The effect of protein profile and preheating on denaturation of whey proteins and development of viscosity in milk protein beverages during heat treatment

The effect of preheat temperature (63 or 77 degrees C for 30 s; final heat 120 degrees C for 30 s) and casein to whey protein ratio on the physical characteristics of 3.3%, w/w, dairy protein beverages was investigated. Dispersions preheated at 77 degrees C had lower viscosity than dispersions preheated at 63 degrees C. Casein-containing dispersions had significantly lower levels of alpha-lactalbumin denaturation than whey protein-only dispersions. A higher proportion of casein improved the thermal stability of protein dispersions. Overall, alteration of preheat temperature and casein to whey protein ratio can influence dairy beverage quality, with increasing levels of casein reducing physical changes due to heat treatment.