Analysis of the Differences in Active Ingredients Content and Antioxidant Activity in Tender Leaves of Vaccinium dunalianum Introduced From Different Regions
The research focused on tender leaves of Vaccinium dunalianum Wight from different regions.The mineral elements in dried tender leaves were analyzed using Inductively Coupled Plasma Atomic Emission Spectrometry(ICP-AES).High-performance liquid chromatography(HPLC)was employed to analyze the major components and their concentrations in the alcohol extract of tender leaves.The total polyphenol in the alcohol extract of tender leaves was determined using the Folin-Ciocalteu method.The antioxidant activity in the alcohol extract of tender leaves in vitro was assessed by the analysis of DPPH·and·ABTS+scavenging capabilities,as well as Fe3+reduction capacity.The correlation between total polyphenol content and antioxidant activity of the alcohol extract of tender leaves was analyzed by Pearson method.The results showed that tender leaves of V.dunalianum from different regions were rich in potassium(K)and calcium(Ca).Although there were variations in mineral elements content,their changing patterns were relatively consistent.The three major phenolic compounds in the alcohol extract were in the order of 6'-O-caffeoyl arbutin>β-arbutin>chlorogenic acid.The total polyphenol content ranged from 42.79 to 53.36 mg/g,with semi-inhibitory mass concentration(IC50)values for DPPH·and·ABTS+clearance ranged from 6.26 to 8.95 mg/L and 8.17 to 14.35 mg/L,respectively,indicating significant reduction capacity.Correlation analysis revealed that there was a significant positive correlation between 6'-O-caffeoyl arbutin,the total polyphenol content,as well as antioxidant activity.Therefore,the content of 6'-O-caffeoyl arbutin,and total polyphenols could serve as important quality indicators for evaluating tender leaves of V.dunalianum as raw materials for Quezui tea.