TEKNOLOGI PENGOLAHAN DAN PENGAWETAN PANGAN (TPG 630) Dr. Ir. Sugiyono, M.AppSc. Departemen Ilmu dan Teknologi Pangan Fateta IPB Kampus IPB Darmaga PO Box.

TEKNOLOGI PENGOLAHANTEKNOLOGI PENGOLAHAN DAN DAN PENGAWETAN PENGAWETAN PANGAN (TPG 63PANGAN (TPG 6300))

Dr. Ir. Sugiyono, M.AppSc.Dr. Ir. Sugiyono, M.AppSc.Departemen Ilmu dan Teknologi Pangan Departemen Ilmu dan Teknologi Pangan

Fateta IPBFateta IPB

Kampus IPB Darmaga PO Box 220 Bogor Kampus IPB Darmaga PO Box 220 Bogor 1600216002

Telp/Fax. 0251-626725Telp/Fax. 0251-626725

Email : [email protected] : [email protected]

StarchStarch

Complex carbohydrate made up of two Complex carbohydrate made up of two componentscomponents

Components:Components:– AmyloseAmylose– AmylopectinAmylopectin

Properties depend on amounts of the Properties depend on amounts of the componentscomponents

SourcesSources

Roots/TubersRoots/Tubers– PotatoPotato– ArrowrootArrowroot– CassavaCassava– Sweet potatoSweet potato

CerealCereal– CornCorn– Waxy cornWaxy corn– WheatWheat– RiceRice– Waxy riceWaxy rice

Starch vs FlourStarch vs Flour

Starch is obtained from extraction with Starch is obtained from extraction with water, e.g. tapioca, corn starch, etc.water, e.g. tapioca, corn starch, etc.

Flour is produced by milling process, e.g.Flour is produced by milling process, e.g.

wheat flour, rice flour, etc.wheat flour, rice flour, etc.

AmyloseAmylose

Linear component Linear component of starchof starch

Contains 1,4-Contains 1,4-alpha-glucosidic alpha-glucosidic bondsbonds

Molecular weight: Molecular weight: less than 0.5 less than 0.5 millionmillion

Can form coils Can form coils which will trap which will trap iodine and turn iodine and turn blueblue

AmylopectinAmylopectin

Branched Branched component of starchcomponent of starch

Contains 1,4-alpha-Contains 1,4-alpha-glucosidic as well as glucosidic as well as 1,6-alpha-glucosidic 1,6-alpha-glucosidic bondsbonds

Molecular weight: Molecular weight: 50-500 million50-500 million

Limited coiling Limited coiling causes purplish-red causes purplish-red color when iodine color when iodine addedadded

Amylose vs. AmylopectinAmylose vs. Amylopectin

Starches usually contain more amylopectin Starches usually contain more amylopectin than amylosethan amylose

Generally roots/tubers contain more Generally roots/tubers contain more amylopectin than cerealsamylopectin than cereals

Roots/Roots/ttubers: 80% amylopectinubers: 80% amylopectin Cereals: 75% amylopectinCereals: 75% amylopectin Waxy corn and rice contain virtually all Waxy corn and rice contain virtually all

amylopectinamylopectin

Starch CompositionStarch Composition

Starch % amylose % amylopectin Tapioca 17% 83% Potato ~20% ~80% Wheat 25-26% ~75% Corn 24-28% ~75 Waxy corn ~0% ~100% Hi amylose Rice

~ 75% 22%

~ 25% 78%

Starch GranuleStarch Granule

Made in the cytoplasm of plant cellsMade in the cytoplasm of plant cells Amylopectin forms in concentric circles with Amylopectin forms in concentric circles with

amylose dispersed in betweenamylose dispersed in between Held together by hydrogen bondsHeld together by hydrogen bonds The granule swells when heated in waterThe granule swells when heated in water

Starch GranuleStarch Granule

FunctionsFunctions

GelatinizationGelatinization– Structure in baked productsStructure in baked products– Thickener in sauces, soups, and dressingsThickener in sauces, soups, and dressings

