The Physical And Chemical Properties Of Inclusion Complex Of Dihydromyricetin With Hydroxypropyl-β-Cyclodextrin And The Effect Of Interaction Between The Complex And SPI On The Protein Functionality

Leaves of Ampelopsis grossedentata have been consumed in southern China as health teaand herbal medicine. In this study, flavonoid-rich extracts from leaves of Ampelopsisgrossedentata were prepared by traditional solvent extraction and recrystallization. Byanalysis of UV, IR, ESI-MS, NMR, the major flavonoid the products was identified as(+)-dihydromyricetin (DMY).Dihydromyricetin was a natural antioxidant with good prospect in food and medicineindustry. But its poor water solubility limits its application in hydrophilic food. In this study,the inclusion complex of dihydromyricetin with hydroxypropyl-β-cyclodextrin (HP-β-CD)was prepared to improve the hydrophilicity of dihydromyricetin. The physicochemicalproperties of the complex were analyzed by ultraviolet-visible spectrometry (UV), infraredspectrometry (IR), X-ray diffractometry (XRD). The result showed that dihydromyricetin inthe inclusion complex had been molecularly dispersed in the HP-β-CD matrix, not forminga new compound and HPLC analysis showed that the solubility of dihydromyricetin inwater was enhanced from0.74mg/mL to53.64mg/mL. The Stability of the complex wasstudied by Thermogravimetric Analysis (TG) and Stability Test. It could be concluded thatthe decomposition of DMY could be delayed by forming the inclusion complex withHP-β-CD and the thermal stability of DMY in water was greatly enhanced.The antioxidant activity of the inclusion complex was investigated in this study. It wasfound that the inclusion complex was an effective scavenger of DPPH radicals with the IC50value of39.24μg/mL. A linear correlation between concentration of the complex andreducing power was observed with a coefficient of r2=0.9834. In the Rancimat antioxidanttest using lard oil as substrate, the performance of the complex with protection factor of2.21was inferior to that of butylated hydroxytoluene (TBHQ) with protection factor of4.44.In order to determine the anticancer activity of the complex, the anti-proliferativeeffect of the complex and its apoptotic induction in human Hep G2cells was investigated.The result suggested that the inclusion complex of dihydromyricetin withhydroxypropyl-β-cyclodextrin could induce cells into an apoptotic pathway resulting in theinhibition of proliferation of Hep G2.DMY and the inclusion complex have significant effect on the emulsion stability of SPI.The supplementing of DMY and inclusion complex raised gel strength of SPI by23.8%and 47.3%respectively. The preparation of inclusion complex of DMY with HP-β-CD reducedthe effects of DMY on SPI solubility.