Effect of Maillard reaction conditions on the gelation and thermal stability of whey protein isolate/d-tagatose conjugates

Abstract

The Maillard reaction (MR) was used as a natural modification method to improve the functionality of proteins by covalent interaction with monosaccharides. This study aimed to prepare whey protein isolate (WPI)/d-Tagatose (DT) conjugates by dry heating treatment to investigate the effect of different MR conditions on the structural changes of WPI and its effect on the WPI/DT conjugates gelation and thermal stability. Covalent interactions between WPI and DT were detected using multi-spectral methods. The MR conditions significantly affected the degree of glycosylation, structure, and molecular weight of the WPI/DT conjugates (P < 0.05). The MR changed the WPI/DT conjugates gel properties and thermal stability, where the WPI/DT 1:1–1 gel properties were stronger than those of WPI-1 and the heating deflection temperature after glycosylation was increased to 163.55 °C (P < 0.05). This study provides a theoretical basis for the application of DT as food ingredient in the development of WPI functional properties by MR.