Methods of cooking
Radiation
Name two cereal products.
Noodles, pasta, cakes, pastries, biscuits
Name two products made from milk.
Cheese, yoghurt, cream, butter
Name the microorganisms responsible for food spoilage.
bacteria
mould
yeast
Baking (hot air), Boiling (hot water), Steaming (hot vapour), Deep/Shallow frying (hot oil)
1. Check that expiry date is still valid for consumption.
2. Check to make sure there is no weevil or tiny worm in cereal.
3. Avoid buying cereal with powdery residue as it may have been kept for a long time.
4. Do not buy whole-grain in bulk as they turn rancid quickly.
HOW
1. Wrap cheese in cling wrap film.
2. Place in a air-tight polythene bag.
WHERE
1. In chiller
2. Away from other foods to prevent cheese odour being absorbed by them (e.g. eggs, milk)
Which enzyme is responsible for enzymatic browning?
Polyphenol oxidase.
State four reasons for cooking foods.
1. Cooking makes food safe to consume by killing microorganisms.
2. Cooking makes food easier to chew, swallow and digest.
3. Cooking improves flavour and appearance of food.
4. Cooking adds variety to the diet.
5. Cooking makes food last longer.
Explain why wholegrain cereal is more nutritious than refined cereal.
Wholegrain cereal contains germ and bran that has fats, fat-soluble vitamin E, minerals iron and phosphorus, and dietary fibre that improves digestion. Whereas refined cereal does not contain germ and bran as they are removed during processing which cuts down on nutrient value.
Describe what happens to cheese when it is cooked.
1. Fats melt and cheese becomes soft.
2. Proteins in cheese coagulates, making cheese tough and stringy.
Explain how canning preserves food.
Food is heated to very high temperature in a pressurised environment, which kills off microorganisms.
State four disadvantages of microwaving.
1. Easy to overcook foods due to poor timing.
2. Food does not crisp up.
3. Food does not develop characteristics flavour, colours or textures.
4. Irregular-shaped food may affect cooking time and finished result of foods cooked on the same plate.
5. Only microwavable materials can be used which is a limitation.
6. Foods that are whole e.g. egg/potato cannot be microwaved as they can explode.
State three advice how to store cereals for freshness.
1. Keep wholegrain cereals in air-tight container and in the chiller to prevent rancidity of fats present in germ.
2. Avoid mixing new batch of cereals from old batch, store them separately in air-tight container in cool, dry place.
3. Keep cereals away from strong sunlight and strong smelling foods like onions and cheese as the cereal will tend to absorb them.4.
Suggest three ways to make cheese more digestible during cooking.
1. Grate or chop cheese into smaller pieces.
2. Cook cheese with starchy foods like bread so that melted fats are absorbed by starch granules.
3. Add cheese last during cooking to prevent over-coagulation of protein.
Name the hormone that speeds up ripening and ageing process in fruits.
Ethylene.
2. Boiled broccoli would retain its moistness while microwaved broccoli would be dried up as water evaporates.
Explain three factors when choosing flour for making bread.
1. Check that flour has higher protein content as it contains more gluten needed to give trap air and form structure of bread.
2. Choose white flour over wholemeal flour as white flour has better baking quality to produce finer textures.
3. Choose hard flour that is able to stretch and withstand the handling during bread-making process.
1. Pasteurisation - Heating milk to 72 degC for 15s, then cooled down rapidly.
2. Sterilisation - Heat milk to 115 degC for 15-20mins, then cooled down.
3. Ultra-high temperature (UHT) - heated to 132 degC for at least 1 sec, then packed in sterile containers.
Suggest how you would prevent enzymatic browning of fruits.
1. Soak cut fruits into sugar/lemon juice or salt water to prevent oxidation from happening.
2. avoid storing fruits in close environment which speeds up ripening process as ethylene is concentrated in the closed environment.