Effects of nonthermal physical processing technologies on functional, structural properties and digestibility of food protein: A review

Abstract This review assesses the nonthermal physical processing technologies for protein modification. The review also discusses the structural, functional, and digestibility attributes of protein following nonthermal physical processing. Applications of ultrasonication, ultrahigh pressure, and pulsed electric field (PEF) can induce the conformational changes of protein via the creation of free radicals and/or larger/smaller protein molecules, damaging the primary, secondary, tertiary, and quaternary structure of protein, and thus influence the functional properties. Some key achievements in using nonthermal physical technologies to process protein‐rich foods include improved enzymatic hydrolysis, solubility, emulsification, foaming, gelatinization, digestion properties, and reduced allergenicity. Therefore, nonthermal physical technologies are useful methods to modify food protein structure and functionality for the food industry. Practical Application The demand for protein with desirable functional properties and nutritional value makes it imperative to find suitable processing technologies that could conserve or yield high quality proteins from both conventional and nonconventional sources. Since thermal processing (including microwave, radiofrequency heating, etc.) could possibly reduce the quality attributes of proteins, many researchers have focused their investigations on nonthermal physical processing to improve the functional properties of proteins. To this regard, this review discusses nonthermal techniques, including ultrasonication, high‐pressure processing, PEFs, cold plasma, and ultraviolet.