Behaviour Changes in Food

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  • Created by: Becky
  • Created on: 01-03-13 09:31

The basic ingredients for bread making:

  • Strong plain flour, yeast and water
  • During the initial stages of bread making, ingredients are mixed together and yeast is dispersed
  • Small quantitiy of sugar may be added to speed up fermentation
  • Salt is added to give the bread flavour
  • During mixing stage, water hydrates the flour particles and starts the process of gluten development
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The process of Kneading:

  • Process of kneading applied to mixture of flour, sugar, yeast, salt and water
  • The flour contains gliadin and glutenin proteins- when kneaded, form strands of gluten
  • Gluten= important structure of bread
  • If dough not sufficietly kneaded, it will not be able to hold the tiny pockets of caron dioxide created by the yeast
  • Kneading warms and stretches gluten strands
  • Eventually creates springy, elastic dough
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After kneading:

  • Dough is left in a warm place in order to ferment
  • Fermentation is the process in which stacrh is broken down by the yeast to producs alcohol and carbon dioxide
  • Flour conains an enzyme called diastase, which changes the starch into maltose, a type of suagr
  • The yeast contains many different enzymes including maltase, which changes maltose into the simpliest form of sugar glucose.
  • Yeast also contains enzyme zymase, which turns the glucose into carbon dioxide and a little alcohol
  • Carbon Dioxide allows the dough to rise
  • Fermented dough should double in size
  • In a warm environment (25) the rising temp. will be fast and in cooler environment (5), it could take hours
  • Over fermented dough will cause the gluten strands to stretch too much and lose some of elasticity
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More kneading:

  • Next stage involves more kneading
  • Usually called knocking back
  • Large bubbles of carbon dioxide produced from the action of zymase during the first rising need to b evenly spread throughout the dough
  • Gives the dough an even texture
  • It redistributes the nutrients for the yeast and allows fermentation to continue
  • Dough in then shaped and can be left to prove
  • Proving/ rising this time should be at 27 degrees for the yeast to function
  • Dough will rise again
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Final stage:

  • Baking the bread- hot oven
  • Will rise rapidly as carbon dioxide is produced by yeast
  • At 54 degrees, the yeast is killed and all enzymic reaction stops
  • As temp. continues to rise, starch gelatinises and gluten coagulates at 80 degrees
  • Water turns to steam and contributes to texture and volume
  • Action of dry heat on surface of bread is called maillard reaction, a form of non- enzymic browning
  • Combination of protein and starch causes the development of dextrin- type of sugar that gives golden colour
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