DextrinizationDextrinization GelationGelation

– Pie fillingPie filling

GelatinizationGelatinization

When starch is heated in waterWhen starch is heated in water Hydrogen bonds break, allowing water to enter the Hydrogen bonds break, allowing water to enter the

granule and the granule swellsgranule and the granule swells Amylose migrates out of the granuleAmylose migrates out of the granule H-bonding between water and amylopectin H-bonding between water and amylopectin

increasesincreases Reduced free water changes the viscosity of the Reduced free water changes the viscosity of the

starch mixture, thickening itstarch mixture, thickening it

Gelatinization and TemperatureGelatinization and Temperature

Gradually thicken with temperatureGradually thicken with temperature Can be heated to 100Can be heated to 100ooC without much C without much

granule rupturegranule rupture If held at 95If held at 95ooC will implode and lose C will implode and lose

viscosityviscosity

Gelatinization and Type of StarchGelatinization and Type of Starch

Best thickening Best thickening ability: potato starchability: potato starch

Worst thickening Worst thickening ability: wheat starchability: wheat starch

More More amylopectin=more amylopectin=more translucent=more translucent=more stringystringy

Viscosity and Type of StarchViscosity and Type of Starch

Gelatinization and SugarGelatinization and Sugar

Used together in pie fillings and puddingsUsed together in pie fillings and puddings Sugar competes with the starch for water so less Sugar competes with the starch for water so less

water available for gelatinizationwater available for gelatinization Delays gelatinization and decreases viscosityDelays gelatinization and decreases viscosity Increases gelatinization temperatureIncreases gelatinization temperature The more sugar added, the longer the delayThe more sugar added, the longer the delay Disaccharides have a stronger effect than Disaccharides have a stronger effect than

monosaccharidesmonosaccharides

Gelatinization and AcidGelatinization and Acid

Used together in fruit pie fillings, specifically Used together in fruit pie fillings, specifically lemon fillingslemon fillings

Acid breaks down starch molecules so the Acid breaks down starch molecules so the paste is thinnerpaste is thinner

Decreases viscosityDecreases viscosity Acid effect can be minimized by adding after Acid effect can be minimized by adding after

gelatinization or heating rapidlygelatinization or heating rapidly

GelationGelation

As a starch paste cools, a gel is formedAs a starch paste cools, a gel is formed Free amylose molecules lose energy as the Free amylose molecules lose energy as the

temperature decreases and form hydrogen temperature decreases and form hydrogen bondsbonds

The bonds create a network that holds the The bonds create a network that holds the swelled granules in placeswelled granules in place

Gelation and Starch SourceGelation and Starch Source

The more amylopectin (less amylose), the The more amylopectin (less amylose), the softer the gelsofter the gel

Potato starch=high amylopectin=good Potato starch=high amylopectin=good thickening agent=soft gelthickening agent=soft gel

Corn starch=less amylopectin=less effective Corn starch=less amylopectin=less effective thickening agent=strong gelthickening agent=strong gel

Gelation and Other EffectsGelation and Other Effects

HeatingHeating– Moderate temperature and rate of heatingModerate temperature and rate of heating– Enough amylose needs to be released from the granule Enough amylose needs to be released from the granule

without the granule burstingwithout the granule bursting

AgitationAgitation– Agitation during cooling disrupts amylose networkAgitation during cooling disrupts amylose network– Should mix flavorings immediately after removing from Should mix flavorings immediately after removing from

heatheat

Gelation and Other EffectsGelation and Other Effects

SugarSugar– Decreases gelatinization and amylose releaseDecreases gelatinization and amylose release– Softer gelSofter gel

AcidAcid– Decreases gelatinization by hydrolysis of Decreases gelatinization by hydrolysis of

granulesgranules– Softer gelSofter gel

Aging GelsAging Gels

SyneresisSyneresis– Loss of water from a gelLoss of water from a gel– Amylose molecules pull together, squeezing water outAmylose molecules pull together, squeezing water out

RetrogradationRetrogradation– Realignment of amylose moleculesRealignment of amylose molecules– Hydrogen bonds break and reform into more orderly Hydrogen bonds break and reform into more orderly

crystalscrystals– Can by reversed by gently heatingCan by reversed by gently heating– Examples: refrigerated pudding, stale breadExamples: refrigerated pudding, stale bread

DextrinizationDextrinization

When starch is heated without waterWhen starch is heated without water A higher temperature is reached than with A higher temperature is reached than with

waterwater Bonds break throughout the starch forming Bonds break throughout the starch forming

dextrinsdextrins

Genetically-modified StarchesGenetically-modified Starches

Waxy starchWaxy starch– High in amylopectinHigh in amylopectin– Used in fruit pies because thickens well, but does not Used in fruit pies because thickens well, but does not

gel wellgel well– Have good freeze-thaw stabilityHave good freeze-thaw stability

High amylose starchHigh amylose starch– Amylose creates strong bonds to form strong gelsAmylose creates strong bonds to form strong gels– Used in edible films to coat foodUsed in edible films to coat food

