Functionalized milk protein concentrates: reconstitution behavior and their usage in high protein dairy systems

Abstract

High protein ingredients derived from milk are preferred choice in food application due to their nutritional and functional benefits. Complete rehydration of high protein powders is essential before they can be used in any product. Fast and easy method for measuring the rehydration behavior is crucial for the manufacturer and product developers. When casein-based powders are stored for longer time at high temperature the solubility decreases due to formation of the water impermeable layer mostly composed of proteins. By measuring the surface adsorption water by milk protein concentrate (MPC) samples in a saturated chamber predictive models were developed. Gradient Boosting Regressor and Multilayer perceptron models worked best for measurement of solubility and relative dissolution index. Hence, a simple water activity meter can be used to measure rehydration behavior of MPC powders. After rehydration, specific functionalities are essential when incorporating high protein powders into product formulations such as yogurt and beverages. Managing the interaction between the two primary dairy proteins, casein and whey protein, during heat treatment significantly influences the final product's properties. The formation of whey protein aggregates and their reintroduction into a high-protein formulation with casein has shown promising results in enhancing functionalities. Large whey protein aggregates formed at elevated pH levels produced acid gels with the same strength as unmodified whey proteins. Additionally, the ratio of casein to whey protein played a more crucial role in gel formation than the modification of whey proteins. In another work, small aggregates were formed at low pH (~3.5) and under high shear and temperature due to electrostatic repulsion and high surface charge. When the small whey protein aggregates were added in combination with casein in different ratios high protein beverages (8 and 10% protein) it showed high thermal stability during heating at 140°C. Hence, controlling the size of aggregates can improvise the functional properties of whey proteins and help in developing high protein products with desired properties.