Food Science

Question 1

Name 3 reasons why we cook food?

Answer 1

Give variety to the diet
Kills bacteria
Develops flavour
Improves texture
Improves shelf life

Question 2

Name the 3 types of heat transfers

Answer 2

Convection, conduction and radiation

Question 3

What’s radiation?

Answer 3

Energy transferred by waves of heat and light.

e.g infrared and microwave

Question 4

What’s conduction?

Answer 4

Movement of heat through a substance by the collision of molecules
e.g shallow frying

Question 5

What’s convection?

Answer 5

Heat traveling through air and water

e.g poaching

Question 6

Name the functional & chemical properties of carbohydrates

Answer 6

Gelatinisation, dextrinisation and caramelisation

Question 7

What’s gelatinisation?

Answer 7

Thickening process in foods that occurs between 75 and 85 degrees e.g sauce

Question 8

What does amylose do?

Answer 8

Thickens the mixture and makes it cloudy and thicker when cool

Question 9

What does amylopectin do?

Answer 9

Makes the sauce clear & the same thickness when cool

Question 10

What can effect gelatinisation?

Answer 10

Starch used
Temperature
How long they stirred
Sugar
Acids

Question 11

What’s dextrinisation

Answer 11

Happens when starch is broken down into dextrin

e.g bread

Question 12

What does dextrinisation do?

Answer 12

Adds a sweet taste and contributes colour and flavour to food

Question 13

What’s caramelisation?

Answer 13

Browning process in sugar. White - brown.

e.g creme brûlée

Question 14

What does caramelisation do?

Answer 14

Changes flavour, golden brown colour & adds a buttery, nutty & toasty flavour

Question 15

What are the functional and chemical properties of protein?

Answer 15

Denaturation, coagulation, gluten formation & foam formation

Question 16

What’s denaturation?

Answer 16

Change of structure in protein. Amino acids unfold from their coiled state

Question 17

What are the 3 ways that protein can be denatured?

Answer 17

Mechanical - whisking
Acid - marinating
Heat - cooking

Question 18

What is coagulation?

Answer 18

Setting process in foods

e.g egg

Question 19

What happens when heated to much?

Answer 19

Becomes hard, tough & difficult to digest. Syneresis - over coagulation
e.g scrambled egg

Question 20

What’s gluten formation?

Answer 20

Formation of gluten

e.g bread

Question 21

What does glutenin do?

Answer 21

Gives dough strength & elasticity

Question 22

What does gliadin do?

Answer 22

Binds the dough together

Question 23

What’s foam formation?

Answer 23

Formation of foam. Produces gas in a liquid allowing tiny bubbles of air to be incorporated into the egg
e.g whisking eggs

Question 24

What are the functional & chemical properties of fats

Answer 24

Shortening, aeration, plasticity & emulsification

Question 25

What’s shortening?

Answer 25

Fat coating flour particles giving a waterproof coating & prevents the absorption of water. Gives food a short and crumbly texture. e.gshortbread

Question 26

What’s aeration?

Answer 26

When air is trapped in a mixture. Tiny bubbles of air enclose in the mixture giving a springy light texture e.g cake

Question 27

What’s plasticity?

Answer 27

Ability of a solid fat to melt over a range of temperatures. e.g melting butter Effects spreading, creaming & shortening ability of fat

Question 28

What’s emulsification?

Answer 28

When 2 unmixable liquids are forced together do tiny droplets of one mix with the other e.g mayonnaise

Question 29

What’s an oil in water emulsion?

Answer 29

More water than oil in a mixture

Question 30

What’s a water in oil emulsion?

Answer 30

More oil than water in a mixture

Question 31

What’s an emulsifier?

Answer 31

Forces 2 unmixable liquids together

Question 32

Name cooking methods that use dry heat. Give an example and heat transfer

Answer 32

Grilling - bacon -radiation Dry frying - bacon - conduction Baking - cakes - convection Barbecuing - conduction -sausages

Question 33

Name cooking methods that use water/steam. Give example and the heat transfer.

Answer 33

Poaching - convection - egg Boiling - convection - potatoes Blanching - convection - vegetables Stewing - convection - steak

Question 34

Name cooking methods that use fat. Give examples and what heat transfer is used.

