, fat and ash increased when the
milk was converted into powder by spray drying.
Fig. 4.19 Proximate composition of peanut milk powder (Pressure blanching
for zero minutes)
4.7.4.2 Pressure blanching for 2 minutes:
The moisture content of peanut milk powder prepared by pressure
blanching for 2 minutes was 6.53% (wb) whereas, the moisture content of milk
was 89.25% (wb). The high amount of moisture present in the milk was evaporated
during the spray drying process and resulted in low moisture powder. The nutritive
value of peanut milk powder prepared from this method was analyzed and the
values were depicted in Fig 4.20. The values of proteins, carbohydrates, fat, ash
and crude fiber in peanut milk powder were 28.25%, 14.61%, 46.94%, 2.28% and
2.07% respectively. It was observed that all the quality parameters namely
proteins, carbohydrates, fat and ash increased when the milk was converted into
powder by spray drying.
Fig. 4.20 Proximate composition of peanut milk powder (Pressure blanching
for 2 minutes)
4.51
30.88
19.72
40.89
2.49 1.56Moisture Content (%)
Protein (%)
Carbohydrates(%)
Fat (%)
Ash(%)
Crude fiber (%)
6.53
28.25
14.61
46.94
2.28 2.07Moisture Content (%)
Protein (%)
Carbohydrates(%)
Fat (%)
Ash(%)
Crude fiber (%)
Page 83
4.7.4.3 Pressure blanching for 3 minutes:
The moisture content of peanut milk powder prepared by pressure
blanching for 3 minutes was 5.65% (wb) whereas, the moisture content of milk
was 90.28% (wb). The high amount of moisture present in the milk was evaporated
during the spray drying process and resulted in low moisture powder. The nutritive
value of peanut milk powder prepared from this method was analyzed and the
values were depicted in Fig 4.21. The values of proteins, carbohydrates, fat, ash
and crude fiber in peanut milk powder were 28.25%, 18.87%, 44.03%, 1.86% and
1.34% respectively. It was observed that all the quality parameters namely
proteins, carbohydrates, fat and ash increased when the milk was converted into
powder by spray drying.
Fig. 4.21 Proximate composition of peanut milk powder (Pressure blanching
for 3 minutes)
4.7.4.4 Pressure blanching for 5 minutes:
The moisture content of peanut milk powder prepared by pressure
blanching for 5 minutes was 5.29% (wb) whereas, the moisture content of milk
was 89.35% (wb). The high amount of moisture present in the milk was evaporated
during the spray drying process and resulted in low moisture powder. The nutritive
value of peanut milk powder prepared from this method was analyzed and the
values were depicted in Fig 4.22. The values of proteins, carbohydrates, fat, ash
and crude fiber in peanut milk powder were 28.70%, 19.51%, 43.19%, 1.77% and
1.53% respectively. It was observed that all the quality parameters namely
proteins, carbohydrates, fat and ash increased when the milk was converted into
powder by spray drying.
5.65
28.25
18.87
44.03
1.86 1.34
Moisture Content (%)
Protein (%)
Carbohydrates(%)
Fat (%)
Ash(%)
Crude fiber (%)
Page 84
Fig. 4.22 Proximate composition of peanut milk powder (Pressure blanching
for 5 minutes)
4.8 Comparison of the proximate composition of peanut milk powder by
different methods:
The proximate composition of the peanut milk powder prepared by the
different methods was compared to study the effect of process parameters on milk
powder quality.
4.8.1 Moisture content:
The moisture contents of peanut milk powder prepared from different
methods were calculated. Among the four methods, the sample pressure blanched
for 2 minutes recorded the highest moisture of 6.53 (%wb) and the sample pressure
blanched for zero minutes recorded the lowest moisture of 4.51(%wb). The
moisture contents of the remaining samples were 5.65%, 5.43%, 5.30%, 5.29% and
4.84% in pressure blanched for 3 min, roasting, soaking in sodium bicarbonate,
pressure blanched for 5 min and normal soaking respectively (Fig 4.23). The
observed highest value of moisture in pressure blanching than the rest of the
methods might be due higher penetration of water molecules during blanching and
soaking after blanching.
