鸡桑叶多酚提取工艺优化及其抗氧化性能

旨在优化鸡桑叶多酚的提取工艺,并考察鸡桑叶多酚的抗氧化性能。以鸡桑叶为原料,多酚提取量为响应值,考察了乙醇浓度、提取时间、液料比和提取温度对鸡桑叶多酚提取量的影响,并进行响应面实验设计与优化。采用自由基的清除法评价鸡桑叶多酚的抗氧化性能。最佳提取工艺条件为:乙醇浓度72%、提取时间116 min、液料比37:1 mL/g、提取温度76℃,鸡桑叶多酚提取量为87.63 mg/g,与模型预测值(87.97 mg/g)相比,其相对误差为0.39%。鸡桑叶多酚对DPPH自由基、羟基自由基和超氧阴离子自由基均具有一定的清除能力,具有明显的量效关系,其IC₅₀分别为54.68、207.16、416.05 mg/L,其效果均小于V_C。所建立的鸡桑叶多酚提取四元二次回归模型有效且准确性较高,得到的鸡桑叶多酚具有一定的抗氧化能力。

Optimization of Extraction Technology of Polyphenols from Morus australis Leaves and Its Antioxidant Activity

The study was aimed to optimize the extraction technology of polyphenols from Morus australis leaves and investigate its antioxidant activity. The effecting factors involving ethanol concentration,extraction time,liquid-to-material ratio and extraction temperature on the extraction yield of polyphenols were investigated using the Morus australis leaves as raw material and with the polyphenols yield as the response value. Moreover,the extraction technologies were designed and optimized by response surface experiment. Antioxidant activity of polyphenols was investigated by free radical removal method. The optimal extraction conditions were identified as follows:ethanol concentration 72%,extraction time 116 min,liquid-to-material ratio 37:1 mL/g,and extraction temperature 76℃. The extraction yield of polyphenols was 87.63 mg/g. Compared to the predictive value(87.97 mg/g),the relative error was 0.39%. The polyphenols had a scavenging effect and dose-effect on DPPH,OH and O₂- free radicals with IC₅₀ of 54.68 mg/L,207.16 mg/L and 416.05 mg/L respectively,which were lower than that of ascorbic acid. The model of optimization extraction technology of polyphenols from Morus australis leaves by response surface methodology was effective and highly accurate. Polyphenols obtained in this study had a certain antioxidant activity.