1. Year 9 Food Function Explanation Ingredients Browning
Sugar CARAMELISES in moist heat or DEXTRINISES in dry heat.
Fat on meat browns in dry heat
Sugars, syrups, naturally sweet foods like fruit
Glazing
To make something go shiny, usually by putting it on top of the food before cooking in the oven.
Egg, milk, oil
Aeration/Aerating
Trapping air in a mixture to make it lighter
Eggs, Sugar and fat together, cream
Setting
To make a liquid go solid
eggs when heated, gluten in flour (coagulation) Gelatine (gelation)
Gelatinisation
To make a liquid become solid or set by heating starch in a liquid. This makes the starch grains swell and burst to thicken and set when cool.
Sauces. Jelly
Fortification (Enriching)
To add another nutrient into a mixture
Egg for protein, fresh fruit/vegetables for vitamins.
Foaming
To trap air in a liquid
Egg white, oil and water
Stiffening
To make the mixture firmer
Cornflour
Flavouring
To add an extra flavour
Raising
To make a dough mixture rise
Baking powder, Bicarbonate of soda, yeast
Thickening
To make a mixture less runny
Flour and cornflour
Emulsification
To mix oil and fat together e.g. in mayonnaise
Egg yolk
Sweetening
To make a mixture taste sweeter
Sugars, fruit juices, some vegetables (carrots, beetroot, parsnips)
Seasoning
To bring out extra flavour
Salt, pepper, mustard
Spicing
To increase the heat of a food
Chilli pepper
Fermentation
To produce carbon dioxide gas by the use of micro-organisms
Yeast in bread
Bacteria in yoghurt.
Shortening
Make something more melt in the mouth
Fats and eggs in pastry and biscuits.
Binding
Sticking together
Egg, water, milk
Coating
Putting a layer on top/round a food
Egg and breadcrumbs, flour, sugar strands.

2. Function in the body – growth and repair in the body
CARBOHYDRATES
STARCH
Flour is high in starch
Corn flour and arrowroot are pure starch
USES
Bulking agent – flour is often the main ingredient in many food products. The starch forms the main structure of the product e.g. pastry.
Thickening agent – raw starch tastes floury and needs to be cooked. When starch is heated in liquid, the walls of the starch become soft and hollow and allow liquid to pass through them. This makes the granules swell until they burst. This process is called gelatinisation.
Gelling agent – after gelatinisation the liquid forms a gel. On cooling the gel solidifies. When reheated it goes back to a liquid e.g. custard where corn flour is used.
USES OF SUGAR
Preserves food. It creates unsuitable conditions for bacteria to grow e.g. in Jam.
Bulking agent. Gives the food texture e.g. ice cream and cakes.
Aerates. When sugar is beaten with butter or eggs it helps trap air to make cakes light.
Keeps food moist and extends shelf life.
Sweetens drinks and food e.g. coffee.
Flavour. It improves or changes the flavour by removing sour taste e.g. in tomato sauce.
Colour. When sugar is heated it turns golden brown. This is called caramelisation.
Stabilises whisked mixtures e.g. meringue because it strengthens the foam.
FATS AND OILS
Function in the body–Insulation and gives some energy
PROTEIN
Function in the body – growth and repair in the body
Saturated Fats
Mostly found in solid fats e.g. butter.
High in cholesterol compared to other fats.
Unsaturated Fats
Mostly found in fats that are liquid at room temperature.
Mainly in vegetable oils e.g. cooking oils
Less cholesterol than saturated fats.
Protein foods are made up of amino acids that are linked together like the links in a chain. When protein foods are heated the links in the chain change and this alters the structure of the food. Example – a raw egg can change depending on if it is fried, scrambled or boiled.
FUNCTIONS OF EGGS
Bind – bind dry ingredients. When heated the eggs hold the ingredients together e.g. burgers.
Coat/enrobe – the eggs act like a glue and hold dry coating to a surface.
Coagulation – setting a mixture to hold a firm structure e.g. quiche. Full coagulation happens at 70◦c.
Aerate – trap air when beaten e.g. cakes, meringue.
Glaze – they add colour and give products a shiny glaze e.g. pastry.
Thicken – the protein sets when heated e.g. custard.
Emulsify – eggs are used to stop oil and water separating; allowing an emulsion to form e.g. mayo.
FUNCTIONS OF FATS AND OILS
Required to aerate food. When fat is creamed with sugar it helps trap air.
Prevents lumps of flour forming in a sauce e.g. white sauce
Adds flaky texture to pastry. Fat helps to separate layers by creating steam
Shortens pastry to give it a crumbly texture
Acts as a cooking medium for roasting foods e.g. chicken
Extends shelf life of baked products by keeping moist.