五味子乙醇提取物的抑菌稳定性及抑菌机理研究

Study on the antimicrobial stability and antibacterial mechanism of ethanol extracts from fructus schisandrae chinensis

研究五味子乙醇提取物的抑菌稳定性、抑菌机理及在馒头贮藏保鲜中的应用.通过牛津杯法和二倍稀释法测得五味子乙醇提取物的最低抑菌浓度（MIC）在1.75～7mg/mL之间.探索了pH值、超声处理、贮藏时间以及食品体系中的葡萄糖、NaCl、金属离子等对五味子乙醇提取物对金黄色葡萄球菌、大肠杆菌、毛霉和曲霉的抑菌效果稳定性的影响.结果表明,五味子乙醇提取物抑菌稳定性受超声波影响不大,适合酸性食品的保鲜;抑菌活性随贮藏时间的延长逐渐减弱;葡萄糖有增加抑菌效果的作用;添加Fe^3＋、K^＋、Ca^2＋、Mg^2＋等金属离子的提取液对大肠杆菌和曲霉的抑制作用均有所增加,但除Fe^3＋外,添加其他三种金属离子的提取液对金黄色葡萄球菌的抑制作用有所减弱,对毛霉的抑制作用影响不明显;不同浓度的NaCl对五味子乙醇提取物抑菌作用的影响不同,且对不同菌种的影响也不同.电导率法得出五味子乙醇提取物的抑菌机制可能是其破坏了微生物细胞的膜结构,失去对微生物细胞的保护作用,从而达到抑菌目的.

The antimicrobial stabilities,mechanism of ethanol extracts from Fructus Schisandrae Chinensis (FSC)and its application on storage of steamed bread were studied in this article.The antibacterial effect and the minimal inhibitory concentration(MIC)of ethanol extracts from FSC were determined by the ox-ford cup method and two -fold dilution method,the results showed that the MIC were between 1.75 ~7mg/mL.By changing the pH value,ultrasonic treatment,extend the preservation time and adding glu-cose,NaCl,metal ions,discussed the stability of ethanol extract from FSC against staphylococcus aureus, escherichia coli,mucormucedo and aspergillus.The results showed that the antibacterial effect of ethanol extracts had good stability of the ultrasonic,and was suitable for the application of acidic foods;with the extension of time under normal temperature,the inhibitory effect was gradually weakened;the inhibitory effect of ethanol extract from FSC had synergistic effect with glucose;the inhibitory effects against Ee-scherichia coli and aspergillus increased when added metal ions,but besides Fe3 +,the inhibitory effect against staphylococcus aureus weakened and against mucormucedo was not obvious.The effects of different concentrations of NaCl on the antimicrobial activity were different.The antibacterial mechanism of ethanol extracts from FSC may be due to they destroyed the membrane structure of cells,providing a basis for the research of antibacterial mechanism.