Functional properties of food

Starch

• thickens a liquid by forming a suspension such as a sauce
• forms a gel when the suspension is heated, like adding cornflour to a custard powder and milk mix

Sugar

• flavours by sweetening
• colours by caramelising when heated
• aerates when beaten with a fat such as in a cake mix

Proteins

• can coagulate which is when a liquid becomes firmer, for example when an egg is heated
• can aerate a mixture, like whisking egg whites in a meringue mix

Gelatinisation- Gelatinization is the process whereby the starch particles absorb moisture, expand and become firm. This process starts at 140 degrees and is complete when the sauce becomes bubbly.

Elasticity- Elasticity is its ability to go back to its original shape, the gluten, which forms when the flour interacts with water, is what lends the dough the elasticity.

Shortening- The effect of adding fat to a floury mixture- giving a product a crumbly texture, when fat coats flour particles and stops gluten (particals) chains breaking up and creating a crumbly texture, with little elasticity.

Aeration-There are  5  ways in which  Aeration can be achieved in cake making-

1. Biological (panary, yeast ).
2. Chemical (baking powder).
3. Mechanical ( whisking and beating)
4. Physical ( lamination, steam )
5. Combinations of the above.

Emulsification- A mixture of two or more unblendable mixtures. 

Flavouring- Sweetening agent- A sugar substitute is a food additive that duplicates the effect of sugar in taste. Some sugar substitutes are natural and some are synthetic. Those that are not natural are called artificial sweeteners

Colouring- Margarine and buuter gives good coloure while lard lacks in colour.

Setting- Gelatine is a colourless and ouderless setting agent made from boiled bones skins and tendons of animals. 

Fermentation- uses yeast to convert carbohydrates into alcohol and carbon dioxide. In bread making, yeast is added to flour and water causing the dough to rise.

Fats

• shortens pastry (makes it more crumbly) by making it less stretchy
• can act as an emulsifying agent to stop two liquids from separating
• moistens a baked mixture such as a cake

Suspension- A mixture of two ingredients, one of which is finely diveded throughout the other.

Caramelising- Turn to caramel- A brown mixture which sugar turns to when heated to the point where all the water has been driven off and the sugar begins to burn. Aerates- Aerating mixes air into a material.

Coagulate- When somthing thickens from a liquid to a solid. eg raw eggs are clear and runny but turn white and stiff when heated.

Emulsifying agent- A substance which helps two liquids stay mixed together. eg. oil and water.