5.29
28.7
19.51
43.19
1.77 1.53Moisture Content (%)
Protein (%)
Carbohydrates(%)
Fat (%)
Ash(%)
Crude fiber (%)
Page 85
Fig. 4.23 Moisture contents of peanut milk powder prepared by different
methods
4.8.2 Protein content:
The protein contents of peanut milk powder prepared from different
methods were calculated. Among the four methods, the sample pressure blanched
for 0 minutes recorded the highest protein content of 30.88 % and the sample
normal soaking recorded the lowest protein content of 27.05 %. The protein
contents of the remaining samples were 29.97%, 28.70%, 28.25%, 28.25%, and
27.44% in soaking in sodium bicarbonate, pressure blanched for 5 minutes, 2
minutes, 3 minutes, and roasting respectively (Fig 4.24).
Fig. 4.24 Protein contents of peanut milk powder prepared by different
methods
4.845.30 5.43
4.51
6.535.65
5.29
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
No
rmal
So
akin
g
Sod
ium
b
icar
bo
nat
e
Ro
asti
ng
0 m
inP
ress
ure
b
lan
chin
g
2 m
in
3 m
in
5 m
in
Mo
istu
re C
on
ten
t (
%w
b )
Treatment methods of peanut milk powder
27.05
29.97
27.44
30.88
28.25 28.2528.70
25.00
26.00
27.00
28.00
29.00
30.00
31.00
32.00
No
rmal
So
akin
g
Sod
ium
b
icar
bo
nat
e
Ro
asti
ng
0 m
inP
ress
ure
b
lan
chin
g
2 m
in
3 m
in
5 m
in
Pro
tein
( %
)
Treatment methods of peanut milk powder
Page 86
4.8.3 Fat content:
The fat contents of peanut milk powder prepared from different methods
were calculated. Among the four methods, the sample roasted for 20 minutes
recorded the highest fat content of 48.35% and pressure blanched for 0 min
recorded the lowest fat content of 40.89 %. The protein contents of the remaining
samples were 46.94%, 45.89%, 44.63%, 43.19% and 42.18%, in pressure blanched
for 2 minutes, normal soaking, pressure blanched for 3 minutes, 5 minutes and
soaking sodium bicarbonate respectively (Fig 4.25).
Fig. 4.25 Fat contents of peanut milk powder prepared by different methods
4.8.4 Carbohydrate content:
The carbohydrates contents of peanut milk powder prepared from different
methods were calculated. Among the four methods, the sample pressure blanched
for 0 minutes recorded the highest carbohydrate content of 19.72% and pressure
blanched for 2 minutes recorded the lowest carbohydrate content of 14.61%. The
carbohydrates contents of the remaining samples were 19.51, 18.87, 18.79, 18.22
and 15.25 in pressure blanching for 5 minutes, 3 minutes, soaking in sodium
bicarbonate, normal soaking and roasting respectively (Fig 4.26).
45.89
42.18
48.35
40.89
46.94
44.6343.19
36.00
38.00
40.00
42.00
44.00
46.00
48.00
50.00
No
rmal
So
akin
g
Sod
ium
b
icar
bo
nat
e
Ro
asti
ng
0 m
inP
ress
ure
b
lan
chin
g
2 m
in
3 m
in
5 m
in
Fat
( %
)
Treatment methods of peanut milk powder
Page 87
Fig. 4.26 Carbohydrates contents of peanut milk powder prepared by
different methods
4.8.5 Crude fiber content:
The crude fiber contents of peanut milk powder prepared from different
methods were calculated. Among the four methods, the sample pressure blanched
for 2 minutes recorded the highest crude fiber content of 2.07 % and normal
soaking recorded the lowest crude fiber content of 1.11 %. The crude fiber contents
of the remaining samples were 1.56, 1.53, 1.34, 1.31 and 1.26% in pressure
blanching for 0 minutes, 5 minutes, 3 minutes and soaking in sodium bicarbonate
respectively (Fig 4.27).
