Abstract: An emulsion gel stabilized by a mixture of whey protein and pectin (WP) and an emulsion gel stabilized by a mixture of whey protein and glucan (WG) were prepared by an acid induction method. The functional properties of WP and WG emulsion gels with dispersed phase volume fractions of 35% and 75% (called WP35, WG35, WP75, and WG75) were evaluated and compared, and the efficiency of high internal phase emulsion gels as a fat replacer in replacing fat in low-fat processed cheese was further investigated. The results showed that WP75 had the smallest mean particle size, uniform fat distribution, and a stable protein network structure. Within the frequency range of 0.1–10 Hz, both the elastic modulus (G’) and viscous modulus (G”) values of the emulsion gel samples tended to increase as the oil phase volume fraction increased. Compared with the other samples, WP75 was superior in terms of deformation resistance, thermal stability, and water-holding capacity. Addition of WP75 into processed cheese with 15% (m/m) fat reduced the oil syneresis and increased the meltability without resulting in significant differences in textural properties compared with the control group (full-fat). This study demonstrated that high internal phase emulsion gels stabilized by whey protein and pectin could be used as a fat replacer in the development of low-fat cheese products.

Key words: whey protein; pectin; glucan; high internal phase emulsion gel; low-fat processed cheese