CHEMISTRY 1

• Additives make food last longer and taste better
  • Food colours make food look more appealing
  • Flavour enhancers bring out the taste and smell of food

• Antioxidants stop foods reacting with oxygen
  • When foods react with oxygen, they go off, such as butter going rancid or apples going brown
  • Antioxidants stop food containing fat or oil reacting with oxygen in the air

• Emulsifiers help oil and water mix
  • When oil and water mix, it forms an emulsion, although emulsifiers must be added or they separate
  • Emulsifiers are molecules with one part that's attracted to water (hydrophilic head) and one part that's attracted to oil (hydrophobic tail)

• Foods are cooked because it can:
  • Make them taste better
  • Make them easier to digest
  • Make them safer to eat (by killing off bacteria)
• Potatoes:
  • Cooking potatoes breaks down the cell walls, which are made of cellulose
  • This makes it easier to digest as human's cannot digest cellulose well
• Eggs and Meat:
  • Cooking them breaks chemical bonds in the protein, changing the shape of the molecule
  • This gives the food a more edible texture, and is called denaturing
• Baking Powder:
  • Undergoes thermal decomposition when heated

Sodium hydrogencarbonate -> sodium carbonate + carbon dioxide + water