Characteristics and antioxidant activities of ovalbumin glycated with different saccharides under heat moisture treatment

Ovalbumin (OVA) was glycosylated with glucose, lactose, maltose and soluble starch respectively under heat moisture treatment at 120 degrees C for 20 min. The UV-vis absorbance and browning intensity, free amino group, thermal properties, tertiary structure and antioxidant activities were investigated. The results indicated that the OVA-glucose and OVA-maltose mixture exhibited stronger browning intensity as well as reducing power and DPPH scavenging activity than other samples. The OVA-lactose and OVA-glucose displayed higher TEAC value, up to 1.92+/-0.11 and 1.96+/-0.14 mmol Trolox/g, respectively. The Maillard reaction involving the condensation of reducing sugar and protein modified the thermal stability of ovalbumin. The tertiary structure of OVA was significantly influenced by the Maillard reaction. The antioxidant activity of the Maillard reaction products prepared in such a short time was so strong, suggesting that generation of in vitro liquid Maillard products is a potential source of external antioxidants for food preservation. (C) 2012 Elsevier Ltd. All rights reserved.