Lipid Lagi

8/14/2019 Lipid Lagi

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LIPID Soluble in non-polar solvents and insoluble in polar solvents. Lipid is not polymers.

Lipids:

1. Fatty acids

2. Neutral fats and oils

3. Waxes4. Phospholipid

5. Sterols

6. Fat soluble vitamins


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Fatty Acids

O

R C OH

#1 Carbon Acid Group

O

R C OH

Non-polar End - Hydrophobic End(Fat-soluble tail)

Polar End - Hydrophilic End


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Saturated Fatty Acids

CH 3 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 C OH

O1245678 3

Octanoic Acid


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Unsaturated Fatty Acids

CH 3 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 C OHO1245678 3

CH 3 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 C OHO

1245678 3

3 - Octenoic Acid

3, 6 - Octadienoic Acid

Short hand: 8:1 ( 3)

8:2 ( 3,6)


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Cis 9 - Octadecenoic Acid (oleic)

Trans 9 - Octadecenoic Acid (elaidic acid)

O

CH 3(CH 2)7 C C (CH 2)7 C OH

HH

910

O

CH 3(CH 2)7 C C (CH 2)7 C OHH

H

Cis And Trans Fatty Acids


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Polyunsaturated Fatty Acids

Linoleic acid: Cis, cis, 9, 12 - Octadecadienoic acid

Linolenic acid: Cis, cis, cis 9, 12, 15 - Octadecatrienoic acid

Arachidonic acid: Cis, cis, cis, cis 5, 8, 11, 14 - Eicosatetraenoicacid

Linoleic Acid

Linolenic Acid

Arachidonic Acid


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Naturally-occurring fatty acids

R CH 2 CH CH CH 2 CH CH CH 2 C OH

O

7 6 5 4 3

1. Cis form

2. Not conjugated --- isolated double bond.

3. Even numbered fatty acids.


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CLASSIFICATION OF FATTY ACIDS PRESENTAS GLYCERIDES IN FOOD FATS

I. Saturated Fatty Acids

Butyric Butanoic CH3(CH2)2COOH butterfat

Caproic Hexanoic CH3(CH2)4COOH butterfat, coconutand palm nut oils

Caprylic Octanoic CH3(CH2)6COOH coconut and palmnut oils, butterfat

Capric Decanoic CH3(CH2)8COOH coconut and palmnut oils, butterfat

Lauric Dodecanoic CH3(CH2)10COOH coconut and palmnut oils, butterfatMyristic Tetradecanoic CH3(CH2)12COOH coconut and Palm nut oil, most

animal and plant fatsPalmitic Hexadecanoic CH3(CH2)14COOH practically all animal and

plant fatsStearic Octadecanoic CH3(CH2)16COOH animal fats and minor

component of plant fatsArachidic Eicosanoic CH3(CH2)18COOH peanut oil

CommonName

SystematicName

Formula Common source


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CommonName

SystematicName


II. Unsaturated Fatty Acids A. Monoethenoic Acids

Oleic Cis 9-octadecenoic C17H33COOH plant and animal fats

Elaidic Trans 9-Octadecenoic C17H33COOH animal fats

B. Diethenoic Acids

Linoleic 9,12-Octadecadienoic C17H31COOH peanut, linseed, andcottonseed oils

C. Triethenoid Acids Linolenic 9,12,15-Octadecatrienoic C17H29COOH linseed and other seed

oilsEleostearic 9,11,13-Octadecatrienoic C17H29COOH peanut seed fats

D. Tetraethenoid Acids

Moroctic 4,8,12,15-Octadecatetraenoic

C17H27COOH fish oils

Arachidonic 5,8,11,14- C19H31COOH traces in animal fats


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Common and Systematic Names of Fatty AcidsCommon and Systematic Names of Fatty Acids

CommonName

SystematicName


A. Monoethenoic Acids

Oleic Cis 9-octadecenoic C17H33COOH plant and animal fats

Elaidic Trans 9-Octadecenoic C17H33COOH animal fats

B. Diethenoic AcidsLinoleic 9,12-Octadecadienoic C17H31COOH peanut, linseed, and

cottonseed oils C. Triethenoid Acids Linolenic 9,12,15-Octadecatrienoic C17H29COOH linseed and other seed

oilsEleostearic 9,11,13-Octadecatrienoic C17H29COOH peanut seed fats

D. Tetraethenoid Acids

Moroctic 4,8,12,15-Octadecatetraenoic

C17H27COOH fish oils

Arachidonic 5,8,11,14-Eicosatetraenoic

C19H31COOH traces in animal fats


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C4 - 8 -

C6 - 4 970C8 16 75

C10 31 6

C12 44 0.55

C14 54 0.18

C16 63 0.08

Fatty Acids M.P.(0C) mg/100 ml Soluble in H2O

C18 70 0.04

CHARACTERISTICS OF FATTY ACIDS


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Effects of Double Bonds on the Melting Points

16:0 6016:1 118:0 6318:1 16

18:2 -518:3 -1120:0 75

F. A. M. P. (0C)

20:4 -50

M.P.

