Analysis of Lactose-Protein Maillard Complexes in Commercial Milk Products by Using Specific Monoclonal Antibodies

Abstract

Lactose-protein Maillard complexes were immunochemically analyzed in various commercial milk products by ELISA and Immunoblotting using a specific monoclonal antibody. The Maillard complexes were detected in all samples analyzed, i.e., modified milk powder, skim milk powder, market pasteurized milk, milk beverages and concentrated milk. The apparent contents of Maillard complexes did not necessarily correlate to the loss of free amino groups, and the contents were generally higher in powdered milk products and milk beverages than in the market pasteurized milk. There appeared to be some relationship between the content of Maillard complexes and the time and temperature for pasteurization. Caseins were the major proteins detected by the antibody as lactose-protein Maillard complexes in various commercial milk products, though several whey proteins and unidentified polymerized proteins were also detected in some of the milk products. Thus, the monoclonal antibody was useful for in situ detection of lactose-protein Maillard adducts in milk and milk products.