STARCH MODIFICATIONS

Question 1

PHYSICAL MODIFICATION

Answer 1

PRE-GELATINIZED STARCH

Question 2

PRE-GELATINIZED STARCH

Answer 2

Starch is pre-cooked or ‘instantized’ by simultaneously cooking
and drying

Question 3

Pre-gelatinization involves

Answer 3

heating starch in the presence of water
to swell the granules, followed by drying the swollen starch.

Question 4

Disadvantages: of pre gelatinized starch

Answer 4

• Difficult to disperse
• Can form lumps
• Coarse texture

Question 5

The pregelatinized starch can be rehydrated easily in cold water

Answer 5

, forming a
gel or paste without the need for further cooking

Question 6

Instant solubility of pre gelatinzed starch is due to the disruption

Answer 6

of the granular structure during
the gelatinization process.

Question 7

Pregelatinization of Starch in a Waternonsolvent Solution

Answer 7

Starch is suspended in a solution that consists of water and a nonsolvent. The nonsolvent can be an organic solvent such as ethanol, acetone, polyols e

Question 8

Final Product: The dried starch is obtained as a powder.
This starch can be easily rehydrated i

Answer 8

in cold water,
forming a paste without the need for further heatin

Question 9

Starch Granule Disruption by mechanical Force

Answer 9

Involves mechanical, physical, or
enzymatic processes that break down larger granules into smaller particles.

Question 10

Mechanical methods of starcg granule disruption

Answer 10

Milling,
High pressure homogenization

Question 11

physical methods of starcg granule disruption

Answer 11

Ultrasonication, Spray drying

Question 12

combination methods of starcg granule disruption

Answer 12

High shear mixing
and enzyme treatment

Question 13

disrupted granules Applications

Answer 13

Improved Texture in Low-Fat Foods, Enhanced Stability in Emulsions, Quick Hydration and Thickening

Question 14

Smaller starch granules can mimic the
mouthfeel of fats

Answer 14

Suitable as fat replacers in dairy
products, dressings, and baked goods

Question 15

The fine size and increased surface area
of smaller granules improve

Answer 15

their ability
to stabilize emulsion

Question 16

Hydrate more rapidly and uniformly

Answer 16

Ideal for instant food products such as
soups, sauces, and desserts.

Question 17

HYDROTHERMAL TREATMENT. Annealing

Answer 17

Annealing involves treating starch granules
in excess water (above 40% moisture) at
temperatures below their gelatinization
point for an extended period.

Question 18

Annealing

Answer 18

reorganizes the crystalline
structure, enhancing the granules’ thermal
stability and improving their functional
properties.

Question 19

Heat-Moisture Treatment (HMT)

Answer 19

T involves treating starch with limited
water content (10-30% moisture) at higher
temperatures (usually above the
gelatinization temperature) for a specific
time.

Question 20

hmt

Answer 20

increases the starch’s
resistance to enzymatic hydrolysis and alters
its gelatinization and pasting properties

Question 21

CHEMICAL MODIFICATION-LOW VISCOSITY STARCH

Answer 21

Starch subjected to a treatment, which resulted in rupture of some of the glycosidic bonds in the starch molecules – cause viscosity to decrease

Question 22

ADVANTAGES LOW VISCOSITY STARC

Answer 22

• Can be cooked in water at higher concentration (10-65% wt) Than native starches (10%)
• Needed in application where a high solid starch paste with pumpable and workable viscosity is required

Question 23

ACID MODIFIED STARCHES

Answer 23

treated with a dilute acid (typically hydrochloric acid or sulfuric acid) under controlled conditions to partially hydrolyze the starch molecules.

Question 24

Mechanism OF ACID MODIFIED STARCH

Answer 24

Causes partial hydrolysis of the glycosidic bonds in the starch molecules, breaking down the long chains of amylose and amylopectin into shorter fragments.

Question 25

CHARACTERISTIC OF ACID MODIFIED STARCH

Answer 25

* Develop lower molecular weight and lower pasting viscosity compared to native starch * Develop stronger gel upon cooling * Higher gel clarity ✓ Widely used in manufacture of gum candies and other softeating confectionery. ✓ Could form concentrated gels that set firmly upon cooling

Question 26

OXIDIZED STARCH

Answer 26

Starch treated with oxidizing agents, such as sodium hypochlorite.

