Techniques to improve the functional properties of whey proteins

Whey protein (WP) is a high-quality protein found in milk with a high nutritional value and also distinct physiological functions. Whey protein in its natural state is extremely unstable and hence, many modification techniques have been designed to enhance WP stability for diverse food applications, each with a unique set of characteristics. This paper reviews physical, enzymatic, and chemical methods for modifying whey protein, as well as innovative strategies. The traditional physical methods include thermal processing, texturization, freeze modification, high moisture extrusion, while the enzymatic procedures primarily consist of enzymatic hydrolysis and enzymatic cross-linking, and the ternary system is one of the most commonly adopted chemical processes. Among the novel processing techniques, those most commonly experimented include, high pressure shearing, ultrasound treatment, high hydrostatic pressure, pulsed electric field, and cold plasma technology. This article summarizes the mechanisms of various modification methods of WP structure, texture and other functional properties and their effects on whey protein characteristics, as well as future prospects of development of whey protein modification techniques and its food applications.