啤酒花活性成分与抗氧化活性的相关性

以3个品种的萨斯特啤酒花为原料,比较了其石油醚、氯仿、乙酸乙酯、正丁醇和水相等不同极性溶剂提取物中α-酸、β-酸、总黄酮和总多酚的含量,采用·OH、1,1-二苯基-2-三硝基苯肼自由基、β-胡萝卜素-亚油酸3种不同的抗氧化活性评价体系对各极性溶剂提取物的抗氧化活性进行了研究,并与其活性成分的含量进行了相关性分析。结果表明,啤酒花各极性部位均具有不同程度的抗氧化活性。α-酸、β-酸在石油醚相中含量较高,在3个啤酒花样品中的含量范围分别为α-酸444.29～583.81 mg/g、β-酸131.83～293.19 mg/g,在氯仿相中含量相对较低,其余提取物中均未检出;相关性研究表明α-酸、β-酸是石油醚和氯仿相抗氧化活性的主要物质基础。中等极性和极性较大溶剂提取物中啤酒花总黄酮、总多酚含量较高,相关性研究也表明黄酮、多酚类物质是这类提取物抗氧化活性的主要物质基础;其中,3个啤酒花样品中总黄酮、总多酚在乙酸乙酯相中含量最高,分别为20.43～24.13 mg/g和34.97～40.24 mg/g,正丁醇次之,分别为9.45～11.68 mg/g和12.12～19.14 mg/g。

Correlation of Antioxidant Activity with Bioactive Components of Hops

Three varieties of SAST hops were extracted with solvents of different polarities including petroleum ether, chloroform, ethyl acetate, n-butanol and water. The contents of α-acids, β-acids, total flavonoids and total polyphenols in these extracts were measured and compared. Their antioxidant activities were evaluated by hydroxyl radical scavenging, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and β-carotene-linoleic acid model system assays. The correlation was analyzed between the antioxidant activity and the contents of bioactive ingredients. The results showed that all parts of hops displayed antioxidant activity. α-Acids and β-acids were more abundant in the petroleum ether extracts, which ranged between 444.29-583.81 and 131.83-293.19 mg/g, respectively; however, lower values were detected in the chloroform extracts, and undetectable levels were found in other extracts. The correlation analysis suggested that α-acids and β-acids were the main antioxidant compounds in the petroleum ether and chloroform extracts. The medium and highly polar solvent extracts were rich in total flavonoids and total polyphenols, which were the main antioxidant compounds. For all three varieties, the highest contents of total flavonoids (20.43-24.13 mg/g) and total polyphenols (34.97-40.24 mg/g) were in the ethyl acetate extracts followed by the n-butanol extracts (9.45-11.68 and 12.12-19.14 mg/g).