不同提取条件对草莓果实抗氧化物质和抗氧化活性的影响

Effect of Extraction Conditions on Antioxidant Components and Antioxidant Activity of Strawberry Fruit Extracts

以草莓栽培品种"丰香"(Fragaria ananassa Toyonaka,)绿熟阶段的果实为试材,研究提取试剂、温度、时间对草莓果实抗氧化物质和抗氧化活性的影响。结果表明,甲醇-水-盐酸(体积比80:19.9:0.1)提取物中总酚、类黄酮、抗坏血酸,DPPH自由基清除能力和铁还原氧化能力显著高于甲醇、乙醇、甲醇-乙醇-丙酮体积比(1:1:1)和水的提取物。然而,抗氧化物质提取的最佳条件(60℃,480min)与获得最高抗氧化活性的提取条件(25℃,120min)并不一致,说明抗氧化物质含量的高低并不总是草莓果实提取物抗氧化活性强弱的指示剂。综合抗氧化物质的提取量以及提取物的抗氧化活性,甲醇-水-盐酸(体积比80:19.9:0.1)在25℃进行120min草莓果实抗氧化物质的提取更为适合。

Strawberry fruits from Fragaria ananassa ＇Toyonaka＇ picked at the green maturity stage were extracted with different solvents under varying conditions of temperature and extraction time and the extracts obtained were tested for their antioxidant components and antioxidant activity. The results showed that methanol-water-HCl （80：19.9：0.1, V/V） extract revealed a significant increase in the contents of total phenols, flavonoids and ascorbic acid, DPPH free radical scavenging activity and ferric ions reducing power when compared with methanol, ethanol, methanol： ethanol-acetone （1：1：1, WV） and water extracts. The optimal extraction conditions （at 60 ~C for 480 rain） for achieving maximum extraction of antioxidant components did not accord with those （at 25 ~C for 120 min） resulting in maximum antioxidant activity, indicating that the contents of antioxidant components did not necessarily represent the antioxidant activity of strawberry fruit extracts. Comprehensively considering the contents of antioxidant components and antioxidant activity of strawberry fruit extracts, we concluded that extraction with methanol-water- HCl mixture （80：19.9：0.1, V/V） for 120 rain at 25 ℃is more suitable for extracting antioxidant components from Strawberry fruits.