Why we cook foods Methods of cooking Cooking proteins Raising agents

Why do we cook foods? We cook foods for a number of reasons. Some of them are: microbesTo kill harmful microbes that may cause food poisoning digestTo make the food easier to digest flavourTo improve the flavour of the food textureTo improve the texture of the food

How can we cook foods? There are several ways to cook foods. Baking and roasting In an oven. Hot air surrounds the food Cakes, meat Boiling In boiling water. Vegetables can lose vitamins Eggs, potatoes Steaming In steam above water. Maintains vitamins. Vegetables, fish Frying In hot oil Chips, eggs Grilling Under a grill. Food is heated by direct radiation Steak Microwaving Uses waves to cook the food Fish, ready meals

Cooking Proteins Eggs appearance Eggs are a good source of proteins. We know it is a chemical change because the appearance changes. denatured When you heat up proteins, the molecule changes shape. We say is has been denatured.

Raising Agents rises When we make a cake it is important it rises. We add a raising agent. sodium hydrogen carbonate Baking powder is a raising agent which contains sodium hydrogen carbonate. decomposes When it is heated it decomposes (breaks down) Sodium Hydrogen  Sodium + Water + Carbon Carbonate Carbonate Dioxide 2 NaHCO 3  Na 2 CO 3 + H 2 O + CO 2