CHARACTERIZATION, STABILITY AND ANTIOXIDANT ACTIVITY OF THE INCLUSION COMPLEX OF DIHYDROMYRICETIN WITH HYDROXYPROPYL-β-CYCLODEXTRIN

ABSTRACT Dihydromyricetin was a nutraceutical with good prospect in food industry. But its poor water solubility limits its application in hydrophilic food. In this study, by forming the inclusion complex with hydroxypropyl-β-cyclodextrin, the solubility of dihydromyricetin in water increased from 0.74 to 53.64 mg/mL. The physicochemical properties of the complex were analyzed by ultraviolet-visible spectrometry, infrared spectrometry and X-ray diffractometry. The result showed that dihydromyricetin in the complex had been completely dispersed in the hydroxypropyl-β-cyclodextrin matrix, not forming a new compound. The thermogravimetric analysis showed the thermal decomposition of dihydromyricetin could be delayed by forming the inclusion complex. And the stability of dihydromyricetin in water against heat was greatly enhanced. It was found that the complex was an effective scavenger of 1,1-diphenyl-2-picrylhydrazyl radicals with the IC50 value of 39.24 µg/mL, and a linear correlation between concentration of the complex and reducing power was observed with a coefficient of r2 = 0.9834. PRACTICAL APPLICATION Dihydromyricetin was a nutraceutical with good prospect in food industry. But the poor solubility and stability of dihydromyricetin in water restricted its application as an antioxidant and functional supplement in hydrophilic food. In this study, by forming the inclusion complex with hydroxypropyl-β-cyclodextrin (HP-β-CD), the solubility and stability of dihydromyricetin in water was significantly improved. In view of the safety of dihydromyricetin and HP-β-CD, the safety of the complex can be accepted. The obtained complex could be used to develop new functional food.