Chapter 14 - Heat Transfer and Methods of Cooking Flashcards
Name two methods of cooking and give one example of the use of each method in the preparation of meals.
● Dry-heat cooking [E.g Grilling a chicken]
● Moist-heat cooking [E.g Boiling eggs]
● Cooking in hot-fat [E.g Stir-fry vegetables]
Explain the reasons for cooking food and give one example to illustrate each reason.
● Cooking kills microorganisms, making food safe for consumption. [E.g Raw food such as meat and seafood need to be cooked to remove microorganisms.]
● Cooking food reduces bulk, making them easier to chew and digest. [E.g Fibres in green vegetables are bulky and have to be softened and the bulk reduced with cooking.]
● Taste and flavour of food is improved [E.g Flour in cakes and bread tastes unpleasant when it is uncooked.]
● Cooking adds variety to food. [E.g Eggs can be boiled, scrambled, poached, baked or steamed.]
State the advantages of the baking method.
Healthy method of cooking as little/no oil is used, food becomes soft and digestible, little loss of nutrients, useful for cooking large quantities of food, does not require constant attention.
State the advantages of microwave cooking.
● Microwave are a healthy method of cooking that
uses little or no oil.
● Quick method of cooking.
● There’s little loss of nutrients
● Useful for reheating and thawing of food.
● Does not require much attention
● Does not require much cleaning.
State the disadvantages of microwave cooking.
● Microwaving does not make food become crispy or brown.
● Food may dry out if cooked for too long.
● Also important to know cooking time and instructions must be followed for food to cook properly and thoroughly.
State the advantages of steaming.
● It is a healthy method of cooking that uses little or no oil.
● Food becomes soft and digestible suitable for all groups of people.
● There is little loss of nutrients or flavor from the food.
● Soft food does not break apart easily.
● Economical as many types of food can be cooked at the same time by using a tiered steamer.
State the disadvantages of steaming.
● some food takes a long time to cook;
● heat destruction of vitamin C more likely to occur;
● food does not develop colour / does not look
attractive;
● food can be insipid / tasteless so needs to be served
with a sauce;
● food remains soft / not crisp / variety of texture /
lacks “bite” / needs additional accompaniment to
vary texture
State the advantages of frying.
● Frying is a quick method of cooking.
● There is little loss of nutrients when cooked at the correct temperature.
● Batter-coated when deep fried helps to prevent loss of nutrients.
● Food becomes crispy and tasty. Desirable golden brown colour is seen on surface of food.
Explain what is dry-frying.
● Cooking food in its own fat without any added fat or
oil.
● When food is heated, the fat melts and runs out from
it, cooking the food in its own fat.
● Food such as bacon and peanuts contain significant
amounts of fat and are suitable for dry-frying.
● Heat is transferred to the food through conduction.
Explain what is shallow-frying.
● Cooking food by partially submerging food in hot oil
covering the base of the frying pan.
● The food has to be turned over to ensure both sides
are cooked.
● Food such as cutlets, fish and finger food are suitable
for shallow-frying.
● Heat is transferred to the food through convection
and conduction.
Explain what is deep-frying.
● Cooking food by immersing it completely in hot oil.
● Oil must be very hot (180 degrees - 205 degrees) before frying.
● Heat is transferred to the food through convection.
● Food coated with batter are usually deep fried. The
coating protects the food from falling apart.
State the disadvantages of deep-frying.
● Requires skill & must be carefully done because the
splattering hot fat can be dangerous.
● Needs constant attention, dangerous method of
cooking, if overheated could cause fire such as for
deep frying.
● Large amount of oil required for deep-frying-can be
expensive.
● Cannot cook large amounts at once.
● If the fat is too hot food will be overcooked on the
outside and raw inside.
● If the fat is too cool food will absorb oil. It will
become soggy / unappetising.
● Must strain oil when cool to remove crumbs of food
which can decompose and give a bitter flavour /
leave dark specks on food.
Name one method of heat transfer which takes place during baking.
● Convection
● Radiation
[Accept any 1 of the above answers]
Explain what is convection.
● Heat is transferred by the movement of a liquid or
gas.
● As the liquid / gas heats up, the hotter portion of the
liquid / gas rises and cooler portion sinks to the
bottom, forming a type of circular movement known
as convection currents.
Explain what is radiation.
● Heat travels from one point to another in the form of
energy waves known as infrared rays or
electromagnetic waves.
● Does not require a medium such as air or water to
transfer heat.
● When infrared rays fall on food, the heat is absorbed
and the food gets cooked.
