摘要
[目的]研究表没食子儿茶素没食子酸酯(EGCG)对金黄色葡萄球菌(S.aureus)和沙门氏菌(S.typhimurium)的抑菌机理,以及对紫淮山片中S.aureus和S.typhimurium的清除效果。[方法]通过微量肉汤梯度稀释法确定EGCG的体外抑菌效果,并进一步通过钾离子测定、PI染色、OD_(260 nm)值、OD_(280 nm)值以及细胞形态观察明确EGCG的抑菌机制。最后探讨EGCG结合巴氏杀菌对紫淮山片中S.aureus和S.typhimurium的清除率。[结果]EGCG对S.aureus和S.typhimurium的最小抑菌质量浓度(MIC)分别为0.512,0.256 mg/mL,最小杀菌质量浓度分别为1.024,0.512 mg/mL。S.aureus经MIC和2MIC处理后,K^(+)质量浓度分别上升到2.26,2.39 mg/L,而S.typhimurium经MIC及2MIC处理后,K^(+)质量浓度分别上升到1.79,1.84 mg/L,均高于未经EGCG处理的菌株。EGCG能破坏S.aureus和S.typhimurium细胞膜,促使细胞膜通透性增加,进而出现细胞内容物泄露以及细胞皱缩的现象,最终导致细菌死亡。2MIC EGCG结合巴氏杀菌处理对紫淮山片中S.aureus和S.typhimurium清除率达到100%。[结论]EGCG对食源性致病菌具有体外抑菌效果,可作为天然抑菌保鲜剂应用于食品中。
[Objective]The bacteriostatic mechanism of epigallocatechin gallate(EGCG)against Staphylococcus aureus(S.aureus)and Salmonella typhimurium(S.typhimurium)and the elimination effect of S.aureus and S.typhimurium in purple yam chip were studied.[Methods]The bacteriostatic effect of EGCG in vitro was determined by microbroth gradient dilution method,and the bacteriostatic mechanism of EGCG was further determined by potassium ion determination,PI staining,OD_(260 nm) value,OD_(280 nm) value and cell morphology observation.Finally,the clearance rate of S.aureus and S.typhimurium in purple yam chip was studied by EGCG combined with pasteurization.[Results]The minimum inhibitory concentration(MIC)of EGCG for S.aureus and S.typhimurium was 0.512 mg/mL and 0.256 mg/mL,and the minimum bactericidal concentration was 1.024 mg/mL and 0.512 mg/mL,respectively.After MIC and 2MIC treatment,the K^(+)concentration of S.aureus increased to 2.26 mg/L and 2.39 mg/L,respectively,while after MIC and 2MIC treatment,the K^(+)concentration of S.typhimurium increased to 1.79 mg/L and 1.84 mg/L,respectively.All strains were higher than those without EGCG treatment.EGCG could destroy the cell membranes of S.aureus and S.typhimurium,promote the increase of membrane permeability,and then appear the phenomenon of cell contents leakage and cell shrinkage,resulting in bacterial death.The clearance rate of S.aureus and S.typhimurium in purple yam chip was 100%after treatment with EGCG at MIC combined with pasteurization.[Conclusion]EGCG has antibacterial effect on foodborne pathogens in vitro,and can be used as a natural antibacterial preservative in food.
作者
陈小敏
黄泽璇
谭礼浩
余以刚
CHEN Xiaomin;HUANG Zexuan;TAN Lihao;YU Yigang(Guangdong Technician College of Light Industry,Guangzhou,Guangdong 511330,China;College of Food Science and Engineering,South China University of Technology,Guangzhou,Guangdong 510006,China;Guangzhou Technician College,Guangzhou,Guangdong 510000,China)
出处
《食品与机械》
CSCD
北大核心
2024年第8期127-134,共8页
Food and Machinery
基金
广州市科技计划项目(编号:202206010177)
广东省农业农村厅农业科研类及技术推广示范类项目(编号:2023-440000-58010200-9645)。
