Gelation and Emulsification Properties of Partially Insolubilized Whey Protein Concentrates

Ultrafiltered retentate of whey was heat‐processed to prepare whey protein concentrates (WPC) with protein solubilities ranging from 27.5% to 98.1% in 0.1M NaCl, pH 7.0. Proximate and protein compositions of each WPC were determined. Properties of 20% (w/w) protein WPC gels in 0.1M and 0.6 M NaCl, pH 7.0, on heating to 60, 70, 80, and 90°C and emulsification properties of WPC (0.5% (w/w) protein) in 0.1M NaCl at pH 6.0, 7.0 and 8.0 were analyzed. Gel apparent stress and strain at failure decreased and expressible moisture increased as solubility decreased from 98.1% to 41.0% at all heating temperatures. Emulsification Activity Index was highest at pH 7.0, emulsions were most stable at pH 8.0.