kindly inform ..
sucrose reaction with sodium bezoate cause blacknig why
and sucrose are also break by citric acid,,,,,why
1/5/18
Dear Arsalan,
Sucrose is an oligosaccharide (specifically, a disaccharide). These are subject to hydrolysis in the presence of acid and heat. Some oligosaccharides are very difficult to hydrolyze, while others are very acid labile (i.e., hydrolyze very easily). This is due to their specific make-up (i.e., sugar building blocks) and the type of glycosidic linkage. Unfortunately, sucrose is one of the more easily acid-hydrolysable sugars. Even a relatively weak acid such as citric acid will do it. This is probably what happened to your sucrose.
In water, sodium benzoate will have a pH of ~8. The reaction mechanism by which sucrose undergoes "acid" hydrolysis can occur at a pH as high as ~8.3. It's possible the NaBenzoate is also causing some sucrose to hydrolyze. I can't explain the formation of the black color.
I hope this helps you.
Bill Colonna Center for Crops Utilization Research, Iowa State University, Ames, IA USA [email protected]
I have some papers and a thesis related to starch cross-linking and hydrolysis by with citric acid. Simple pH adjustment reduces the hydrolysis significantly if that is something you wish to avoid. Also, the mixing order related to temperature treatments can be of interest to keep track on.
BR
Erik
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