Fig. 4.27 Crude fiber contents of peanut milk powder prepared by different
methods
18.22 18.79
15.25
19.72
14.61
18.87 19.51
0.00
5.00
10.00
15.00
20.00
25.00
No
rmal
So
akin
g
Sod
ium
b
icar
bo
nat
e
Ro
asti
ng
0 m
inP
ress
ure
b
lan
chin
g
2 m
in
3 m
in
5 m
in
Car
bo
hyd
rate
s (
% )
Treatment methods of peanut milk powder
1.111.31 1.26
1.56
2.07
1.341.53
0.00
0.50
1.00
1.50
2.00
2.50
No
rmal
So
akin
g
Sod
ium
b
icar
bo
nat
e
Ro
asti
ng
0 m
inP
ress
ure
b
lan
chin
g
2 m
in
3 m
in
5 m
in
Cru
de
fib
er
( %
)
Treatment methods of peanut milk powder
Page 88
4.8.6 Ash content:
The ash contents of peanut milk powder prepared from different methods
were calculated. Among the four methods, the sample treated with normal soaking
recorded the highest ash content of 2.86 % and pressure blanched for 5 minutes
recorded the lowest ash content of 1.77 %. The ash contents of the remaining
samples were 2.49, 2.45, 2.28, 2.12 and 1.86 in pressure blanching for 0 minutes,
soaking in sodium bicarbonate, pressure blanching for 2 minutes, roasting, and
pressure blanching for 3 minutes respectively (Fig 4.28).
Fig. 4.28 Ash contents of peanut milk powder prepared by different methods
4.8.7 Total solids:
The total solids of peanut milk powder prepared from different methods
were calculated. Among the four methods, the sample pressure blanched for 0
minutes recorded the highest total solids of 95.49% and the sample pressure
blanched for 2 minutes lowest total solids of 93.57 %. The total solids of the
remaining samples were 95.16, 94.70, 94.70, 94.57 and 94.35% in normal soaking,
pressure blanching for 5 minutes, soaking in sodium bicarbonate, roasting, and
pressure blanching for 3 minutes respectively (Fig 4.29).
2.862.45
2.122.49
2.281.86 1.77
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
No
rmal
So
akin
g
Sod
ium
b
icar
bo
nat
e
Ro
asti
ng
0 m
inP
ress
ure
b
lan
chin
g
2 m
in
3 m
in
5 m
in
Ash
( %
)
Treatment methods of peanut milk powder
Page 89
Fig: 4.29 Total solids of peanut milk powder prepared by different methods
4.8.8 pH value:
The pH values of peanut milk powder prepared from different methods
were calculated. Among the four methods, the sample treated soaking in sodium
bicarbonate recorded the highest pH value of 6.33 and the sample pressure
blanching for 5 minutes recorded the lowest Ph value of 5.47. The pH contents of
the remaining samples were 6.14, 6.06, 5.73, 5.66 and 5.57 in normal soaking,
roasting and pressure blanching for 0 minutes, 2 minutes and 3 minutes
respectively (Fig 4.30).
Fig: 4.30 pH values of peanut milk powder prepared by different methods
95.16
94.70 94.57
95.49
93.57
94.3594.70
92.50
93.00
93.50
94.00
94.50
95.00
95.50
96.00
No
rmal
So
akin
g
Sod
ium
b
icar
bo
nat
e
Ro
asti
ng
0 m
inP
ress
ure
b
lan
chin
g
2 m
in
3 m
in
5 m
in
Tota
l So
lids
( %
)
Treatment methods of peanut milk powder
6.146.33
6.06
5.735.66
5.575.47
5.00
5.20
5.40
5.60
5.80
6.00
6.20
6.40
No
rmal
So
akin
g
Sod
ium
b
icar
bo
nat
e
Ro
asti
ng
0 m
inP
ress
ure
b
lan
chin
g
2 m
in
3 m
in
5 m
in
pH
Treatment methods of Peanut milk powder
Page 90
4.9 Comparison between peanut milk and milk powder:
The proximate composition of the peanut milk and powder prepared by
different methods was compared to study the effect of process parameters on milk
and powder quality.
