Synergistic modification of ultrasound and bamboo leaf flavonoid on the rheological properties, multi-scale structure, and in vitro digestibility of pea starch

Abstract

In this study, the effect of ultrasonic treatment (UT), bamboo leaf flavonoid (BLF), ultrasonic treatment prior to bamboo leaf flavonoid (UT-BLF), and bamboo leaf flavonoid prior to the ultrasonic treatment (BLF-UT) on the rheological properties, multi-scale structure, and digestibility of pea starch (PS) were investigated. The morphology and crystal structure of starch granules were destroyed by UT, thereby promoting starch retrogradation and digestion. The binding between BLF and starch through hydrophobic interactions and hydrogen bonds inhibited the interaction between starch molecular chains and impaired their double helix structure, thus effectively retarding starch retrogradation. The anti-digestibility of starch was enhanced after synergistic treatment. Compared with single treatment, synergistic treatment increased the ordered structure and gelatinization enthalpy of starch. In comparison with the UT-BLF group, the viscoelastic and thermal stability of BLF-UT group were improved with the increase in ordered structure. This study could provide valuable information for PS modification.

Keywords: Bamboo leaf flavonoid; In vitro digestibility; Interactions; Multi-scale structure; Ultrasound.