Pullulanase-assisted bamboo leaf flavonoids optimize the instant properties, in vitro digestibility, and underlying mechanism in yam flour

Abstract

In this study, pullulanase-assisted bamboo leaf flavonoids (BLF) were employed to ameliorate limitations of fluidity and digestibility of cooked yam flour via physicochemical properties, digestion, structure and interaction analysis. The results showed that 1) Pullulanase-assisted BLF significantly increased the water solubility (9.02% → 69.38%) and inhibited the swelling (5.54 g/g → 2.29 g/g) during heating and cooling of yam flour, causing it to have liquid-like rheological properties (the tanδ tended to 1). 2) Pullulanase and BLF synergistically affected the anti-digestion of yam flour, reducing the estimated glycemic index to a lower level (58.27 → 48.26, dose-dependent of BLF). 3) Pullulanase-assisted BLF mainly interacted hydrophobic with various components, especially starch, increasing the short/long-range ordered structure of starch, changing the secondary structure of proteins, and forming a tight three-dimensional network structure. This study provided a theoretical foundation for the development of functional foods using yam flour and its potential application in liquid foods.