Reactions Involved in Food Processing

The nature and extent of the chemical changes induced in proteins by food processing depend on a number of parameters, for example, composition of the food and processing conditions, such as temperature, pH or the presence of oxygen. As a consequence of these reactions, the biological value of proteins may be decreased  

Formation of toxic degradation products is also possible. The nutritional/physiological and toxicological assessment of changes induced by processing of food is a subject of some controversy and opposing opinions. 

The Maillard reaction of the -amino group of lysine prevails in the presence of reducing sugars. 

In the case of cystine, the eliminated thiolcysteine can form a second dehydroalanine residue  

Alternatively, cleavage of the cystine disulfide bond can occur by nucleophilic attack on sulfur, yielding a dehydroalanine residue via thiol and sulfinate intermediates  

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