Sweet Whey Protein Isolate to Substitute for Egg Yolk in Gelato
December 1/Ourimbah, Australia/Agriculture Week -- "The aim of this study was to evaluate the changes in Gelato vanilla ice cream physical properties such as viscosity, overrun and texture using different levels of sweet whey protein isolate (WPI) as substitutions for egg yolk. Gelato samples were made with two levels of egg yolk (4.5 and 9%)," investigators in Australia report.
"For each level, one control sample with no WPI addition and four levels of WPI substitutions (20, 50, 80 and 100%) was made. Three replications of each treatment were performed. Viscosity of the mixes was measured while Gelato ice creams were evaluated for overrun and texture (using Cone Penetrometer and Texture Analyser). Determinations of these parameters were made after four weeks of storage. The viscosity scores of the Gelato ice cream were influenced by fat content. Samples containing 9% egg yolk were more viscose than those containing 4.5%. Moreover, there was a significant increase (P<0.05) in overrun (%) by increasing WPI levels in both 4.5% and 9% egg yolk samples. However, higher overruns reduced ice crystal number, whereas lower overruns had no impact on size distributions," wrote M.S. Alfaifi and colleagues, University of Newcastle.