葡萄皮渣多酚超声波辅助提取工艺响应面法优化及抗氧化活性研究

摘要

以酿酒葡萄皮渣为原料采用超声辅助法提取葡萄皮渣多酚,在单因素试验基础上固定超声功率100W、乙醇体积分数40%,采用三因素三水平的响应面试验优化设计方法,研究液料比、提取时间和超声温度对多酚得率的影响,依据回归分析得到最佳提取工艺条件为液料比16：1（mL/g）、超声提取时间57min、超声温度50℃。在此条件下葡萄皮渣多酚提取量为（42.51±1.21）mg/5g。以水溶性VE为对照物,通过DPPH法和铁氰化钾法对葡萄皮渣多酚的抗氧化活性进行体外评价,发现葡萄皮渣多酚具有较强的清除DPPH自由基能力和还原能力。由此可以得出,葡萄皮渣多酚具有一定的抗氧化活性,并在一定的范围内,其抗氧化活性与提取液的质量浓度具有较好的线性关系。%Response surface methodology was employed to optimize the ultrasonic-assisted extraction of polyphenols from grape skin as a byproduct of wine making.On the basis of one-factor-at-a-time experiments,through which the optimal ultrasonic power and ethanol concentration were found to be 100 W and 40%,respectively,polyphenol yield was investigated by response surface methodology with respect to liquid-to-material ratio,extraction time and temperature at three levels.The optimal levels of liquid-to-material ratio,extraction time and temperature were determined to be 16：1（mL/g）,57 min and 50 ℃.Under such conditions,the yield of grape skin polyphenols was（42.51 ± 1.21） mg/5 g.The antioxidant activity in vitro of the obtained extract was evaluated by DPPH free radical scavenging assay and potassium ferricyanide reduction assay using water-soluble VE as the control.Grape skin polyphenols were found to have powerful DPPH free radical scavenging capacity and reducing power in a linear dose-dependent manner.