Differences in Chemical Changes
Chemical changes occurs in some of the stages in baking.
The first stage is Creaming.
Here, the butter and sugar is being beaten by a wooden spoon. This is to break the molecular bonds between the two compounds and formed links between them. This will help formed the creamy desired mixture.
This occurs in both variations.
The second stage is Addition of the Flour and eggs.
At this stage, there is a difference in both variations due to the different proportions of wheat proteins (gliadins and glutenins) in the flo
urs.
Eggs white contains six types of proteins.
During whipping, two proteins, ovomucin and ovoglobulin will denature and form bonds with other proteins such as wheat proteins and also among themselves.
This is done through the unfolding of the proteins to spread out in the liquid part of the mixture.
Chemical changes occurs in some of the stages in baking.
The first stage is Creaming.
Here, the butter and sugar is being beaten by a wooden spoon. This is to break the molecular bonds between the two compounds and formed links between them. This will help formed the creamy desired mixture.
This occurs in both variations.
The second stage is Addition of the Flour and eggs.
At this stage, there is a difference in both variations due to the different proportions of wheat proteins (gliadins and glutenins) in the flo
urs.Eggs white contains six types of proteins.
During whipping, two proteins, ovomucin and ovoglobulin will denature and form bonds with other proteins such as wheat proteins and also among themselves.
This is done through the unfolding of the proteins to spread out in the liquid part of the mixture.
Two other proteins, ovalbumin and conalbumin will be distributed also at the liquid part of the mixture.
The third stage is BAKING.
The third stage is BAKING.
At this stage, a permanent solid mixture will start to form .
This is as the ovalbumin and conalbumin that was distributed earlier on, will start to denatured annd form bonds with other egg proteins.
Due to the fat in the egg and sugar which inhibits excess gluten network from forming during baking, both variations will be achieved a very tender mouthfeel
However, due to the higher amount of glutenins and gliadins in wholemeal flour, the wholemeal variation will tend to be harder due to more gluten network formed.
The plain flour variation will seem softer in comparison.
Maillard browning reaction will also start to occur here as proteins from the eggs and sugar are heated at a high temperature in the oven.
This is a non-enzymatic browning reaction. This reaction occurs in three stages :
Condensation: Reducing sugar and amine sources from protein condenses into a compound called glycosylamine
Rearrangement: Glycosylamines will now rearrange itself into colourless intermediates.
Polymerization: These colourless intermediates will then polymerize into a brown-coloured polymers called melanoidins.
As the wholemeal flour consists of higher amount of protein than the plain flour, maillard browning reaction is faster.
It will change from colourless to golden to reddish brown and to dark brown.
The plain flour will achieve a golden brown colour due to its lower amount of protein and thus, a slower rate of maillard reaction.
Resources:
This is a non-enzymatic browning reaction. This reaction occurs in three stages :
Condensation: Reducing sugar and amine sources from protein condenses into a compound called glycosylamine
Rearrangement: Glycos
ylamines will now rearrange itself into colourless intermediates.Polymerization: These colourless intermediates will then polymerize into a brown-coloured polymers called melanoidins.
As the wholemeal flour consists of higher amount of protein than the plain flour, maillard browning reaction is faster.
It will change from colourless to golden to reddish brown and to dark brown.
The plain flour will achieve a golden brown colour due to its lower amount of protein and thus, a slower rate of maillard reaction.
Resources:
website: www.nutritionandeggs.co.uk/eggs_nutrition/nutrition1
Books:
Foods: Experimental Perspectives,6th Ed by McWilliams,M
Understanding Food: Principles and Preparation by Amy Brown
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