3种植物挥发油抑制食源性细菌生长活性成分及机理

Antibacterial Ingredients and Mechanism of Volatile Oils from Three Kinds of Plants against Foodborne Bacteria

采用无水乙醇浸法提取柠檬花、茶树叶、留兰香叶挥发油,用抑菌圈法及微量肉汤稀释法测定挥发油对大肠杆菌(Escherichia coli)、沙门氏菌(Salmonellas enteritidis)、金黄色葡萄球菌(Staphylococcus aureus)和李斯特菌(Listeria monocytogenes)的抑菌效果,并通过气相色谱-质谱联用分析其有效成分,抑菌机理通过实验菌菌液的电导率及扫描电子显微镜验证。结果表明:柠檬油、茶树油中有效抑菌成分分别为柠檬烯、1,8-桉叶素,其含量分别为65.50%、48.67%,留兰香油中有效抑菌成分为柠檬烯与左旋香芹酮,其含量分别为16.33%、35.67%。其中抑菌广谱性及抑菌效果最好的为留兰香油及其有效活性成分左旋香芹酮。实验中的有效活性物质可能是通过改变实验菌细胞膜的通透性,且可使细菌细胞发生皱缩破裂,以此起到抑菌及杀菌的作用。

The antibacterial effects of the volatile oils extracted with absolute ethanol from lemon flowers(Citrus limon),tea tree leaves(Melaleuca alternifolia)and spearmint leaves(Mentha spicata L.)against Escherichia coli,Staphylococcusaureus,Salmonellas enteritidis and Listeria monocytogenes were investigated in this study,and their active ingredients wereidentified by gas chromatography-mass spectrometry(GC-MS).Meanwhile,the antibacterial mechanism was evaluatedby determining the electric conductivity of bacterial suspensions and observing bacterial cells by scanning electronspectroscopy(SEM).The active ingredients were identified as cinene(65.50%)in lemon oil,1,8-cineole(48.67%)in tea treeoil,and cinene(16.33%)and L(-)-carvone(35.67%)in spearmint oil.Among these,spearmint oil and its L(-)-carvone hadthe broadest antibacterial spectrum and strongest antibacterial activity.SEM examination showed that the bacterial cells werecrumpled and ruptured after active ingredient treatment,demonstrating these substances could effectively suppress bacterialgrowth and reproduction by changing cell membrane permeability.