Effect of egg yolk substitution by sweet whey protein concentrate (WPC) on physical properties of gelato ice cream

The aim of this research was to evaluate the changes in the gelato ice cream properties at different levels of sweet whey protein concentrate (WPC) substitutions of egg yolk. Samples were made with two levels of egg yolk (4.5 and 9%). For each level one control sample with no WPC addition and four levels of WPC substitutions (20, 50, 80 and 100%) were made. Three replications of each treatment were performed. Samples were evaluated for mix viscosity, overrun and texture. Determinations of these parameters were made after four weeks of storage. Results showed that samples containing 9% egg yolk were more viscous than those containing 4.5% egg yolk. Moreover, increasing WPC substitution led to increased overrun (%), number of air cells formation and texture characteristics of the gelato samples. Overall, a significant (P<0.05) effect of fat content was observed and reported in all physical properties measured.