SStarchtarch Characterization Characterization

Line spread test:Line spread test:– Measures thickening powerMeasures thickening power– Poor heated starch into cylinder, lift cylinder and Poor heated starch into cylinder, lift cylinder and

measure spread after specified time using measure spread after specified time using concentric circlesconcentric circles

Universal Texture Analyzer:Universal Texture Analyzer:– Measures gel strengthMeasures gel strength

Percent sag:Percent sag:– Measures gel strengthMeasures gel strength– Measure molded gel height and compare to Measure molded gel height and compare to

unmolded gel heightunmolded gel height– Stronger gel=small % sag, weaker gel=large % Stronger gel=small % sag, weaker gel=large %

sagsag

Modified StarchesModified Starches

Physically or chemically modifying native starchesPhysically or chemically modifying native starches Are used for specific applications in the food Are used for specific applications in the food

industry, Why?industry, Why? Native starches have undesirable qualities:Native starches have undesirable qualities:

– Poor processing tolerance to heat, shear and acidPoor processing tolerance to heat, shear and acid– Poor texturesPoor textures– Do not store, hold, and freeze/thaw wellDo not store, hold, and freeze/thaw well

Starch Modification Starch Modification 1.1. Acid hydrolysisAcid hydrolysis2.2. Cross linkingCross linking3.3. OxidationOxidation4.4. SubstitutionSubstitution5.5. Pre-gelatinizationPre-gelatinization6.6. Hydrothermal treatmentHydrothermal treatment

- - meningkatkan kejernihan gel / pastameningkatkan kejernihan gel / pasta- - dpt dilakukan dg cara kering atau dpt dilakukan dg cara kering atau basahbasah- - asam :asam :

--

Acid hydrolysis (Acid Thinning) or Acid hydrolysis (Acid Thinning) or Thin-Boiling StarcheThin-Boiling Starchess

Process : dry or wet usingProcess : dry or wet using

HCl, HHCl, H22SOSO44

Use:Use:– Pass freely through pipesPass freely through pipes

Acid-hydrolyzed starchAcid-hydrolyzed starch– Hydrolyzes 1,6-alpha-glucosidic bondsHydrolyzes 1,6-alpha-glucosidic bonds– Amylopectin in smaller piecesAmylopectin in smaller pieces– Decreases thickening power, but makes a strong gel Decreases thickening power, but makes a strong gel

because hydrogen bonds form more readilybecause hydrogen bonds form more readily– Increases clarity of gelIncreases clarity of gel– Used in candy productsUsed in candy products

CCross linkingross linking

-- cross links between hydroxyl ends of cross links between hydroxyl ends of two starch molecules in a starch granuletwo starch molecules in a starch granule- - use use acetic anhydride, succinic acetic anhydride, succinic anhydride, or ethylene oxideanhydride, or ethylene oxide, phosphorus , phosphorus chloridechloride, , sodium trimetasodium trimetaphosphatephosphate, , epiepichchlorohlorohyydrin, drin, etc,etc,-- Wet and alkali conditionsWet and alkali conditions- - pH, temperature, and process duration pH, temperature, and process duration affect cross linking processaffect cross linking process

Cross-linked StarchCross-linked Starch

Use:Use:– Increases storage time because of reduced Increases storage time because of reduced

retrogradationretrogradation– More stable at high temperature, with agitation, and with More stable at high temperature, with agitation, and with

acid additionacid addition– Salad dressings, baby foods, pie fillingsSalad dressings, baby foods, pie fillings

Cross-linked starch moleculesCross-linked starch molecules– Alter hydroxyl ends under alkaline conditions by acetic Alter hydroxyl ends under alkaline conditions by acetic

anhydride, succinic anhydride, or ethylene oxideanhydride, succinic anhydride, or ethylene oxide

-- ExampleExample : :

