Enzymatic crosslinking of proteins in the manufacture of fermented milk

摘要

The enzyme transglutaminase (EC 2.3.2.13) catalyses an acyl group transfer between gamma-carboxyamide groups of peptide-bound glutaminyl residues and the primary amino groups in a variety of amine compounds, including peptide-bound e-amino groups oflysyl residues. As a result of intermolecular cross-linking, milk protein polymers with maximum sizes of 10~6 to 10~7 g X mol~(-1) are obtained, but only 1-2 percent of the lysine in milk proteins is bound in iso-peptide cross-links. In the absence of amine substrates, transglutaminase is capable of catalysing the deamidation of glutamine residues. Cross-linking of food proteins by transglutaminase was performed for modifying technofunctional properties like solubility, hydration ability, rheological and emulsifying properties as well as heat stability in model systems.