Protein

• • Protein molecules are often folded into compact bundles so they take up less space
  • Protein contains complex molecules which contain oxygen, carbon, hydrogen and nitrogen

  
• Denaturation is the breaking of the chemical bonds in protein which cause the protein to unfold and change shape
• Examples of denaturing proteins are:

  • adding acids
  • trapping air bubbles
  • mechanical agitation
  • heat
• Syneresis is when protein molecules coagulate too much, squeezing out the water they were once holding

  e.g: dry and chewy meat, rubbery and chewy scrambled egg
• Coagulation is when denatured protein molecules join together and trap water in the presence of heat. It is irreversible and changes the colour, texture and flavour of the food
• Strong plain flour is used for bread making as it has a high amount of gluten
• When a liquid is added to flour, it forms a gluten network called gluten
• Flour contains gliadin and glutenin
• Gluten gives dough the ability to be stretched and shaped during kneading and also makes it elastic
• When baked the gluten network in the dough traps the carbon dioxide bubbles, forming the soft and light texture and making it rise
• Example

  When making swiss roll, whole eggs and sugar are whisked together to make a whisked sponge mixture. They product a thick gas from trapping air pockets which produces a light spongy texture