Food gcse aqa

• Some food to cook to make them digestible give two other reasons why we cook food?

  Make it safe to eat, to improve shelflife, to develop flavours, to improve texture.
• Why is freshly cooked hot food safe to eat?

  Cooking food at a high temperature destroys bacteria and mould that could spoil the food. As the food is freshly cooked, it has not had time to spoil yet so it will be safer to eat.
• What are the advantages and disadvantages of cooking raw vegetables?

  Cooking vegetables makes them softer and easier to chew. It can improve their flavour and make them more appetising and enjoyable to eat however cooking cam reduce their nutritional value for example vitamin B and vitamin C are lost when boiling and some cooking methods add fat for example deep frying or roasting.
• What is the name given to the transfer of heat through liquids and gases?

  Convection
• Name a piece of cooking equipment that uses radiation to transfer heat?

  Microwave
• Does frying grilling or poaching use convection?

  Poaching. frying uses conduction and grilling uses radiation
• How does a microwave heat up food?

  They use radiation. Heat energy is transferred by waves of energy hitting food.
• Does poaching cook food at higher temperature than boiling?

  No boiling is at 100° while poaching is usually around 80°
• Why is simmering used for a reduction sauces ?

  Simmering concentrates the flavour of a reduction sauce. It evaporates water which makes the flavour more intense because there is less liquid.
• Why can poaching lower the nutritional content of food more than steaming?

  Poaching cooks food and water so if the food contains any water soluble vitamins such as bee vitamins and vitamin C, it can lose these to the liquid. When there is no direct contact between the food and the water so the food will keep more of its nutrients.
• When shallow frying is heat transferred by convection?

  No, he is transferred by conduction when shallow frying
• What is a dry method of cooking?


  Grilling roasting
• Describe one food safety risk of grilling food.

  Food can be cooked or burn on the outside but still raw on the inside grilling raw and cooked foods on the same grill or barbecue could lead to cross contamination
• Give one benefit and one drawback of dry frying food.

  A benefit would be dry frying is a healthy frying method as it uses no extra fat dry roasting can improve the flavour and aroma of nuts seeds and spices.

  A drawback would be only a small range of foods can be dry fried as the food has to contain natural fat dry frying takes a long time because the temperature is low at the start.
• Why is strong flower preferred for bread making?

  Strong flour contains more gluten than other flower types giving the dough more elasticity
• Give one way you can agitate proteins

  Whisking beating or needing
• What is protein denaturaction?

  When chemical bond that hold a protein structure together irreversibly breakdown. The protein structures unravel and their shape changes.
• How does sugar change during caramelisation?


  Melting and browning.
• How does the process of gelatinisation thicken liquids?


  The bond between starch granules start to break as the liquid is heated allowing water molecules to enter the starch granulate swell in size and Steffen then burst open at around 80°. This releases starch into the liquid and causes it to thicken.
• Does saturated or unsaturated fats have more plasticity? Unsaturated fats
• Why does shortcut pastry have a firm and crumbly texture?

  Because the pastry is made by rubbing fat and flour together the flower particles are covered with the fact creating a waterproof coating. This prevent long strands of gluten forming in the dough when water is added this means the dough doesn’t become stretchy and gives the pastry of firm and crumbly texture when baked.
• What makes mayonnaise a stable emulsion?

  The egg yolk in mayonnaise contains an emulsifier. The emulsifier holds the oil and water in the mayonnaise together and stops them separating naturally.
• Two ingredients found in baking powder?

  Bicarbonate of soda and cream tartar
• Describe how biological raising agent raises bread dough

  Fermentation. Fermentation releases carbon dioxide which makes the bread rise when the dough goes into a hot oven fermentation stops as the yeast is killed the heat expands the gas trapped in the dough which makes the bread rise further