Answer 34

Stir frying - conduction - noodles | Shallow frying - conduction - bacon

Question 35

What is a raising agent?

Answer 35

Something that makes a mixture rise by putting co2 in the mixture

Question 36

Name the mechanical raising agents

Answer 36

``` Beating - batter Creaming - cake Rubbing in - pastry Sieving - scones Whisking - meringues Folding - flaky pastry ```

Question 37

What is a mechanical raising agent?

Answer 37

Uses air & steam. The steam is produced during cooking from liquids in the mixture

Question 38

What is a chemical raising agent?

Answer 38

Produces CO2 when heated with a liquid

Question 39

Name the 2 types of chemical raising agents

Answer 39

Bicarbonate of soda - co2 produced when heated which forms small bubbles - soda bread Baking powder - mixture of 2 chemicals which react with moisture & heat which creates CO2 - small cakes

Question 40

What’s a biological raising agent?

Answer 40

A living plant | e.g yeast

Question 41

Name the 3 types of yeast

Answer 41

Fast acting, fresh & dried

Question 42

What’s fermentation?

Answer 42

When heat produces CO2

Question 43

Name the 3 ways of which fermentation happens

Answer 43

Warmth - 25-29 degrees to activate Food - gives it energy to activate Liquid - water / milk helps it to form

Question 44

Give an example of a biological raising agent

Answer 44

Yeast

Question 45

what is boiling

Answer 45

+healthy - water soluble vitamins maybe lost +uses less energy -not as tasty or attractive as other cooking methods meats, potatoes, pasta and rice are boiled involveer heating food in a pan of boiling liquid

Question 46

what is steaming

Answer 46

+keeps taste, texture and colour +keeps more nutrients -don't have as much flavour than if other methods were used fish, rice and veg are steamed cooking food with steam

Question 47

what is blanching

Answer 47

+preserves colour, texture and vitamins +removes harsh flavours and makes skins easier to remove fruit and veg are blanched part cooking food in boiling water for a very short time before putting it in cold water

Question 48

what is simmering

Answer 48

+preserves more nutrients soups and curries are simmered when food is cooked at a slightly lower temperature than boiling point

Question 49

what is poaching

Answer 49

+makes food more tender +absorbs favours and gives variety to diet. - nutritional content and tastiness is lowered eggs, fruit and fish are poached cooking food in a pan of liquid before boiling point (80)

Question 50

what is braising

Answer 50

slowly cooking food in an oven proof pot that has the lid on containing liquid meat and veg are braised +tenderises meat, caramelised flavour is given absorbs flavour

Question 51

what is stir-frying

Answer 51

food cooked in a wok with a small amount of oil added noodels, veg, meat, fish +keep more nutrients, healthy

Question 52

what is shallow frying

Answer 52

food cooked in a frying pan voted in a medium amount of oil meat, fish, eggs, pancakes -less healthy +crispy texture given

Question 53

what is baking

Answer 53

baking uses convection and uses dry heat to cook food in an oven bread, pastries, cakes, pies

Question 54

what are the advantages of baking

Answer 54

healthy, make sit look and taste nice, wide variety of food can be cooked this way

Question 55

what are the disadvantage of baking

Answer 55

takes a long time, food can become dried out, uses a lot of energy

Question 56

what is grilling

Answer 56

uses radiation and dry heat to cook food at a high temperature veg, cheese, meat

Question 57

what are the advantages of grilling

Answer 57

quick, healthy, looks and taste nice, gives smoke flavour and crispy texture

Question 58

what are the disadvantages of grilling

Answer 58

hard to cook evenly, easy to burn, easy to cross contaminate

Question 59

what is roasting

Answer 59

when fat is added to the outside of food snd cooked at high temperature using dry heat meat, veg, potatoes

Question 60

what are the advantages of roasting

Answer 60

brown and crisp food, moist, can produce best with a rare centre

Question 61

what are the disadvantage of roasting

Answer 61

not healthy, takes a long time

Question 62

what is dry frying

Answer 62

cooking food in a pan without fat and oil | minced meat, bacon nuts, seeds and spices

Question 63

what are the advantages of dry frying

Answer 63

healthy, gives distinct aroma

Question 64

what are the disadvantages of dry frying

Answer 64

takes a long time, can only b used for a small range of food