Influence of whey protein concentrate on the functionality of egg white and bovine serum albumin

Abstract

The objective was to elucidate the functionality of various combinations of egg white (EW), whey protein concentrate (WPC) and bovine serum albumin (BSA) and compare the microstructures of their gels. Dispersions of individual proteins (1%, w/v, in imidazole‐HCl pH 7.0) were prepared. The BSA, EW and WPC and were combined in the ratios of 0 : 0 : 1, 1 : 0 : 0, 0 : 1 : 0, 0.5 : 0 : 0.5, 0 : 0.5 : 0.5, 0.5 : 0.5 : 0, 0.33 : 0.33 : 0.33, 0.42 : 0.16 : 0.42, 0.16 : 0.42 : 0.42 and 0.42 : 0.42 : 0.16. The functionalities studied were oil holding capacity (OHC), water holding capacity (WHC), thermostability (TS), foam activity (FA), foam stability (FS), foam density (FD), emulsion stability (ES) and emulsifying activity index (EAI). Gels with a protein concentration of 10% (w/v) in 0.1 M NaCl at pH 7 were used for determination of stress, strain values and microstructural analyses. The R2 was in excess of 0.95 for all attributes studied except FD which had an R2 of 0.85. The results indicate that WPC apparently impacted water entrapment in an additive manner proportional to its concentration. The combination of WPC with EW or BSA resulted in a synergistic effect for TS and FS and an additive effect for OHC, WHC, FD, EAI, gel stress and strain. On the contrary, an antagonistic effect was observed for FA. If a multifunctional combination was to be picked, it would be a 1 : 1 ratio of WPC and BSA as it had the highest number of attributes with synergistic effects. Data indicated there were multifunctional advantage of using WPC.