响应面优化超声辅助提取黄瓜皮多酚工艺及其抗氧化活性研究

应用响应面法对超声波辅助提取黄瓜皮多酚的工艺进行优化,并对多酚的抗氧化活性进行了研究。以多酚提取率为响应值,选取超声温度、乙醇浓度、液料比、超声时间为自变量,应用Box-Behnken对试验进行设计和响应面优化,并通过多酚对羟自由基(·OH)和1,1-二苯基-2-三硝基苯肼自由基(DPPH·)的清除效果来评价其抗氧化活性。结果表明,黄瓜皮多酚的最佳提取工艺为:超声温度65℃,乙醇浓度62%,液料比26∶1(mL/g),超声时间31 min。在此条件下,测得多酚提取率实际值为(10.29±0.14)mg/g,理论值和实际值相对误差是0.39%,由此可以说明应用响应面法所得到的提取工艺参数可行性强、可靠性高。黄瓜皮多酚对·OH和DPPH·清除率的IC50值分别为116.60 mg/L和57.41 mg/L,表明黄瓜皮多酚具有较好的抗氧化活性,且抗氧化活性与多酚浓度呈正相关,该研究为将黄瓜皮多酚开发成天然抗氧剂提供理论基础。

Ultrasonic-Assisted Extraction Optimization of Polyphenols from Cucumber Peel via Response Surface Methodology and Their Antioxidant Activities

In the present study,the cucumber peel polyphenols was ultrasonic-assisted extracted and the extraction process was optimized through response surface methodology,and their antioxidant activities were further studied.The extraction yields of polyphenols were used as the response surface value in Box-Behnken design and response surface optimization,and the ultrasonic temperatures,ethanol concentrations,liquid-to-material ratios,and ultrasonic times were selected as independent variables,then the antioxidant activities of scavenging hydroxyl radicals(·OH)and 1,1-diphenyl-2-trinitrophenylhydrazine free redicals(DPPH·)were evaluated.The results showed that the optimal parameters for cucumber peel polyphenols extraction were determined as follows ultrasonic temperature of 65℃,ethanol concentration of 62%,liquid-to-material ratio of 26∶1(mL/g),and ultrasonic time of 31 min.Under these conditions,the actual value of polyphenols extraction yield was(10.29±0.14)mg/g,and the relative error between theoretical value and actual value was 0.39%,which indicated that the obtained extraction process parameters by response surface method were feasible with high reliability.The IC50 values of·OH and DPPH·scavenging rates of cucumber peel polyphenols were 116.60 mg/L and 57.41 mg/L,respectively,indicating that cucumber peel polyphenols showed good antioxidant activities,which was positively correlated with their concentrations.This study provided a theoretical basis for the development of cucumber peel polyphenols as natural antioxidants.