High-Pressure–High-Temperature Processing Reduces Maillard Reaction and Viscosity in Whey Protein–Sugar Solutions

The aim of the study was to determine the influence of pressure in high-pressure–high-temperature (HPHT) processing on Maillard reactions and protein aggregation of whey protein–sugar solutions. Solutions of whey protein isolate containing either glucose or trehalose at pH 6, 7, and 9 were treated by HPHT processing or conventional high-temperature (HT) treatments. Browning was reduced, and early and advanced Maillard reactions were retarded under HPHT processing at all pH values compared to HT treatment. HPHT induced a larger pH drop than HT treatments, especially at pH 9, which was not associated with Maillard reactions. After HPHT processing at pH 7, protein aggregation and viscosity of whey protein isolate–glucose/trehalose solutions remained unchanged. It was concluded that HPHT processing can potentially improve the quality of protein–sugar-containing foods, for which browning and high viscosities are undesired, such as high-protein beverages.