Abstract: The heteroaggregation and transglutaminase-induced aggregation of whey protein isolate (WPI) and lactoferrin (LF) emulsions were investigated in order to improve the rheological properties of the system. WPI and LF emulsions were prepared by microfluidization and the heteroaggregation of emulsion droplets occurred when they were mixed together. After addition of transglutaminase, aggregates were formed by cross-linking, which led to a specific three-dimensional network structure. The mixed 50% LF-50% WPI emulsions showed the greatest degree of aggregation and highest physical stability. Compared with the single WPI and LF emulsions, heteroaggregation enhanced the rheological properties of 50% LF-50% WPI aggregates to 3.72 and 2.2 times, respectively. Notably, the viscosity was increased to 11.4 times through transglutaminase cross-linking. Therefore, it was of great value to improve the rheological properties of food systems by combing heteroaggregation and enzymatic cross-linking. The results of this study will lay a theoretical foundation for developing food lipid substitutes.

Key words: emulsions, heteroaggregation, whey protein isolate (WPI), lactoferrin (LF), transglutaminase, rheological properties