蛋白桑叶多酚提取工艺的优化及其抗氧化、抑菌活性

Extraction process optimization and anti-oxidant,anti-bacterial activities of polyphenols from Morus alba leaves

目的优化蛋白桑叶多酚提取工艺,并评价其抗氧化、抑菌活性。方法在单因素试验基础上,以十二烷基硫酸钠(SDS)用量、超声功率、超声温度、乙醇体积分数为影响因素,多酚含有量为评价指标,响应面法优化提取工艺。研究多酚还原能力、ABTS自由基清除能力,并检测其对大肠杆菌、金黄色葡萄球菌、普通变形杆菌、枯草芽孢杆菌、绿脓杆菌的抑制作用。结果最佳条件为超声时间15 min,料液比1∶25,SDS用量0.34%,超声功率250 W,超声温度60℃,乙醇体积分数50%,多酚质量分数达15.11 mg/g。多酚还原能力、ABTS自由基清除能力的IC50值分别为0.116、0.014 mg/mL,MIC值为0.2 mg/mL(大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌)或0.4 mg/mL(普通变形杆菌、绿脓杆菌)。结论该方法合理可行,可用于提取抗氧化、抑菌活性较强的蛋白桑叶多酚。

AIM To optimize the extraction process for polyphenols from Morus alba leaves and to evaluate their anti-oxidant,anti-bacterial activities.METHODS With sodium dodecyl sulfate(SDS)consumption,ultrasonic power,ultrasonic temperature and ethanol concentration as influencing factors,polyphenols yield as an evaluation index,the extraction process was optimized by response surface method on the basis of single factor test.The reducing capacity and ABTS free radical scavenging capacity of polyphenols were studied,along with the detection of their effects on inhibiting Escherichia coli,Staphylococcus aureus,Proteus vulgaris,Bacillus subtilis and Pseudomonas aeruginosa.RESULTS The optimal conditions were determined to be 15 min for ultrasonic time,1∶25 for solid-liquid ratio,0.34%for SDS consumption,250 W for ultrasonic power,60℃for ultrasonic temperature,and 50%for ethanol concentration,the polyphenols mass fraction reached 15.11 mg/g.The reducing capacity,ABTS free radical scavenging capacity of polyphenols demonstrated the IC50 values of 0.116,0.014 mg/mL,respectively,along with the MIC value of 0.2 mg/mL(E.coli,S.aureus,B.subtilis)or 0.4 mg/mL(P.vulgaris,P.aeruginos).CONCLUSION This reasonable and feasible method can be used for the extraction of polyphenols with strong anti-oxidant,anti-bacterial activities from M.alba leaves.