ABSTRACT
This chapter describes the chemical transformations of tryptophan induced by heat, acids, bases, carbonyl compounds, carbohydrates, halogens, lipids, nitrites, oxidizing agents, sulfites, other food ingredients, and some of the resulting nutritional and toxicological consequences. However, new data show that reactions of tryptophan during food processing, especially during thermal treatments, could be of nutritional and toxicological importance. Chemical transformations of tryptophan are essentially a function of the temperature and the duration of treatments. In the presence of hydrochloric acid and oxygen, tryptophan degradation increases with both time of heating and temperature. In the presence of hydrochloric acid and oxygen, tryptophan degradation increases with both time of heating and temperature. Organic acids, such as p-toluenesulfonic acid, mercaptoethanesulfonic acid, and methanesulfonic acid may be suitable for determining tryptophan under acid hydrolysis conditions. The effects of heating time and temperature on racemization of free tryptophan in strongly basic solutions were studied by Spies and Chambers.
