Fabrication, interaction mechanism, functional properties, and applications of fish gelatin-polysaccharide composites: a review

Fish gelatins (FGs), which have been considered as excellent candidates to substitute mammalian gelatins, are important food hydrocolloids isolated from aquatic resources. However, some undesirable sensory and physicochemical properties limit the applications of FGs. Over the past decade, many studies have reported the modification of FGs using polysaccharides and the FG-polysaccharide composites show great potentiality in food industry. This review summarizes and discusses fabrication methods, interaction mechanism, functional properties, and applications of FG-polysaccharide composites. Various approaches including physical mixing, chemical cross-linking, and enzymatic cross-linking have been put forward to prepare the FG-polysaccharide composites. Therefore, non-covalent and covalent bonds occurred between the two types of macromolecules. Mechanical properties (gel strength and barrier property) and biological functions (mainly antioxidant and antimicrobial activity) of FGs are improved after the addition of polysaccharides. The FG-polysaccharide composites show wide varieties of applications in food packaging, wound dressing, and drug delivery. Further scientific studies such as determining the structural and physicochemical properties of FGs and polysaccharides, optimizing reaction conditions, identifying interaction mechanisms, and expanding their applications in food, cosmetics, and medical industries are urgently required.