# Double bonds


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FAT AND OILS

Mostly Triglycerides:

O

H2C OH

HC OH

H2C OH

HO C R

HO C R

HO C R

O

O

O

H2C O C R O

OH2C O C R

HC O C R + + 3 H 2O

Glycerol 3 Fatty Acids


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GLYCERIDES

Monoglyceride ( - monostearin) Diglyceride ( , ' - distearin)

H2C OH

HC OH

H2C O

O

C (CH 2)16 CH 3

H2C O

HC OH

H2C OO

C (CH 2)16 CH 3

C (CH 2)16 CH 3

O

Triglyceride ( - palmityl distearin)

H2C O

HC O

H2C O

O

C (CH 2)16 CH 3

C (CH 2)16 CH 3

O

O

C (CH 2)14 CH 3

( C18 )

(C16 )

(C18 )


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- oleodipalmitin

1 - oleodipalmitin

Oleic

PalmiticPalmitic

OPP

- Linoleyldiolein

1 - Linoleyldiolein

Oleic

Linoleic

Oleic LOO


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FATS AND OILS ARE PRIMARILY TRIGLYCERIDES (97-99%)

Vegetable oil - world supply - 68%

Cocoa butter - solid fat

Oil seeds - liquid oil

Animal fat - 28% (from Hogs and Cattle)

Marine oil - 4%

Whale oil

cod liver oil


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Fatty Acids (%) of Fats and Oils

4 36 38 2 6

10 3 612 3 4414 10 18 116 26 11 4 12

16:1 7 118:0 15 6 3 218:1 29 7 18 2418:2 2 2 53 54

Fatty Acids Butter Coconut Cottonseed Soybean

18:3 2 8


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MELTING POINTS OF TRIGLYCERIDES

C6 -15

C12 15

C14 33

C16 45

C18 55C18:1 (cis) -32

Triglyceride Melting Point (C)

C18:1 (trans) 15


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WAXES Fatty acids + Long chain alcohol

Important in fruits:

3. Natural protective layer in fruits, vegetables, etc.

4. Added in some cases for appearance and protection.

Beeswax (myricyl palmitate), Spermaceti (cetyl palmitate)

O

C30 H61 O C C 15 H31

OC16 H33 O C C 15 H31


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PHOSPHOLIPID

Lecithin (phosphatidyl choline)

O

O

H2C O C R O

R C O CH

H2C O P O CH 2 CH 2 N+

CH 3CH 3

CH 3

O_

Phosphatidic Acid Choline


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STEROLS

Male & female sex hormones

Bile acids

Vitamin D

Adrenal corticosteroids

Cholesterol

HO

H 3 C

H 3 C

H 3 C CH 3

CH 3

123 4 5

6 789

1011

1213

14 15

1617

18

21 22

19

20


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FAT SOLUBLE VITAMINS

Vitamin A:

CH2 OHCH3 CH3

CH3

CH 3H3C

12

34

5

67

89


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Vitamin D2:

Vitamin E:

HO

CH 2

HH

H 3 C

H 3 C CH 3

CH 3

CH 3

OR

1

R 2

HO

R 3

CH 3(CH 2CH 2CH 2CH 2)2CH 2CH 2CH 2CH(CH 3)2

CH 3


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ANALYTICAL METHODS TO MEASURE THECONSTANTS OF FATS AND OILS

1. Acid Value

2. Saponification Value3. Iodine Value

4. Gas Chromatographic Analysis for Fatty Acids

5. Liquid Chromatography

6. Cholesterol Determination


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1. Acid Value

Number of mgs of KOH required to neutralize the FreeFatty Acids in 1 g of fat.

AV =ml of KOH x N x 56Weight of Sample

= mg of KO


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2. Saponification Value

Saponification - hydrolysis of ester under alkalinecondition.

O

C R

O

O

C R

C R O

H2C O

HC O

H2C O

KOH

H

H

H

H2C O

HC O

H2C O

R C OK + 3 + 3


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Saponification # --mgs of KOH required to saponify 1 g of fat.

1. 5 g in 250 ml Erlenmeyer.

2. 50 ml KOH in Erlenmeyer.

3. Boil for saponification.4. Titrate with HCl using phenolphthalein.

6. Conduct blank determination.

B - ml of HCl required by Blank.

S - ml of HCl required by Sample.

SP# =56.1(B -S) x N of HCl

Gram of Sample

2. Saponification Value Determination


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Iodine Value = (ml of Na 2S2O3 volume for blank - ml of Na 2S2O3 volume for sample) N of Na 2S2O3 0.127g/meq 100

Weight of Sample (g)

CH CH CH CHCl I

ICl

Iodine chloride

+

ICl KI KCl

I 2

I 2

Na 2 S 2 O 3 Na 2 S 4 O 6 NaI

+

+ 2 2+

+Excess unreacted ICl

Iodine Value Determination


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Iodine Numbers of Triglycerides

Palmitoleic Acid 1 95

Oleic Acid 1 86

Linoleic Acid 2 173

Linolenic Acid 3 261

Fatty Acids # of Double-bonds Iodine #

Arachidonic Acid 4 320


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Compositions (%) of Fatty Acids of Fats

1 5 5 20 40 30

2 20 35 40 5

3 10 50 40

4 20 40 40

5 10 20 20 10 20 20

Fat C4 C6 C10 C16 C18 C18:1 C18:2 C18:3 C20:4

6 100


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4. GC Analysis for Fatty Acids

1. Extract fat.

2. Saponify (hydrolysis under basic condition).

3. Prepare methyl ester (CH3ONa).

4. Chromatography methyl ester.

5. Determine peak areas of fatty acids.

Fatty acids are identified by retention time.

