Effect of whey protein concentrate addition on the physical properties of homogenized sweetened dairy creams

The influence on their whipping properties of homogenization at first and second stage pressures of 3.5/1.5 MPa and addition of whey protein concentrate (WPC) powder at three different (0.7, 1.4, and 2.1 wt percentage) concentrations to sweetened and homogenized creams was studied. Homogenization of cream significantly decreased maximum overrun and made the foam microstructure less open, while increasing whipping time, cream and foam lightness (Hunter L-value) and apparent viscosity. It also resulted in a less elastic foam structure with an increased drainage. Addition of WPC decreased the amount of maximum overrun, foam drainage and its lightness in parallel with developing a more compact microstructure. It increased the whipping time, apparent viscosity of unwhipped creams and foams, and resulted in a less elastic foam structure. The apparent viscosity of whipped cream with 2.1 wt percentage WPC, however, was lower than that of whipped cream with 1.4 wt percentage WPC, due most probably to the start up of gel formation at 2.1% WPC concentration in sweetened cream when it was sheared. Fresh foam whipped from sweetened cream with 2.1 wt percentage WPC also tended to have a slightly but not statistically significant lower elastic modulus (G') than fresh foam whipped from sweetened cream with 1.4 wt percentage WPC. This concentration can be considered as the critical value for gel formation in sweetened creams enriched by whey proteins when sheared. This study indicated the potential of WPC powder for reducing foam drainage from whipped homogenized sweetened cream.