Behaviour Changes in Food 3.0 / 5 based on 1 rating ? Home EconomicsA2/A-levelOCR Created by: BeckyCreated 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 1 of 5 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 2 of 5 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 3 of 5 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 4 of 5 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 5 of 5
CCEA AS HOME ECONOMICS- NUTRITION ACROSS THE LIFE CYCLE 5.0 / 5 based on 1 rating Teacher recommended
Dioxins and polychlorinated biphenols (PCBs) are chemicals that get into our food from the environment. They have no immediate effect on our health but can cause problems if they are absorbed into our bodies at high levels for long periods. Foods high in 4.0 / 5 based on 1 rating
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