Effect of heat treatment on physical properties of whey protein beverages (WPB)

There is a great interest in the production of heat-stable and clear beverages containing high levels of whey proteins. A challenge of incorporating whey proteins in sports beverages is hot-fill treatment (88 °C, 2 min). The objective of this research was to analyze the effects of thermal treatment on the profile of whey proteins in a whey protein beverage (WPB). WPB were prepared mixing 5 % whey protein with 0.04 % potassium sorbate and 0.5 M phosphoric acid was used to adjust pH to 3.0 and 7.0. The protein particle size and zeta-potential were tested using a spectrophotometer. Finally, the protein profile of beverages containing whey was determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Hot-fill treatment had a negative impact on the physiochemical properties of whey proteins. The formation of protein-protein complexes produced an increase in particle size and absolute zeta potential in WPB formulations at both pH 3.0 and 7.0. © 2019 ALMA MATER Publishing House, VASILE ALECSANDRI University of Bacău. All rights reserved.