6. Compare with response curve of standard.


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Fatty Acids Methyl Esters:

14

18:1

18:2 2018:3

22

21:1 2416 18

Time

Response

GC condition: 10% DEGS Column (from supelco)

Column temperature 200C.


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5. TRIGLYCERIDE ANALYSIS BY LIQUIDCHROMATOGRAPHY

Soybean Oil

Solvent CH 3CN/HF

Column 84346 (Waters Associates)

RESPONSE

RETENTION TIME


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Oleate-containing triglycerides in olive oil

OL2 54:5 44

O2L 54:4 46

OPL 52:3 46

O3 54:3 48

OSL 54:3 48

O2P 52:2 48

O2S 54:2 50

OPS 52:1 50

Fatty AcidComposition

Total Acyl Carbons:Unsaturation

Equivalent Carbon Number

OS2 54:1 52


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6. CHOLESTEROL DETERMINATION

Enzymatic Determination: Cholesterol Oxidase

HO OH2O2

Cholesterol Oxidase

etc. +

H2O2

CH3O OCH3

H2 N NH2 HN NH

OCH3CH3O

H2OPeroxidas e+ +

0-Dianisidine Oxidized 0-Dianisidine

(Colorless) (Brown color)At 440 nm


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Spectromertic Absorption Standard Curve of CholesterolSpectromertic Absorption Standard Curve of Cholesterol

Cholesterol by GLC

1. Prepare cholesterol butyrate.

2. Analyze by GLC.

time in GC - 15 min.sensitivity - 10 -7 g.

g/ml Cholesterol

Absorptionat 440 nm


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1. Gravimetric Method

(1) Wet Extraction - Roese Gottlieb & Mojonnier.

For Milk:

1) 10 g milk + 1.25 ml NH4OH mix. solubilizes protein and neutralizes.

2) + 10 ml EtOH - shake. Begins extraction, prevents

gelation of proteins.3) + 25 ml Et2O - shake and mix.

4) + 25 ml petroleum ether, mix and shake.


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(2) Dry Extraction - Soxhlet Method .

Sample in thimble is continuously extracted with ether

using Soxhlet condenser. After extraction, directmeasurement of fat

- evaporate ether and weigh the flask.

Indirect measurement - dry thimble and weigh thimble andsample.


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Soxhlet Method .


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2. Volumetric Method (Babcock, Gerber Methods)

Theory:

2. Treat sample with H2SO4 or detergent.

3. Centrifuge to separate fat layer.

4. Measure the fat content using specially calibrated bottles.

Methods:

1. Known weight sample.2. H2SO4 - digest protein, liquefy fat.

3. Add H2O so that fat will be in graduated part of bottle.

4. centrifuge to separate fat from other materials completely.


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REACTIONS OF FATS

Hydrolytic Rancidity:

1. Triglyceride -> Fatty acidsSpecially C4 butyric acid (or other short chain fattyacids) are the real problem.

2. By lipase.


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P F i f Li l i A id


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Pentane Formation from Linolenic Acid

+

+

_

.+

.-

+

CH 3 (CH 2)3 CH 2 CH CH CH CH CH CH 2 COOH

CH 3 (CH 2)3 CH 2 CH CH CH 2 CH CH CH 2 COOH

.

H

.


O

O

H

O

O



O

Initiation (metal)

Propagation

Propagation.

O2

H

OH.HydroperoxideDecomposition

CH 3 (CH 2)3 CH 2 H C CH CH CH CH CH 2 COOH

CH 3 (CH 2)3 CH 3

O.

H.Termination

Pentane

14 13 12 11 10 9

12 11 10 9

12 11 10 9

12 11 10 9

12 11 10 9

12 11 10 9

n

n

n

- n

n

n


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ANALYSIS OF FLAVOR QUALITY & STABILITY OF OIL

1. Peroxide Value

KI CH 3 C OH HI CH 3 C OK

O O

ROOH HI I 2 H 2 O ROH

I 2 Na 2 S 2 O 3 NaI Na2 S 4 O 6

A.

B.

C.

+

+

+

+

+

+

+

2

2

2

Peroxide Value = ml of Na2S2O3 N 1000

(milliequivalent peroxide/kg of sample) Grams of Oil


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3. TBA Test.

To determine the rancidity degree of meat or fish product.

N

N

HS

OH

OH

C CH 2 C

O

H

O

H

OH

OH

HS

N

N

OH

SH

N

N

CH CH CH

HO

H 2O

Colored Pigment

+

+ 2

Lipid Lagi

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