Separation of principal component dihydromyricetin from Ampelopsis grossedentata by high-speed counter-current chromatography and its interaction with corn starch.

Ampelopsis grossedentata (AG) is an industrial crop in the grape family, which has been used as a dual-purpose plant for medicine and tea with high medicinal values. However, little is reported on the separation technology of active components from AG and processing technology of AG products. High-speed counter-current chromatography (HSCCC) was applied to separate the principal component dihydromyricetin (DMY) from AG. DMY is added to starch-based products to improve food quality. The interaction between corn starch (CS) and DMY was investigated to predict and control the structure and function of starch-based foods. Results show that DMY with 97.13% purity was successfully obtained by HSCCC using a solvent system composed of light petroleum-ethyl acetate-methanol-water-trichloroacetic acid (1:3:1:3:0.01, v/v/v/v/v). Fourier-transform infrared spectroscopy (FT-IR) exhibits that the interactions between CS and DMY included hydrogen bond and noncovalent bond. X-ray diffraction (XRD) shows that DMY could increase the relative crystallinity of CS. Low-field nuclear magnetic resonance results (LF-NMR) imply that DMY decreased the spin relaxation time (T 2 ) and inhibited the mobility of free water. Atomic force microscopy (AFM) results suggest that DMY changed the surface morphology of CS through hydrogen bond interaction. Moreover, the results of confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) indicate that DMY could enlarge the pores and change the microstructure of CS-DMY complexes. The findings promote the development of industrial CS-based products and utilization of corn crop.