why food is cooked

• different cooking methods change our food in different ways - these include changes to sensory properties (appearance, texture, flavour and smell) and changes to nutritional value
• to make it safe to eat:

  • many food sources (including meat, poultry and eggs) can contain harmful bacteria that can make us ill. bacteria can be killed if food is cooked long enough at a high temperature
  • some foods contain harmful toxins that are destroyed when the food is cooked - eg red kidney beans have to be soaked, boiled and simmered before they are safe to consume
• to improve shelf life:

  • when foods are cooked at high temperatures, bacteria and mould are destroyed
  • this is one of the ways that food can be preserved during the manufacturing process
  • eg milk is pasteurised to help it stay fresher for longer
• to develop flavours:

  • chemical reactions take place during cooking that change the flavour of the food eg caramelisation can occur when onions are cooked, making them taste sweeter
  • roasting meats and vegetables creates more intense flavours. the food becomes browner and crispier with more fat added to it as water evaporates from inside the food
  • cooking also allows the flavours of different foods to combine, eg when braising a meat in a pot of liquid and veg
• to improve texture:

  • cooking usually makes it easier for us to chew, swallow and digest our food
  • some foods become softer when cooked - eg vegetables like broccoli and carrots become more flexible and foods like rice and pasta swell and their starch molecules soften
  • meats become tough and egg whites rubbery if they are overcooked
  • a change in texture can make food more pleasant to eat eg baked bread has a light textured inside but a crusty outside
• to give variety in the diet:

  • foods can be cooked in different ways to create variety
  • for example beef can be cooked as grilled steak, roast beef, pan fried minced beef or barbecued burger