4.9.1 Normal soaking:
The protein, carbohydrate and fat contents of peanut milk powder were
considerably higher than those of the peanut milk i.e. 3.68 and 27.05; 4.70 and
18.22; 2.16 and 45.89% respectively (Fig 4.31). The moisture content in peanut
milk (89.20%wb) was higher than the moisture content (4.84%wb) in peanut milk
powder. The total solids in peanut milk powder (95.16%) were also higher than the
total solids in peanut milk (10.80%). However, the pH value remained same in
both peanut milk and milk powder as 6.14. The ash content (2.86%) and crude
fibre (1.11%) were also reported to be higher for peanut milk powder than peanut
milk.
Fig: 4.31 Proximate composition of peanut milk and powder by normal
soaking method
89.20
3.68 4.70 2.16 0.24 0.00
10.806.144.84
27.0518.22
45.89
2.86 1.11
95.16
6.14
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
100.00
Normal Soaking Peanut milk
Normal Soaking Peanut Milk powder
Page 91
4.9.2 Soaking in sodium bicarbonate:
The protein, carbohydrate and fat contents of peanut milk powder were
considerably higher than those of the peanut milk i.e. 3.11 and 29.97; 5.58 and
18.79; 1.86 and 42.18% respectively (Fig 4.32). The moisture content in peanut
milk (89.00%wb) was higher than the moisture content (5.30%) in peanut milk
powder (5.30%). The total solids in peanut milk powder (94.70%) were also higher
than peanut milk (11.00%). However, the pH value remained same in both peanut
milk and peanut milk powder as 6.33. The ash content (2.45%) and crude fibre
(1.31%) were also reported to be higher for peanut milk powder than peanut milk.
Fig: 4.32 Proximate composition of peanut milk and powder 1% NaHCO3
method
4.9.3 Roasting:
The protein, carbohydrate and fat contents of peanut milk powder were
considerably higher than those of the peanut milk i.e. 3.23 and 27.44; 3.78 and
15.25; 3.53 and 48.35% respectively (Fig 4.33). The moisture content in peanut
milk (89.26%wb) was higher than the moisture content (5.43%wb) in peanut milk
powder. The total solids in peanut milk powder (94.57%) were also higher than
peanut milk (10.73%). However, the pH value remained same in both peanut milk
89.00
3.11 5.58 1.86 0.26 0.00
11.006.335.30
29.97
18.79
42.18
2.45 1.31
94.70
6.33
0.0010.0020.0030.0040.0050.0060.0070.0080.0090.00
100.00
Sodium Bicarbonate Peanut milk
Sodium Bicarbonate Peanut Milk powder
Page 92
and peanut milk powder as 6.06. The ash content (2.12%) and crude fibre (1.26%)
were also reported to be higher for peanut milk powder than peanut milk.
Fig: 4.33 Proximate composition of peanut milk and powder by roasting
method
4.9.4 Pressure blanching:
4.9.4.1 Pressure blanching for 0 minutes:
The protein, carbohydrate and fat contents of peanut milk powder were
considerably higher than those of the peanut milk i.e. 3.51 and 30.88; 5.02 and
19.72; 1.83 and 40.89% respectively (Fig 4.34). The moisture content in peanut
milk (89.45%wb) was higher than moisture content in peanut milk powder
(4.51%wb). The total solids in peanut milk powder (95.49%) were also higher than
peanut milk (10.55%). However, the pH value remained same in both peanut milk
and peanut milk powder as 5.73. The ash content (2.49%) and crude fibre (1.56%)
were also reported to be higher for peanut milk powder than peanut milk.
