响应面试验优化乌梅熊果酸提取工艺及其对大肠杆菌的抑制作用  

Optimization of Ursolic Acid Extraction from Fructus Mume and Evaluation of Its Antibacterial Activity against Escherichia coli

作　　者：周茜[1] 韩雪[1] 韩晓梅[1] 闫晨静 白冰瑶 王唯霖 赵文[1] 

机构地区：[1]河北农业大学食品科技学院,河北保定071000

出　　处：《食品科学》2016年第8期67-73,共7页Food Science

基　　金：河北省科技计划项目(13226602D)

摘　　要：采用响应面法优化超声提取乌梅熊果酸的最佳条件。在单因素试验基础上,选择乙醇体积分数、料液比和超声时间为影响因素,以乌梅熊果酸提取量为响应值进行响应面分析;并研究了乌梅熊果酸对大肠杆菌的抑制作用。结果表明,乌梅熊果酸提取最佳工艺条件为乙醇体积分数71%、料液比3∶44(g/m L)、超声时间2.5 h,在此条件下提取量为(12.61±0.13)mg/g。乌梅熊果酸对大肠杆菌最低抑菌浓度为0.25 mg/m L;高剂量组(0.5 mg/m L)处理后与对照组相比,细胞壁和细胞膜通透性增加,培养液蛋白质含量、核酸大分子物质含量、Ca2^+浓度和总漏出率分别增加了28、1.5、7倍和0.8倍;扫描电镜观察菌体有明显变形或破碎现象,表明乌梅熊果酸对大肠杆菌生长具有抑制作用。The conditions for ultrasound-assisted extraction of ursolic acid from Fructus Mume were optimized by response surface methodology（RSM）.Based on the results of single-factor tests,three factors including ethanol concentration,solidto-liquid ratio and extraction time were identified as main variables that affect extraction efficiency.Optimization of the three factors was performed using extraction efficiency of ursolic acid as the response.Besides,the antibacterial effect of ursolic acid on Escherichia coli was studied.The optimum extraction conditions were determined as follows：ethanol concentration,71%;solid-to-liquid ratio,3：44（g/m L）;and extraction time,2.5 h.Under these conditions,the yield of ursolic acid was（12.61 ± 0.13）mg/g.The antibacterial test showed that the minimal inhibition concentration of ursolic acid against E.coli was 0.25 mg/m L.After treatment with 0.5 mg/m L ursolic acid,the cell wall and membrane permeability of E.coliwas increased and the contents of protein,nucleic acid materials,Ca2＋ and total leakage were enhanced by 29,2.5,8 and 1.8 folds compared to control,respectively.The scanning electron microscopic observation of E.coli showed that the cells were obviously destroyed or broken,indicating that ursolic acid has inhibitory effect on the growth of E.coli.The study can lay the theoretical basis for the application of ursolic acid and Fructus Mume in the future.

关 键 词：乌梅 熊果酸 响应面分析法 大肠杆菌 抑菌作用 

分 类 号：R284.5[医药卫生—中药学]