Characterization and adsorption-release property of fermented porous starch as well as its bioactivity protection for guava leaf polyphenols

Abstract

Porous starch has been considered an effective delivery system for bioactive substances such as polyphenols. However, conventional preparation methods of porous starch are complex, costly and easily cause pollution, which limits large-scale production. To explore a better method for the clean production of porous starch, this study prepared porous starch by fermentation with Monascus anka GIM 3.592 and constructed a delivery system of guava leaf polyphenols based on fermented porous starch (FPS). The results show that the surface of FPS was porous, and the specific surface area of FPS was nearly twice that of native starch. The adsorption capacity of fermented starch was increased by 217.18% compared with native starch and slightly higher than that of commercial porous starch. The FT-IR intensity ratio of the 995/1022 and 1047/1022 bands and relative crystallinity increased, while the particle size of fermented starch decreased. The adsorption depended on hydrogen bonds, and the adsorption of fermented starch to quercetin was stronger than that of other flavonoid glycosides from guava leaf polyphenols, where the adsorption rate reached 63.74% ± 0.28%. Furthermore, antioxidant activity protection and sustained release of the polyphenol-starch complex were achieved. This study provides a promising strategy to prepare porous starch and construct a polyphenol delivery system.