Food science

Question 1

What is shallow frying?

Answer 1

A pan with a moderate amount of fat or oil is heated to a high temperature

Question 2

What is stir frying?

Answer 2

A fast method of cooking food at a high temperature with a small amount of oil

Question 3

What are examples of shallow frying?

Answer 3

Cuts if the meat like bacon, sausages, vegetables, fish, steak

Question 4

What is the nutritinal effect of Shallow frying?

Answer 4

Can be a quick method of cooking, helping to retain vitamins and minerals. May increase the fat content of the meal

Question 5

Whats the effect of Shallow frying?

Answer 5

Browns the food and gives it a crispy texture

Question 6

What are examples of stir frying?

Answer 6

Meat, poultry, shelfish, vegetables, noodles

Question 7

What are the nutritinal effects of stir frying?

Answer 7

Vitamins, minerals and antioxidant values are retained

Question 8

What’s the effect of stir frying?

Answer 8

Fresh and visually appealing as the colour and texture of the food is retained

Question 9

What is coagulation?

Answer 9

Coagulation is a change of structure of the protein. The denatured and protein molecues join and change the texture and apperance of the protein food

Question 10

What is denaturation?

Answer 10

the unfolding or breaking up of a protein, modifying its standard three-dimensional structure

(to change by chemical or physical means breaking the chemical bons)

Can be denatured by heat, mechanical action, or using acid in marinating

Question 11

What are the effects of heat on protein?

Answer 11

Eggs - When an egg is heated, the whites change colour and becomes solid

Meat - As the meat is heated, it changes colour and the fibres lose water and shrink, if cooked for too long it becomes chewy.

Question 12

What does heat and acid do to the proteins?

Answer 12

It changes shape and structure of the protein permanemtly
Example - Egg whites, turns into a foam when whisked

Question 13

What does an acid do?

Answer 13

It denatures protein and help tenderise meat. Adding immersing foods in citrus juice , vinegar, wine, beer or yoghurt with other seasonings also adds flavour and keeps it moist
Example - Turning milk into cheese

Question 14

What is gluten?

Answer 14

Gluten is a structual protein, it is developed by kneading, which strengthens and lengthens the gluten strands, the dough becomes strechy and elastic meaning it can change shape

Hard wheat has a high protein content, good quality gluten makes strong flour, soft wheat has a lower gluten content and is used to produce plain and self-rasising flour.

Question 15

What is agitation?

Answer 15

It is when you mix it or stir it, knead

Question 16

What is an example of agitation or mechanical action on protein?

Answer 16

An example is whiksing and egg, the protein stretches as the molecues unfold and form a mesh to trap bubbles of air, this eventually forms a foam

Question 17

What is a foam formation?

Answer 17

Foams are formed when gases (mainly air) are trapped inside a liquid, for example whisking an egg - the more its whilsked the stiffer it gets and will stand in soft peaks

Question 18

What is Gelatinisation?

Answer 18

Geletinsation is where chemical reaction where starch thickens in presence of moisture and heat

Examples - potatoes, rice, pearl barley, pasta, and some sauces

Question 19

What is a amylose and amylopectin?

Answer 19

Two types of starch molecues densely packed together

Question 20

What is caramelisation?

Answer 20

Caramelisation occurs when carbohydrates such as sugar are heated, at high temperatures water evaporates and sugar begins to break down and turn brown

Different sugars caremelise at different temperatures, for example when sucrose is heated it melts down into glucose and fructose and begins to caremlise at 160*C

Question 21

What is dextrinisation?

Answer 21

It is the structual modification of starch that usually occurs in the presences of dry heat, when heated starches break down into sugars called dextrin. Dextrin is brown which results in food turning golden brown when baked. It also changes the taste and smell of food

Example- Toast

Question 22

What is plasticity?

Answer 22

Plasticity is the ability to be spread and shaped

Question 23

What is shortening?

Answer 23

Shortening is a fat, solid at room temperature, which can be used to give foods a crumbly and crisp texture like pastry (the rub in method)

In shortening when the fat coats the particles of flour creating a barrier and limiting the gluten molecues from developing. When water is added the gluten strands can only form short lengths.

Question 24

What is aeration?

Answer 24

Aeration is the process of trapping tiny pockets of air into a mixture giving a well risen and light texture to bake goods liike cakes.

Question 25

What is creaming?

Answer 25

When fat and sugar are beaten together to make a smooth creamy texture

Question 26

What is emulsification?

Answer 26

It is the process of dispersing two or more immisible liquids together to form a semi stable mixture. An emulsion happens when small droplets of one solution are dispersed throughout another

Examples - Egg yolks, mustard, soy and guar gum are natural emulsifiers

Question 27

What is an immisible liquid?

Answer 27

A liquid that cannot be mixed with another liquid without not spearting

Example - oil and water

Question 28

What are hydrophilic and hydrophobic?

Answer 28

Hydrophilic is the part that is attratced to water

Hydrophobic is the part that isnt attracted to water

Question 29

what is a raising agent

Answer 29

Raising agents include anything that causes rising within foods, and are usually used in baked goods

examples: bicarbonate of soda, baking powder and self-raising flour

Question 30

Can you explain the difference between mechanical aeration and chemical aeration in food preparation?

Answer 30

mechanical: air is added by sieving the flour, creaming the fat and sugar, beating in the egg

chemical: aeration by baking powder and baking soda

Question 31

What is the purpose of chilling

Answer 31

helps stop harmful bacteria from growing

Question 32

How do physical changes, like the expansion of steam, contribute to the texture of certain baked goods?

Answer 32

The moist steam reinvigorates the yeast in the dough. Steam gives bread dough time to expand: the added moisture keeps the dough from drying out before it has time to rise.

Question 33

what is Pasteurisation

Answer 33

a process of heat processing a liquid or a food to kill pathogenic bacteria to make the food safe to eat and to preserve longer

examples: milk,

Question 34

what is Ultra heat treatment
UHT

Answer 34

a food processing technology that sterilizes liquid food, most commonly milk, by heating it above 135 °C over a very short time period

Question 35

what does sterilized mean

Answer 35

Put into special bottles and heated to 110°C for 30 seconds, Can be stored unopened for several months

Question 36

what is Homogenisation

Answer 36

a process by which the fat droplets from milk are emulsified and the cream does not separate