Chapter 6: Texture modification and Clinical Nutrition Applications

Question 1

What is gelatin derived from?

Answer 1

a protein derived from beef and pork bones and pork skin.

Question 2

What are plant based alternatives to gelatin?

Answer 2

agar flakes and carrageenan (from algae and seaweed)

Question 3

How should gelatin be prepared before adding it into a liquid

Answer 3

Gelatin should be softened in cold water before being dispersed into liquid. Otherwise it will clump. Or it can be dispersed in sugar

Question 4

What are the factors affecting gelatin setting power?

Answer 4

Gelatin concentration
Sugar
Acid
Salts
Physical Interference
Enzymes
Temperature and Time

Question 5

What is the minimum concentration necessary for gelling? (Gelatin Concentration)

Answer 5

15ml for 500ml of liquid

Question 6

How does sugar affect the gelatin setting power?

Answer 6

Sugar decreases gel strength by competing with water for binding sites on gelatin

Question 7

At what pH is a gel most rigid?

Answer 7

between a pH of 5-10 (gels are more tender when acidic)

Question 8

What happens when salt is added to a gel?

Answer 8

The presence of salt results in a firmer gel

Question 9

What will physically interfere with gel setting?

Answer 9

The presence of fruits or vegetable and mechanical agitation with interfere with bond formation

Question 10

What happens when fresh pineapple or kiwi are added in a gelatin mixture?

Answer 10

The gel will not set (the enzymes will denature the gelatin)

Question 11

What occurs when gelatin is boiled?

Answer 11

The gelatin loses its setting ability.

Question 12

Why should gelatin be cooled slowly and not rapidly?

Answer 12

The gel network forms quickly under cool temperatures. If cooled rapidly, weak gel forms with weak bonds. At room temp, gel will reliquify

Question 13

Define Emulsion

Answer 13

A dispersion of one liquid into another. (both liquids are mutually antagonistic or immiscible)

Question 14

How are emulsions classified?

Answer 14

Classified according to their degree of stability.

Temporary emulsion, semi permanent emulsion and permanent emulsion

Question 15

Temporary Emulsions

Answer 15

Thin viscosity and stability (ex. Italian dressing)

Question 16

Semi Permanent Emulsion

Answer 16

Viscosity similar to thick cream, higher degree of stability (ex. commercial salad dressings)

Question 17

Permanent Emulsion

Answer 17

Very thick viscosity (semi solid and are very stable (ex. mayonnaise)

Question 18

How are starches used in cooking? Give some examples

Answer 18

Used for thickening purposes. Examples include: wheat flour, tapioca, arrowroot

Question 19

How can clumps in a sauce be prevented? (ex. adding flour to a gravy)

Answer 19

By separating or dispersing the starch granules before liquid is added. (coating starch with fat, surrounding starch with sugar, dispersing in a small amount of cold liquid)

Question 20

When occurs when a starch and a liquid are mixed?

Answer 20

a small amount of water is absorbed producing reversible swelling of the starch granules

Question 21

When a starch and liquid mixture are heated,

Answer 21

more water is absorbed, swelling continues, starch granules soften. Starch grain lose their birefringence (molecular order). Further cooking completely gelatinizes the starch and thickens liquid.

Question 22

If a starch and liquid mixture are cooked for a long time

Answer 22

Pasting occurs: starch granules swell enormously, starch leaks our of the granule and evaporation of water. Starch paste loses raw flavour.

Question 23

If a starch and liquid mixture are overcooked/ over stirred

Answer 23

swollen starch granules rupture, mixture thins.

Question 24

When a starch paste cools..

Answer 24

Gels forms.

Question 25

True or False: The thickening power of a starch will diminish if not stored in an airtight container

Answer 25

True

Question 26

Syneresis

Answer 26

leakage or separation of a liquid from a gel occurs when a cooled gel has been sitting for a long period of time ( amylose molecules continue forming bonds, squeezes water out) Process quickens if gel is frozen

Question 27

Does sugar delay gelatinization

Answer 27

Yes, sugar competes with starch for water. In small amounts: tenderizes gels In large amounts: decreases gel strength

Question 28

How will dextrinized starch or acidic ingredients affect starch?

Answer 28

Decreases thickening power of starch.

Question 29

Pyrodextrins are formed when

Answer 29

starch is exposed to dry heat

Question 30

What are white sauces (bechamel) made out of?

Answer 30

Milk, thickened with flour dispersed in fat (roux). This method removes the raw starch taste and reduces potential clumps in the sauce.

Question 31

Veloute vs creamy veloute

Answer 31

veloute uses a white stock (poultry, fish or vegetable based) as the liquid. Addition of cream makes a creamy veloute.

Question 32

Mornay sauce contains

Answer 32

cheese

Question 33

What are brown sauces made out of?

Answer 33

made with brown roux and brown stock

Question 34

Do reduction sauces contain flour?

Answer 34

No, the water in the sauce is cooked off for a thicker consistency

Question 35

What base are pastry cream and pie fillings made out of?

Answer 35

Starch and egg- based

Question 36

What can be added into liquids for people with dysphagia?

Answer 36

Instant thickening agents containing modified pre gelationized corn starch.

Question 37

What disease can patients with dysphagia (swallowing disorder) easily contract?

Answer 37

Pneumonia

Question 38

What is the different between nectar, honey and pudding consistencies?

Answer 38

Nectar: thin, syrupy Honey: pourable Pudding: spoon needed

Question 39

What diets can be recommended for people with chewing or swallowing difficulties?

Answer 39

Pureed or blenderized diets

Question 40

Use of egg white foams?

Answer 40

making meringues, souffles, to obtain a light and porous texture.

Question 41

Does a copper bowl affect the formation and stability of egg whites?

Answer 41

Yes, volume and firmness of egg white foam is increased

Question 42

Is egg white foam easier to achieve with eggs at room temp or refrigerated eggs?

Answer 42

Room temperature eggs will reach a larger volume more quickly than refrigerated eggs, due to the lower surface tension of the warmer egg whites

Question 43

what is the difference between starches containing high amylose content vs. starches containing low amylose content during heating and cooling?

Answer 43

Starches containing a high amylose content: cloudy when heated and gel quickly when cooled Starches containing a low amylose content: transcluent when heated and will not gel as well. (will thicken due to amylopectin)