Abstract: Gelatin and polysaccharide gel are two kinds of macromolecular hydrophilic colloids that are widely used in the food industry. But gelatin colloids have insufficient gel network stability and poor thermal stability, and their application is restricted by religious factors. Polysaccharide gels are characterized by insufficient mechanical strength and poor water vapor barrier properties. Gelatin and polysaccharide can interact with each other non-covalently or covalently, resulting in surface selective patch bonding, emptying effect, co-gelation and other phenomena and consequently changing gel properties. By adjusting the pH, mixing ratio, temperature and other conditions that affect the structural formation and improve the gel properties of composite gels, different types of composite gel systems with unique properties can be obtained and used to further prepare nano/micro particles, hydrogels, films, lotions and foams. In this article, the existing problems on polysaccharide and gelatin gelation, the interaction mechanism between them and consequent changes in gel properties, and the external conditions that regulate composite gel properties are reviewed, aiming to provide a theoretical basis for wider application of polysaccharide-gelatin composite gels in the food industry.

Key words: polysaccharide, gelatin, colloids, gel properties, interaction