Abstract: Polyphenols, a class of compounds in plant foods, have excellent biological activities, including antioxidant, anti-inflammatory, and antitumor effects. However, polyphenols are susceptible to external adverse factors such as high temperature, light and alkaline conditions during food processing, storage, and digestion, resulting in partial or complete loss of their biological activities. As a natural polysaccharide, gel systems based on starch have good biocompatibility, degradability and safety, as well as excellent encapsulation capacity and effective controlled release effect on active small-molecule compounds due to their unique three-dimensional network structures. Starch-based gels fabricated through different approaches including 3D printing, covalent or non-covalent cross-linking, and gel fillers have a promising prospect in improving the stability and bioavailability of polyphenols. In this article, the biological activities and limitations of polyphenols are described. The relationship between starch properties such as gelatinization, retrogradation and gelling properties as well as different cross-linking strategies and the formation of starch-based gels is discussed. Furthermore, the role of polyphenols in the formation of starch-based gels and how starch-based gels in turn affect the encapsulation and release properties of polyphenols are analyzed. Finally, future applications and challenges of polyphenols encapsulated by starch-based gel systems in the food industry are also discussed.

Key words: polyphenols; biological activity; delivery systems; starch; gels