2 StOH + Na2 StOH + Na33PP33OO9 9

StO-P-OSt + NaStO-P-OSt + Na22HH22PP22OO77

Catalist Catalist : NaOH, Na: NaOH, Na22COCO3, 3, Ca(OH)Ca(OH)22

Catalist

O

ONa

Cross linked StarchesCross linked Starches Vary in degree of cross linkingVary in degree of cross linking May be double modified – substituted starchesMay be double modified – substituted starches Reduce elasticity found in native starchesReduce elasticity found in native starches More tolerant to high shear in processingMore tolerant to high shear in processing Less effected by acid, sugarLess effected by acid, sugar More resistant to heatMore resistant to heat Not easily swellNot easily swell High viscosityHigh viscosity

Cross Linked StarchCross Linked Starch

Degree of cross linking Application

Lightly cross linked Neutral and slightly acidic foods

Medium cross linked High acid foods;delay gelation for some canned foods; foods stored at low temperature;

Highly cross linked High shear, high temperature

Viscosity and Cross-linked Viscosity and Cross-linked StarchesStarches

OOxidationxidation (Bleaching) (Bleaching)

- - Uses Uses h hyydrogen perodrogen peroxidexide, , perasetperasetic ic acidacid, ammonium persul, ammonium persulphatephate, sodium , sodium hhyypopochloritechlorite

- - Wet conditionsWet conditions - Pigment and hydroxyl oxidation- Pigment and hydroxyl oxidation- More whitenessMore whiteness- Not easily retrogradeNot easily retrograde- Softer gelSofter gel

Pre-gelatinized StarchesPre-gelatinized Starches

Use:Use:– Instant puddingInstant pudding

Dehydrated gelatinized starchDehydrated gelatinized starch– Heated so granule swells and then dehydratedHeated so granule swells and then dehydrated– Swells when water added, no heat necessarySwells when water added, no heat necessary– Decreases preparation timeDecreases preparation time– Physical changePhysical change

Substitution Substitution

-- changes hydroxyl groups with other changes hydroxyl groups with other functional groupsfunctional groups

Example Example : : hhydroxypropylatin usingydroxypropylatin using

proppropyylenlenee o oxidexide

St - OH + CHSt - OH + CH2 2 – CH – CH– CH – CH33

St – OCHSt – OCH22

OH-

O

CH – CH3

OH

SubstitutedSubstituted Starches Starches

Starch estersStarch esters– Acetate StarchAcetate Starch– Starch phosphateStarch phosphate– SuccinylatedSuccinylated

Starch ethersStarch ethers– carboxy methyl starchcarboxy methyl starch– hydroxyl propyl starchhydroxyl propyl starch

Substituted StarchesSubstituted Starches

Made from starch in granule formMade from starch in granule form Low level subsitution interupts linearity and –Low level subsitution interupts linearity and –

– retards retrogradation, retards retrogradation, – increase water binding capacity, increase water binding capacity, – lowers gelation temperature, lowers gelation temperature, – introduction of hydrophobic groups impart introduction of hydrophobic groups impart

emulsification propertiesemulsification properties– Alters clarityAlters clarity

Acetate starchAcetate starch

Class: Substituted starchClass: Substituted starch Acetylated starch.Acetylated starch. Granular starch ester with Granular starch ester with

a CHa CH33CO-group introduced CO-group introduced Improves paste stability and clarity.Improves paste stability and clarity. The acetate groups act as pegs on the The acetate groups act as pegs on the

amylopectin chains to reduce or prevent amylopectin chains to reduce or prevent retrogradation. Acetate starches are used in retrogradation. Acetate starches are used in chilled or frozen preparations such as chilled or frozen preparations such as icecream cheesecakes etc.icecream cheesecakes etc.

The level of acetelation can be altered to The level of acetelation can be altered to tailor the properties.tailor the properties.

Phosphate starchPhosphate starch

There are two classes of phosphate starches.There are two classes of phosphate starches.   Substituted starch phosphate estersSubstituted starch phosphate esters. eg. . eg.

monostarch phosphate. monostarch phosphate. – Similar in function to starch acetate. The Similar in function to starch acetate. The

phosphates act as pegs to prevent retrogradation.phosphates act as pegs to prevent retrogradation.–   Improves paste stability and clarityImproves paste stability and clarity

Crosslinked starch esters. Crosslinks starch Crosslinked starch esters. Crosslinks starch chains to stabilize viscosity and reduce shear chains to stabilize viscosity and reduce shear thinning.thinning.