89.26
3.23 3.78 3.53 0.18 0.00
10.736.065.43
27.44
15.25
48.35
2.12
1.26
94.57
6.06
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
100.00
Roasting Peanut milk
Roasting Peanut Milk powder
Page 93
Fig: 4.34 Proximate composition of peanut milk and powder by pressure
blanching for zero minutes method
4.9.4.2 Pressure blanching for 2 minutes:
The protein, carbohydrate and fat contents of peanut milk powder were
considerably higher than those of the peanut milk i.e. 3.74 and 28.25; 5.05 and
14.61; 1.76 and 46.94% respectively (Fig 4.35). The moisture content in peanut
milk (89.25%wb) was higher than moisture content in peanut milk powder
(6.53%wb). The total solids in peanut milk powder (93.57%) were also higher than
peanut milk (10.75%). However, the pH value remained same in both peanut milk
and peanut milk powder as 5.66. The ash content (2.28%) and crude fibre (2.07%)
were also reported to be higher for peanut milk powder than peanut milk.
89.45
3.51 5.02 1.83 0.18 0.0010.55
5.734.51
30.88
19.72
40.89
2.491.56
95.49
5.73
0.00
20.00
40.00
60.00
80.00
100.00
120.00
Pressure blanching (0 min) Peanut milk
Page 94
Fig: 4.35 Proximate composition of peanut milk and powder by pressure
blanching for 2 minutes method
4.9.4.3 Pressure blanching for 3 minutes:
The protein, carbohydrate and fat contents of peanut milk powder were
considerably higher than those of the peanut milk i.e. 3.34 and 28.25; 4.58 and
18.87; 1.63 and 44.03% respectively (Fig 4.36). The moisture content in peanut
milk (90.28%wb) was higher than moisture content in peanut milk powder
(5.65%wb). The total solids in peanut milk powder (94.35%) were also higher than
peanut milk (9.71%). However, the pH value remained same in both peanut milk
and peanut milk powder as 5.57. The ash content (1.86%) and crude fibre (1.34%)
were also reported to be higher for peanut milk powder than peanut milk.
89.25
3.74 5.05 1.76 0.19 0.0010.75
5.666.53
28.25
14.61
46.94
2.28 2.07
93.57
5.66
0.0010.0020.0030.0040.0050.0060.0070.0080.0090.00
100.00
Pressure blanching (2 min) Peanut milk
Pressure blanching (2 min) Peanut Milk powder
Page 95
Fig: 4.36 Proximate composition of peanut milk and powder by pressure
blanching for 3 minutes method
4.9.4.4 Pressure blanching for 5 minutes:
The protein, carbohydrate and fat contents of peanut milk powder were
considerably higher than those of the peanut milk i.e. 3.40 and 28.70; 5.33 and
19.51; 2.16 and 45.89% respectively (Fig 4.37). The moisture content in peanut
milk (89.35%wb) was higher than moisture content in peanut milk powder
(5.29%wb). The total solids in peanut milk powder (94.70%) were also higher than
peanut milk (10.65%). However, the pH value remained same in both peanut milk
and peanut milk powder as 5.47. The ash content (1.77%) and crude fibre (1.53%)
were also reported to be higher for peanut milk powder than peanut milk. On
comparison between peanut milk and peanut milk powder, it was noticed that
nutritionally peanut milk powder was good.
