Controlled and tailored denaturation and aggregation of whey proteins

Tatiana Vieira

Key information

Authors:

Tatiana Vieira (Tatiana Vieira Arriaga)

Supervisors:

Thom Huppertz (Thom Huppertz); Marília Clemente Velez Mateus (Marília Clemente Velez Mateus)

Published in

November 10, 2011

Abstract

Whey protein denaturation and aggregation is a relevant event in processes in the dairy industry, in controlling the textural properties of a product (e.g., yoghurt), process control and optimization (e.g., fouling of heat exchangers) and in the preparation of milk protein ingredients (e.g., microparticulated whey proteins). In addition, whey proteins are added into a wide variety of non-dairy food products submitted to heat (e.g., caramels and clinical foods) and high pressure treatments. In the presence of high carbohydrate concentration, whey proteins are within a complex system wherefore predicting thermal denaturation and aggregation behavior cannot simply be extracted from comparable effects occurring in milk or whey. To provide reliable information, the influence of carbohydrates on the denaturation and aggregation of whey proteins was assessed in this work. The thermal behavior of whey proteins in the presence of carbohydrates strongly deviates from that under normal conditions whey. The same was not true for high-pressure treatment, less effective in denaturing whey proteins. Both concentration and type of carbohydrate can be used to tailor the heat-induced aggregation of whey proteins and thus allow the development of particles of tailored size and properties. The influence of potassium iodate, a sulphydryl-oxidizing agent, and calcium chloride on the thermal denaturation of whey proteins was tested with the same purpose. Potassium iodate showed no significant influence on the denaturation of the whey proteins. The presence of CaCl2 led to gel formation upon heat treatment, which hardness was dependent on the CaCl2 concentration and the solution pH.