Question 27

OXIDATION PROCESS

Answer 27

introduces carboxyl and carbonyl groups into the starch molecule, altering its functional properties.

Question 28

The introduction of carboxyl and carbonyl groups causes

Answer 28

partial depolymerization of the starch, leading to a reduction in molecular weight and viscosity

Question 29

* Oxidized starch is widely used in the food industry due to its unique characteristics,

Answer 29

including lower viscosity, improved film-forming ability, and enhanced binding properties

Question 30

APPLICATIONS OXIDIZED STARCH

Answer 30

Batters and Dough, Icings and Glazes, Gummies and Jellies, Crispy Coating

Question 31

α-amylase, β-amylase, glucoamylase, pullulanase

Answer 31

Enzymes hydrolyze (1→4) or (1→6) linkages between α-Dglucopyranosyl residues

Question 32

Hydrolysates with:

Answer 32

* DE < 20 : maltodextrin * DE 20 – 100 : Glucose syrup/corn syrup

Question 33

α- amylase is an endoenzyme that

Answer 33

hydrolyzed α-1,4 linkages producing linear and branched saccharide

Question 34

β-amylase is an exoenzyme that

Answer 34

hydrolyzed α-1,4 linkages at every 2 glucose unit, from non reducing end producing maltose and β-limit dextrin

Question 35

Glucoamylase can

Answer 35

hydrolyzed both α-1,4 linkages and α-1,6 linkages, producing glucose

Question 36

Dextrinization/Pyroconversion is the

Answer 36

e roasting of dry starch (10-20% moisture) at high temperature (200-250°C) in a small amount of acid (eg. HCl)

Question 37

crosslinked starch

Answer 37

Starch granules are treated with crosslinking agents such as phosphorus oxychloride, epichlorohydrin, sodium trimetaphosphate, or adipic anhydride

Question 38

crosslinking agents react with the hydroxyl groups on the starch molecules

Answer 38

forming covalent bonds between them, which results in a network structure

Question 39

crosslinked starch

Answer 39

Form bridges/crosslinks (covalent bonding) from one starch molecules to another; thus, strengthening the granules

Question 40

Characteristic of crosslinked starch

Answer 40

* The starch granules have increased resistance to swelling and gelatinization * A higher viscosity of the cooked starch paste is attained * Increase resistance of starch paste viscosities to the thinning effect of prolonged agitation, heat or pH Also known as PROCESS TOLERANT STARCH * Reduction of the cohesive, rubbery, elastic characteristic of starch paste - give smooth, creamy paste

Question 41

Application of crosslinked starch-1. Salad dressing -

Answer 41

provide thickening with stable viscosity at low pH and high shear during the homogenization process

Question 42

AApplication of crosslinked starch-Canned food

Answer 42

provide low initial viscosity, high heat transfer, and rapid temperature increase during retort sterilization

Question 43

Application of crosslinked starch-

Answer 43

Applied in soups, gravies, sauces, baby foods, fruit filling, pudding, and deep-fried foods.

Question 44

STABILIZED STARCH

Answer 44

* Also known as SUBSTITUTED STARCH

Question 45

In substitution/stabilization, bulky groups are

Answer 45

substituted onto the starch by either etherification or esterification

Question 46

ESTERIFICATION

Answer 46

the hydroxyl groups (–OH) present on the glucose units of starch molecules are converted into ester groups (–O–C=O) through a reaction with an acid or anhydride.

Question 47

Approved reagent for esterification

Answer 47

acetic anhydride, vinyl acetate, succinic anhydride, 1-octenyl succinic anhydride and sodium tripolyphosphate

Question 48

ESTERIFICATION - HYDROPHOBIC MODIFICATION

Answer 48

Application * Stabilization of carbonated beverage * Stabilizers in in high viscosity high oil systems, such as salad dressings * Encapsulation of water insoluble substances, both volatile and nonvolatile

Question 49

ETHERIFICATION –Hydroxypropylated starch

Answer 49

the hydroxyl groups (–OH) of the glucose units in starch are converted into ether groups (–O–R) through a reaction with alkylating agents.

Question 50

etherification application

Answer 50

thickeners in fruit pie fillings, puddings, gravies, sauces, salad dressings and frozen pudding