Functional Properties Of Food

Question 1

Denaturation of globular proteins?

Answer 1

It denatures very easily and is visible.

Eg. Adding lemon juice to milk changes the texture of the milk

The foam created when beating egg whites is a visible sign

Question 2

Denaturation of fibrous proteins?

Answer 2

It is less visible and a lot stronger

Eg. Tough cuts of meat are often marinated in acid ingredients to make it more tender

Question 3

What is coagulation?

Answer 3

When a protein separates from other nutrients turns from a liquid to a solid
Eg. Mixtures containing gelatin thicken when call.

Question 4

What is gelation?

Answer 4

The process of gel formation

Question 5

How does gelation occur in proteins?

Answer 5

When tiny droplets of liquid are trapped within coagulated proteins, forming soft, elastic such as custard and cheese.

Question 6

What is foaming?

Answer 6

Egg white foam consists of air bubbles surrounded by denatured protein

Question 7

Why does browning occur with proteins?

Answer 7

Foods containing protein turn brown during protein for three reasons-

oxidation, application of heat and the Maillard reaction.

Question 8

How does gelatinisation of starch occur?

Answer 8

Starch can thicken mixtures by absorbing liquid in the presence of heat.
Eg. Wheat flour, corn flour and arrowroot

Question 9

How does dextrinisation occur?

Answer 9

The process in which starch breaks down into dextrins

Eg: when bread is toasted.

Question 10

How do dextrins work?

Answer 10

The polysaccharide starch can undergo a partial chemical breakdown into shorter glucose chains called dextrins.

Question 11

What is crystallisation?

Answer 11

Functional property of sugar related to its ability to dissolve and reform crystals.
Eg: toffee, brittle, fudge.

Question 12

The role of fats in emulsification

Answer 12

Lipids do not mix naturally with water, when they do this process is called emulsification.

Question 13

How does homogenisation work?

Answer 13

Homogenisation is an emulsifying process that distributes lipids even throughout a liquid.

Question 14

Aeration of fats

Answer 14

Aeration occurs when air is added to a mixture, affecting its consistency and texture.

Eg. Creaming butter, ‘rubbing in’, whipping cream to form a foam.

Question 15

The role of proteins in denaturing?

Answer 15

Denature occurs when the bonds holding the helix shape are broken and the strands of the helix separate

Question 16

How do lipids digest?

Answer 16

Bile is produced in the liver but is stored in and released from the gall bladder.
It acts as a detergent to emulsify lipids.
Lipases break them into glycerol and fatty acids which are then absorbed through the ileum wall.

Question 17

What is a complementary protein?

Answer 17

A mixture of incomplete proteins that complement each other
Eg: rice with peas or lentils
Bread with peanut butter
Corn tortillas with kidney beans

Question 18

Why do you need calcium?

Answer 18

Food sources- dairy products, sardines and salmon, green veggies, nuts like almonds
Calcuim absorption may be reduced when a meal is high in lipids

Similarities

Question 19

Why do you need calcium?

Answer 19

Food sources- dairy products, sardines and salmon, green veggies, nuts like almonds
Calcuim absorption may be reduced when a meal is high in lipids

Similarities

Question 20

What is caramelisation?

Answer 20

The removal of water in sugar (glucose or sucrose) which then causes a browning reaction

Question 21

Calcium and phosphate:

Answer 21

Calcium and phosphate provide calcium phosphate in a network of bone cells