Comparisons of characteristics, kinetics and biological activities of glycosylated α-lactalbumin produced by microwave and conventional heating

Abstract

The characteristics, kinetic mechanisms and biological activities of glycosylated α-lactalbumin prepared under microwave heating (MH) and conventional heating (CH) at 85 °C for 1–3 h were compared and investigated. Glycosylated α-lactalbumin prepared by microwave heating showed a higher degree of browning and more free amino groups as compared to preparation by conventional heating. Studies of the reaction kinetics demonstrated that microwave heating induced a higher rate constant at 75 °C, 85 °C and 95 °C. Similarly, the activation energy of the microwave-mediated process was 8.27 kJ/mol lower than under conventional heating, indicating that microwave heating accelerated the glycosylation of α-lactalbumin. The glycosylated α-lactalbumin produced in the microwave showed greater surface hydrophobicity after 3 h than the conventionally heated product. Glycosylated α-lactalbumin produced via microwave heating also showed higher total antioxidant capacity and α-glucosidase inhibitory activity. Therefore, microwave heating effectively promotes α-lactalbumin glycosylation and enhances the functional properties and biological activities of glycosylated α-lactalbumin.