红薯叶黄酮超声提取工艺优化、抗氧化及抑菌研究

Optimization of ultrasonic extraction process of flavonoids from sweet potato leaves and its antioxidative and antibacterial ability

以红薯叶为原料,采用超声辅助提取,以单因素实验为基础,结合响应面法优化红薯叶中黄酮提取工艺参数,并测定其体外抗氧化活性及抑菌作用。结果表明,红薯叶黄酮超声提取最佳条件为:料液比1∶19,超声温度42℃,提取时间42 min,乙醇体积分数58%,红薯叶总黄酮提取率为2.611%±0.032%;红薯叶黄酮提取物具有一定的抗氧化性及抑菌作用,对DPPH和ABTS自由基清除率的IC_(50)分别为0.3382 mg/mL和0.4538 mg/mL;对金黄色葡萄球菌和大肠杆菌的MIC分别为0.084 mg/mL和0.168 mg/mL。

Sweet potato leaves was used as raw material and ultrasonic-assisted extraction was applied. Based on single factor experiments,combined with response surface methodology,the extraction process parameters of flavonoids from sweet potato leaves were optimized,and in vitro antioxidant activities and antibacterial effects were determined. The results showed that the optimal conditions for ultrasonic extraction of flavonoids were:solid-liquid ratio 1∶19,ultrasonic temperature 42℃,extraction time 42min,and ethanol volume fraction 58%. Under the above conditions,the extraction rate of total flavonoids from sweet potato leaves was 2.611±0.032%. Sweet potato leaves flavonoid extract has certain antioxidant and antibacterial effects. IC_(50)for free radical scavenging of DPPH and ABTS were 0.3382 and 0.4538 mg/mL,respectively. The MICs against S. aureus and E. coli were 0.084 and 0.168 mg/mL,respectively.