RHEOLOGICAL AND PHYSICOCHEMICAL PROPERTIES OF DERIVATIZED WHEY PROTEIN CONCENTRATE POWDERS

Abstract

ABSTRACT The gelling ability of whey proteins provides important textural and water holding properties in many foods. However, because many products cannot be heated to the temperature needed for thermal gelation of whey proteins, cold-set gelation of whey proteins could be very advantageous to the food industry. A derivatization procedure for the production of a cold gelling whey protein isolate (WPI) consisting of protein hydration, pH adjustment, thermal gelation, freeze drying, and milling was applied to three commercial whey protein concentrates (WPC). The resulting derivatized WPC powders were reconstituted in water and evaluated through a range of rheological and physical property studies. The effects of temperature, concentration, and shear on viscosity as well as water holding capacity and intrinsic viscosity were assessed. Although the composition of the starting materials influenced the functionality of the final derivatized powders, all samples exhibited a dramatic increase in thickening and water holding ability. All samples were able to form cold-set weak gel structures suitable for contributing viscosity and texture to a wide range of food systems.