Engineering Agriophyllum squarrosum starch-butyric acid complexes with functional properties via ionic liquids-ultrasonication synergy.

This study investigates the development of a novel starch-based functional ingredient derived from small-granule Agriophyllum squarrosum starch (ASS), whose molecular chains can form inclusion complexes with butyric acid (BA) via non-covalent interactions. The effects of ionic liquids and ultrasonication pretreatments on the structure and physicochemical properties of regenerated ASS were systematically examined, along with their combined impact on the functionality of ASS-BA complexes. The results indicated that appropriate pretreatment an ionic liquids-water system (8:2, w/w) combined with ultrasonication promoted the formation of hydrophobic cavities within ASS chains, facilitating subsequent complexation with BA. The resulting ASS-BA complexes exhibited a significantly increased resistant starch content, enhanced thermal stability, and improved BA retention during in vitro digestion. Molecular docking and quantum chemical analyses revealed the non-covalent interactions responsible for stabilizing the complexes, while Pearson correlation analysis further linked the structural properties of regenerated ASS to the functional performance of ASS-BA complexes. In a murine colitis model, the ASS-BA complex exhibited superior protective effects than ASS alone, underscoring its potential for mitigating intestinal inflammation. Overall, these findings provide new insights into the formation and functionality of small-granule starch-BA inclusion complexes and highlight their potential as a novel starch-based health food ingredient.