Research Progress on Preparation and Modification of Sodium Alginate-based Gel Spheres and Its Application in Food Packaging

Sodium alginate is a natural polysaccharide material with good gel properties. Presently, the sodium alginate-based gel beads prepared by gel properties are mainly used as microcapsules in the encapsulation of probiotics, the immobilization of cells and enzymes, and the encapsulation of essential oils. However, in recent years, using sodium alginate gel spheroidization technology to package viscous liquids has also attracted many studies, showing good application prospects. This paper summarizes the formation mechanism of sodium alginate gel balls. The preparation methods and application scope of sodium alginate gel balls were mainly summarized, including the forward spheroidization method, emulsion gel method, reverse spheroidization method, frozen reverse spheroidization method and coaxial extrusion method. Because the gel strength, water holding capacity and embedding rate of sodium alginate-based gel beads greatly affect their application, the compound mixing and hydrophobic modification of sodium alginate and the improvement method of secondary coating of sodium alginate-based gel beads were discussed. Finally, the application and development prospect of sodium alginate gel beads in food packaging was introduced, which provided theoretical references and new ideas for future research on sodium alginate gel beads in food packaging.