Fabrication, modification, interaction mechanisms, and applications of fish gelatin: A comprehensive review

Fish gelatin (FG) is an essential natural biopolymer isolated from aquatic sources and has been considered as a feasible substitute for mammalian gelatins. However, its inferior mechanical and gelling properties limit its applications. Consequently, FG has been modified using various methods. This review summarizes the extraction techniques (including traditional acid and alkaline methods, as well as newer technologies such as ultrasonic-assisted and microwave-assisted extraction), modification strategies (mechanical treatments, physical mixing with polysaccharides, utilization of the Hofmeister effect, chemical modifications, etc.), along with their mechanisms of action. Additionally, we discussed the applications of FG and its modified products. Furthermore, this review highlights the safety and prospects for FG and its derivatives. The mechanical properties and biological functions of FGs are enhanced after modification. Thus, modified FG composites exhibit diverse applications in areas such as foaming agents and emulsifiers, food packaging, three-dimensional printing, drug delivery systems and tissue engineering. This paper aims to provide comprehensive information for future research on FG with the intention of broadening its applicability within the industries of food, cosmetics, and pharmaceuticals. Nevertheless, the development of tough gels, aerogels, and stimuli-responsive hydrogels based on FG requires further investigation.