Succinylated starchSuccinylated starch

This is a substituted starch esterThis is a substituted starch ester   Retards retrogradationRetards retrogradation Increases hydrophobicity and can assist in Increases hydrophobicity and can assist in

emulsificationemulsification

Substituted starch etherSubstituted starch ether

General term for three classes of starch General term for three classes of starch ether substitution are:ether substitution are:– Anionic (Carboxy methyl starches),Anionic (Carboxy methyl starches),– cationic (Quaternery ammonium) and cationic (Quaternery ammonium) and – Non-Ionic (Hydroxy alkyl starches).Non-Ionic (Hydroxy alkyl starches).

Substituted starch ether (cont)Substituted starch ether (cont)

Substituted starch ethers Substituted starch ethers have improved have improved clarity, better resistance to retrogradaion and clarity, better resistance to retrogradaion and improved viscosityimproved viscosity

The substituted starch ethers (carboxy methyl The substituted starch ethers (carboxy methyl starch and hydroxyl propyl starch) are generally starch and hydroxyl propyl starch) are generally preferred as they offer improved functionality preferred as they offer improved functionality compared with the substituted starch esters compared with the substituted starch esters (starch acetate and monostarch phosphates). (starch acetate and monostarch phosphates). Crosslinked hydroxyl-propyl starches are Crosslinked hydroxyl-propyl starches are among the most functional of the food grade among the most functional of the food grade modified starches.modified starches.

Hydroxypropyl starchHydroxypropyl starch..

The hydroxyl-propyl groups act as pegs to The hydroxyl-propyl groups act as pegs to prevent retrogradation. prevent retrogradation.

Similar to the starch acetates above but the Similar to the starch acetates above but the substituted group is larger,substituted group is larger,

Substituted or Cross Linked?Substituted or Cross Linked?

Crosslinking protects against high shear, acid Crosslinking protects against high shear, acid processing and prolonged heating. It depends on processing and prolonged heating. It depends on the food or other use, processing conditions and the food or other use, processing conditions and the cost of the modified starch.the cost of the modified starch.

Most modified starches are BOTH crosslinked and Most modified starches are BOTH crosslinked and substituted, It is the level of each of these substituted, It is the level of each of these processes that is used to adjust functionality. The processes that is used to adjust functionality. The levels of both crosslinking and substitution are levels of both crosslinking and substitution are adjusted depending on end use.adjusted depending on end use.

Hydrothermal Treatment :Hydrothermal Treatment :

-A-Annealingnnealing : dilakukan dengan mengkondisikan : dilakukan dengan mengkondisikan pati pada kadar air tinggi kemudian dipanaskan pati pada kadar air tinggi kemudian dipanaskan pada suhu di bawah titik gelatinisasi pada suhu di bawah titik gelatinisasi

- H- Heat moisture treatmenteat moisture treatment (HMT) : (HMT) : dilakukan dilakukan dengan cara memanaskan pati di atas titik dengan cara memanaskan pati di atas titik gelatinisasinya pada kadar air yang terbatas gelatinisasinya pada kadar air yang terbatas (kurang dari 35%).(kurang dari 35%).

Resistant StarchResistant Starch

Small intestine is unable to digest, limited digestion Small intestine is unable to digest, limited digestion in large intestinein large intestine

ClassificationsClassifications– RS1: trapped in cells (seeds/legumes)RS1: trapped in cells (seeds/legumes)– RS2: native starch (raw potatoes, bananas, waxy maize)RS2: native starch (raw potatoes, bananas, waxy maize)– RS3: crystalline, non-granular starch (cooked potatoes)RS3: crystalline, non-granular starch (cooked potatoes)– RS4: chemically modifiedRS4: chemically modified

Can contribute fiber to food without the fat that bran Can contribute fiber to food without the fat that bran hashas

Takes up less water than other fiber, making dough Takes up less water than other fiber, making dough less stickyless sticky

Smooth even textureSmooth even texture Less than 3 cal/gLess than 3 cal/g

GluGluccososee / Fru / Frucctostose Syrup from Starchese Syrup from Starches

- - hhydrolysis using acid, acidydrolysis using acid, acid – enz – enzyymmee, , oror

enzenzyymmee –enz –enzyymmee

StarchStarch

Glucose syrupGlucose syrup

FFrurucctostose syrupe syrup

-, -amylase, glucoamylase

Glucose isomerase

Glucose Glucose Production ProcessProduction Process

EmulsionCornstarchConvert

GlucoamylaseAdd in

Clean and Dry

Filter

Discolor

Ion exchange

Inspissation

Crystallization and separation

Glucose

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