90.28
3.34 4.58 1.63 0.15 0.009.71 5.575.65
28.2518.87
44.03
1.86 1.34
94.35
5.57
0.0010.0020.0030.0040.0050.0060.0070.0080.0090.00
100.00
Pressure blanching (3 min) Peanut milkPressure blanching (3 min) Peanut Milk powder
Page 96
Fig: 4.37 Proximate composition of peanut milk and powder by pressure
blanching for 5 minutes method
89.35
3.40 5.33 1.76 0.15 0.0010.65
5.475.29
28.7019.51
43.19
1.77 1.53
94.70
5.47
0.0010.0020.0030.0040.0050.0060.0070.0080.0090.00
100.00
Pressure blanching (5 min) Peanut milk
Pressure blanching (5 min) Peanut Milk powder
Page 97
Comparison among proximate composition parameters of peanut milk:
89
.20
3.6
8
4.7
0
2.1
6
0.2
4
0.0
0
10
.80
6.1
4
89
.06
3.1
1
5.5
8
1.8
6
0.2
6
0.0
0
11
.00
6.3
3
89
.26
3.2
3
3.7
8
3.5
3
0.1
8
0.0
0
10
.73
6.0
6
89
.45
3.5
1
5.0
2
1.8
3
0.1
8
0.0
0
10
.55
5.7
3
89
.25
3.7
4
5.0
5
1.7
6
0.1
9
0.0
0
10
.75
5.6
6
90
.28
3.3
4
4.5
8
1.6
3
0.1
5
0.0
0
9.7
1
5.5
7
89
.35
3.4
0
5.3
3
1.7
6
0.1
5
0.0
0
10
.65
5.4
7
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
100.00
Peanut milk Normal soaking
Peanut milk Sodium Bicarbonate
Peanut milk Roasting
Peanut milk Pressure blanching 0 min
Peanut milk Pressure blanching 2 min
Peanut milk Pressure blanching 3 min
Peanut milk Pressure blanching 5 min
Page 98
Fig. 4.38 Comparison among proximate composition parameters of peanut milk using different methods
Comparison among proximate composition parameters of peanut milk powder:
Fig. 4.39 Comparison among proximate composition parameters of peanut milk powder using different methods
4.8
4
27
.05
18
.22
45
.89
2.8
6
1.1
1
95
.16
6.1
4
5.3
0
29
.97
18
.79
42
.18
2.4
5
1.3
1
94
.70
6.3
3
5.4
3
27
.44
15
.25
48
.35
2.1
2
1.2
6
94
.57
6.0
6
4.5
1
30
.88
19
.72
40
.89
2.4
9
1.5
6
95
.49
5.7
3
6.5
3
28
.25
14
.61
46
.94
2.2
8
2.0
7
93
.57
5.6
6
5.6
5
28
.25
18
.87
44
.63
1.8
6
1.3
4
94
.35
5.5
7
5.2
9
28
.70
19
.51
43
.19
1.7
7
1.5
3
94
.70
5.4
7
0.00
20.00
40.00
60.00
80.00
100.00
120.00
Peanut milk powder Normal soaking
Peanut milk powder Sodium BicarbonatePeanut milk powder Roasting
Peanut milk powder Pressure blanching 0 minPeanut milk powder Pressure blanching 2 minPeanut milk powder Pressure blanching 3 min
Page 99
CHAPTER-V
SUMMARY AND CONCLUSIONS
Peanuts are good food for infants suffering from various forms of
malnutrition and for individual with lactose intolerance allergies. Peanut milk does
not contain any lactose and is therefore suitable for people with lactose intolerance.
In this research study, four methods of peanut milk preparation namely, by normal
soaking, soaking in 1% NaHCO3, roasting and pressure blanching. The proximate
analysis of peanut milk was carried out in the laboratory of College of Agricultural
Engineering, Bapatla. The proximate composition of peanut milk consists of
moisture content, protein content, carbohydrate content, fat content, ash content,
total solids and pH values. Quality of the milk prepared by these four different
methods was compared. The peanut milk was then converted into powder by spray
drying technology. Finally the nutritive value of peanut milk and powder were
compared. Based on the work done, the following conclusions were drawn.
1. The moisture content of peanut milk which was pressure blanching for 3
minutes recorded highest value (90.28% wb) whereas the peanut milk
prepared with 1% sodium bicarbonate recorded the lowest value (89.06%
wb). Peanut milk powder prepared in pressure blanching method for 2
minutes recorded the highest moisture content (6.53% wb) and peanut milk
powder prepared by blanching method for zero minutes recorded the lowest
moisture (4.51% wb).
2. The protein content of peanut milk which was pressure blanched for 2
minutes recorded highest value (3.74%) whereas the peanut milk prepared
through soaking in 1% sodium bicarbonate recorded the lowest value
(3.11%). Milk powder prepared by pressure blanching for zero minutes
recorded the highest protein (30.88%) and milk powder prepared by normal
soaking method recorded the lowest protein content (27.05%).
