Study on process of Yak and Holstein casein–glucose Maillard reaction and functional properties of their products

Abstract

Process of Maillard reaction within 180 min was studied using Yak and Holstein casein–glucose models by indicators of free amino group consumption, content of H+, amount of intermediate products and browning intensity, while their kinetics were investigated. Intrinsic fluorescence property of casein during Maillard reaction was also measured. Structure and functional properties of Yak and Holstein casein–glucose Maillard reaction products were evaluated. The results showed similar profiles of free amino group consumption and H+ content against duration in both systems. Higher intensities of intermediate products and melanoidins were found in Yak casein–glucose system compared to Holstein casein–glucose system, as well as rate constant of browning accumulation. The kinetics of free amino group consumption and melanoidins formation for Yak casein were different from those of Holstein casein. Glycosylation improved emulsification, foaming, and oil combining capacity of both caseins, which is reached the best value at the ratio of 2:1 (glucose:casein, wt/wt). Novelty impact statement The Maillard reaction process of Yak and Holstein casein–glucose models were investigated by different indicators, as well as their kinetics. Yak casein–glucose model has similar profile of free amino group consumption and pH change to those of Holstein casein, but higher accumulation of intermediate products and browning intensity. Both Yak and Holstein glycosylated caseins have the best functional properties of emulsifying and foaming activities, emulsion and foam stabilities, and the oil absorption with the weight ratio of glucose:casein at 2:1.