Improvement of heat stability and emulsifying activity of ovalbumin by conjugation with glucuronic acid through the Maillard reaction

Ovalbumin (OVA) was conjugated with glucuronic acid (GlcUA) through the Maillard reaction by incubation at 50 degrees C and 65% relative humidity. Approximately 32 and 45% of the free amino groups of OVA were blocked with GlcUA after 1 and 2 days of incubation respectively, and these values were lower than those with glucose. Polymerization and browning color development of OVA modified with GlcUA were more marked than those with glucose. It was considered that the preferable incubation time was less than I day since the brown color development and polymerization of OVA proceeded quickly during incubation. OVA-GlcUA-conjugates prepared by the incubation for 0.5 or 1 days were soluble after heating the solution at 95 degrees C for 10 min whereas most of the intact OVA was precipitated at 90 degrees C. Emulsifying properties of OVA were improved by conjugation with GlcUA. (C) 1999 Canadian Institute of Food Science and Technology. Published by Elsevier Science Ltd. All rights reserved.