I hear varying stories here and there about heating proteins from whey protein isolate.
I read that the product I use is made via “ice cold” Cross Flow Ultra Filtration with the aim of retaining as much biological active substances as possible. Heating would cause denaturation of the proteins.
Is it true that heating egg whites is not good? And what does this denaturation mean in concrete terms: does it reduce the biological value (quality) of the proteins used?
(I myself sometimes use whey in cakes and pancakes and was actually wondering if this is a good idea.)
Answer
Hi Thomas,
Proteins are chains of amino acids. In normal (biologically active) state, these chains are partially folded and coiled. These segments further fold together to form a higher-order tangle. Sometimes different protein chains clump together and form a complex in this way.
This structure is essential for the biological functioning of proteins. This ensures that amino acids that are far from one or even on other chains in the linear protein chain come together and form ‘active’ centers.
This structure is lost when heated. The proteins denature. The amino acids of the active centers no longer sit together. When heated, the activity of the protein also disappears.
This makes no difference to the diet. Proteins are denatured in the stomach during digestion (not by heat, but by acid) and are cut into small pieces before being absorbed into the body.
Answered by
Bart De Mey
Kapeldreef 75 3001 Leuven
http://www.imec-int.com
.