3. The carbohydrate content of peanut milk which was soaked in 1% sodium
bicarbonate recorded highest value (5.58%) whereas the peanut milk
prepared in roasting method recorded the lowest value (3.78%). The milk
Page 100
powder prepared in pressure blanching for zero minutes recorded the
highest value (19.72%) and milk powder prepared by in pressure blanching
for 2 minutes recorded the lowest value (14.61%).
4. The fat content of peanut milk which was prepared by roasting method
recorded highest value (3.53%) whereas the peanut milk prepared by
pressure blanching for 3 minutes recorded the lowest value (1.63%). Milk
powder prepared in roasting method recorded the highest value (48.35%)
and milk powder prepared by pressure blanching method for zero minutes
recorded the lowest value (40.89%).
5. The ash content of peanut milk prepared by soaking in 1% sodium
bicarbonate recorded highest value (0.26%) whereas the peanut milk
prepared pressure blanched for 3 minutes and 5 minutes recorded the
lowest value (0.15%). Milk powder prepared in normal soaking recorded
the highest ash content (2.86%) and milk powder prepared by pressure
blanched for 5 minutes recorded the lowest ash content (1.77%).
6. The crude fiber content of peanut milk powder which was prepared by
pressure blanching for 2 minutes recorded highest value (2.07%) whereas
the peanut milk powder normal soaking recorded the lowest value (1.11%).
7. The total solids of peanut milk which was soaked in 1% sodium
bicarbonate recorded highest value (11.00%) whereas the peanut milk
prepared pressure blanched for 3 minutes recorded the lowest value
(9.71%). Milk powder prepared in pressure blanching for 0 minutes
recorded the highest value (95.49%) and milk powder prepared by pressure
blanching for 2 minutes recorded the lowest value (93.57%).
8. The pH values of peanut milk was which was soaked in 1% sodium
bicarbonate recorded highest value (6.33) whereas the peanut milk prepared
by pressure blanching for 5 minutes recorded the lowest value (5.47). Milk
powder prepared by soaking in 1% sodium bicarbonate recorded the
highest value (6.33) and milk powder prepared by pressure blanching for 5
minutes recorded the lowest value (5.47).
9. It was observed that all the quality parameters of milk were less compared
to the raw peanuts.
Page 101
10. It was observed that the proteins, carbohydrates, fat and ash increased when
the milk was converted into powder by spray drying.
11. On comparison between peanut milk and peanut milk powder, it was
noticed that nutritionally peanut milk powder was good.
Page 102
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Appendix-A
Peanut milk
Composition
Traditional methods
Normal soaking Sodium
Bicarbonate Roasting
T1 T2 T3 T1 T2 T3 T1 T2 T3 Moisture Content (%)
89.05
89.45
89.10
88.90
88.95
89.15
89.30
89.05
89.45
Protein (%) 3.74 3.74 3.57 3.06 3.23 3.06 3.40 3.06 3.23 Carbohydrates (%) 4.78 4.56 4.78 5.76 5.67 5.31 3.41 4.31 3.63
Fat (%) 2.20 2.00 2.30 2.00 1.90 1.70 3.70 3.40 3.50
Ash(%) 0.23 0.25 0.25 0.28 0.25 0.27 0.19 0.18 0.19 Crude fiber (%) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Total Solids (%)
