Ingredients and pH are Key to Clear Beverages that Contain Whey Protein

A challenge of shelf stable beverages that contain whey protein is that a small portion of protein can be denatured and aggregated during thermal processing, resulting in a turbid solution or white precipitate that consumers perceive a defect. In this study, 3 approaches were taken to reduce turbidity In heat-treated beverages that contain whey protein: (1) centrifugation to remove insoluble-protein aggregates, (2) addition of ingredients, and (3) alteration of pH in the range from 3.0 to 4.0. At pH 3.6 and below, all samples were essentially clear both before and after heating for all ingredients. At a pH of 3.8 and above, ingredient selection was crucial to solution clarity after heat treatment. At a pH of 4.0, addition of salsts at both 10 and 50mM increased the turbidity significantly compared to the control, which contained only whey protein in water. Neither addition of sugars at 25, 50, and 100 g/L, nor addition of sugar alcholos at 25 g/L significanlty affected turbidity after heat treatment compared to the control. However, sugar alcholos added at 50 or 100 g/L significantly reduced turbidity after heat treatment compared to the control. Remove of insoluble protein aggregates by centrifugation prior to heat treatment resulted in a statisassist food scientists in selecting processing treatments, ingredients, and pH in the development of shelf stable clear beverages that contain whey protein.