Protein Hydrogels: A Concise Review of Properties and Applications

Proteins are renewable resources generated from residues and byproducts of the agriculture and livestock industries. Numerous in-depth studies have been conducted on proteins for their utilisation as protein-based hydrogels. Henceforth, for maximum enrichment of these dietary proteins in the diet, available proteins are transformed into hydrogels using enzymes, chemicals, or physical means. In addition to being nontoxic, biocompatible, biodegradable, accessible, and renewable, protein hydrogels are also affordable. They come in a wide range of physicochemical states dissolved in emulsions or liquids, like particle hydrogels, macro hydrogels, a form of gel colloid, and suspensions. However, composite or hybrid hydrogels are developed by mixing proteins with polysaccharides and other biomolecules to enhance mechanical and functional properties for specific applications. Additionally, these biomaterials have attracted increasing interest in the past few years owing to their improved tensile strengths and can enclose preserved and released biomolecules. Thus, hydrogels can manage the release of bioactive substances and boost the bioavailability of such ingredients, in addition to their capacity to heal wounds and their use in the food and agriculture industries. This article thoroughly analyses basic polymer hydrogel categorization, diverse protein hydrogel forms, production techniques, physicochemical and functional properties, and applications in various fields. This review also sheds light on methods for determining the shape, thermal stability, and rheological characteristics of protein-based hydrogels. Therefore, will provide a comprehensive reference for the numerous aspects of protein hydrogels that are important to multiple academic and industrial disciplines.