Emulsification and encapsulation properties of conjugates formed between whey protein isolate and carboxymethyl cellulose under acidic conditions

Abstract

In this study, carboxymethyl cellulose (CMC) was used to interact with whey protein isolate (WPI) to prepare conjugates as emulsifiers and embedding agents, which can be used under acidic conditions. Firstly, the effects of ratios and pH values on the formation of WPI-CMC conjugates were investigated. The turbidity and particle size of WPI were reduced in the presence of CMC at pH 4.6 (near the isoelectric point). Then the characterization of physicochemical properties indicated that electrostatic interactions played a major role in the formation of WPI-CMC conjugates, thereby changing the structure and function of conjugates. CMC and WPI reached the optimal aggregation state at pH 4.6 and a ratio of 4:1. The conjugates exhibited excellent emulsifying activity and stability for the oil-in-water emulsions. WPI-CMC conjugates also could provide protection to allicin by preventing degradation under environmental stresses, while maintaining its antioxidant activity.