10.55
10.95
10.90
11.05
11.10
10.85
10.95
10.55
10.70
pH 6.16 6.13 6.14 6.33 6.35 6.33 6.05 6.08 6.06
Page 111
Appendix-B
Composition
Peanut milk
Pressure blanching
0 min 2 min 3 min 5 min
T1 T2 T3 T1 T2 T3 T1 T2 T3 T1 T2 T3 Moisture Content (%) 89.55 89.60 89.20 89.20 89.35 89.20 90.25 90.25 90.35 89.20 89.45 89.40
Protein (%) 3.40 3.74 3.40 3.74 3.91 3.57 3.23 3.23 3.57 3.23 3.06 3.91
Carbohydrates(%) 4.99 4.37 5.70 5.21 4.83 5.11 4.77 4.58 4.41 5.41 5.64 4.94
Fat (%) 1.90 2.10 1.50 1.70 1.70 1.90 1.60 1.80 1.50 2.00 1.70 1.60
Ash(%) 0.16 0.19 0.20 0.15 0.21 0.22 0.15 0.14 0.17 0.16 0.15 0.15
Crude fiber (%) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Total Solids (%) 10.45 10.40 10.80 10.80 10.65 10.80 9.75 9.75 9.65 10.80 10.55 10.60
pH 5.74 5.72 5.75 5.66 5.66 5.68 5.57 5.59 5.58 5.47 5.47 5.47
Page 112
Appendix-C
Peanut milk powder
Composition
Traditional methods
Normal soaking Sodium Bicarbonate Roasting
T1 T2 T3 T1 T2 T3 T1 T2 T3 Moisture Content (%) 4.56 5.24 4.72 4.96 5.72 5.21 5.26 5.29 5.73
Protein (%) 28.34 25.94 26.89 30.52 29.84 29.56 27.82 26.96 27.54
Carbohydrates(%) 18.07 17.78 18.83 17.49 20.18 18.70 14.25 16.34 15.17
Fat (%) 45.42 47.11 45.16 43.46 40.12 42.96 49.15 47.89 48.02
Ash(%) 2.56 2.95 3.09 2.34 2.96 2.05 1.96 2.05 2.34
Crude fiber (%) 1.05 0.98 1.31 1.23 1.18 1.52 1.10 1.47 1.20
Total Solids (%) 95.44 94.76 95.28 95.04 94.28 94.79 94.74 94.71 94.27
pH 6.16 6.13 6.14 6.33 6.35 6.33 6.08 6.05 6.06
Page 113
Appendix-D
Peanut milk powder
Composition
Pressure blanching
0 min 2 min 3 min 5 min
T1 T2 T3 T1 T2 T3 T1 T2 T3 T1 T2 T3 Moisture Content (%) 4.08 4.84 4.62 6.89 6.47 6.24 5.52 5.96 5.48 5.02 5.28 5.59
Protein (%) 30.52 31.20 30.92 28.20 28.59 27.97 29.24 27.54 27.98 28.90 28.12 29.09
Carbohydrates(%) 19.52 19.70 19.95 15.58 15.44 12.80 18.71 17.23 20.67 20.81 19.10 18.63
Fat (%) 41.98 40.92 39.78 45.40 46.91 48.52 43.25 45.94 42.89 42.54 44.04 42.98
Ash(%) 2.52 2.10 2.84 1.96 2.59 2.28 1.76 1.92 1.89 1.09 2.02 2.19
Crude fiber (%) 1.38 1.24 1.89 1.97 2.05 2.19 1.52 1.41 1.09 1.64 1.44 1.52
Total Solids (%) 95.92 95.16 95.38 93.41 93.53 93.76 94.48 94.04 94.52 94.98 94.72 94.41
pH 5.74 5.72 5.75 5.66 5.66 5.68 5.57 5.59 5.58 5.47 5.47 5.47
Page 114
VITA
Perugu Balachandra Yadav, was born on June 12th, 1993 at Bhumayapalli in
Andhra Pradesh state. He passed the intermediate examination with 91.00% from
Chaithanya Bharathi Arts & Science Junior College, Tirupathi. He joined College
of Agricultural Engneering, Madakasira, Ananthapuram, (A.P.) for B.Tech degree
in Agricultural Engineering, in 2010. After graduation with 80.01%, he joined the
Faculty of Agricultural Engineering, Indira Gandhi Krishi Vishwa Vidyalaya,
Raipur (C.G.) in the year 2014 for post graduation programme in the Department
of Agricultural Processing and Food Engineering.
Permanent Address:
Perugu Balachandra Yadav,
S/O Perugu Veeraiah,
Bhumayapalli (Village & Post),
Khajipet (Mandal),
Y.S.R. (District),
Andhra Pradesh.
PIN: 516203
Mobile: 9494986230
Email: [email protected]