Structural, Functional, and Technological Perspectives of Whey Proteins: Composition, Chemical Modification, and Industrial Applications

Background: Whey proteins, obtained from the liquid by-product of cheese production, are one of the most valuable sources of bioactive and functional proteins. Thanks to their excellent amino acid profile, high digestibility, and technological versatility, they have been increasingly valued as natural ingredients in food, nutraceuticals, and pharmaceuticals. Their efficient utilization requires a deep understanding of their structural features and functional properties, including the consequences of their processing or chemical modification. Objective: The objective of the present review is to explain the composition, structure, technological functionality, and chemical modifications of whey proteins, in particular β-lactoglobulin and α-lactalbumin, in order to provide a comprehensive understanding of their physicochemical behavior and their industrial applicability. Methods: A literature review was performed based on classical and current sources of Walstra et al., ۲۰۰۵; Kinsella & Whitehead, ۱۹۸۹; Morr & Ha, ۱۹۹۳; Smithers, ۲۰۰۸. Data compiled were synthesized into thematic sections consisting of whey composition, fractionation of proteins, thermal and non-thermal methods of concentration, functional properties comprising solubility, gelation, emulsification, and foaming, and modification techniques including succinylation, phosphorylation, esterification, and enzymatic hydrolysis. The results were interpreted in terms of their physicochemical mechanisms and performance in various food systems. Results: Whey proteins showed excellent solubility, water‑binding, gelling, and emulsifying properties, which, nevertheless, were strongly dependent on pH (optimum ≈ ۶.۵–۷.۰), ionic strength, and heat treatment up to ۵۰–۷۵ °C. Chemical modifications improved dispersion, viscosity and emulsion stability, although some, for example succinylation and acetylation, reduced nutritional quality through lysine inactivation. In an industrial context, whey protein concentrates (۶۰%) texturally mimicked cooked egg whites upon heat treatment, ۸۰–۱۰۰ °C for ۱۰–۳۰ min, and were able to replace up to ۱۰۰ % egg in bakery foams and ۲۰ % flour in cereal systems without negative effects on texture. Applications range from dairy desserts, beverages, and meat products to infant formulas and low‑fat spreads, in which WPC and WPI serve as natural emulsifiers, texturizers, and binders. Conclusion: Whey proteins and their derivatives are multifunctional ingredients combining high nutritional value with desirable techno‑functional properties. Advances in membrane filtration, ion‑exchange fractionation, and environmentally safe modification techniques allow targeted design of protein ingredients with optimized solubility, gelling, and emulsifying capacities. Understanding their molecular stability and interaction with other food components is essential for innovating sustainable protein systems and developing high‑quality functional foods.

کلیدواژه ها:

Whey Protein ، β‑Lactoglobulin ، α‑Lactalbumin ، Functional Properties ، Chemical Modification ، Succinylation ، Emulsification ، Gelation ، Industrial Application ، Dairy Technology