Page 7, cooking of food and heat transfer Flashcards
Why do we cook food, to make it safe to eat
Heat kills bacteria and parasites, inactivates harmful enzymes and toxins
Why do we cook food, to develop flavours
Water evaporation makes flavors more pronounced, sugar caramelization and other reactions change the initial flavor of the food
Why do we cook food, To improve texture
Cooking alters the texture of food products, making them easier to chew and more pleasurable to eat
Why do we cook food, To improve shelf life
Cooking kills microorganisms which could spoil the food, so it can be stored longer
Why do we cook food, To increase variety
One product may be cooked in many different ways, creating many different dishes from one product
Conduction
Direct transfer on heat from the saucepan to the food inside,
-Heat makes metal particles vibrate
-Vibrations of the metal are transferred to the particles of the food
-Food particles vibrate and the meal heats up
Convection
Indirect transfer of the heat through water or air
-Convection current makes the hot air / steam go up while the colder air falls
Radiation
Indirect transfer of heat through heat waves
-microwaves send electromagnetic waves, which heat up particles in the food
-water particles begin to vibrate and, therefore, heat up the whole meal
-Infrared radiation is used in grills and barbaques
Steaming
-water based method
-helps preserve nutritional value of food
-low in fat
Boiling
-water based method
-may cause vitamin loss
-low in fat
simmering
-water based method
-long time required
-low in fat
-causes vitamin loss
blanching
-water based method
-prevents enzymic browning and oxidation
-preserves nutritional value
Poaching
-water based method
-Ideal for preparing delicate ingredients
Braising
-water based method
-long time required
-causes vitamin loss
Baking
-dry method
-long time required
-causes vitamin loss
-good for cakes and other baked goods
Roasting
-dry method
-helps to reduce fat in food
-long time required
-decreases vitamin content
-helps to obtain a crispy skin or surface
grilling
-dry method
-may create harmful substances
-usually low in fat
Dry-frying
-dry method
-reduces amount of fat in food
-nutritional value is preserved
deep-frying
-oil based methods
-foods become golden and crunchy
-loss of vitamins
-high fat content
shallow-frying
-oil based methods
-seals the surface of foods and helps to obtain crunchy top and juicy interior
stir-frying
-oil based methods
-low in fat
-preserves nutritional value of food
