高压热杀菌结合酸对枯草杆菌芽孢的杀灭作用  

Effects of high-pressure thermal sterilization combining with acid on the sterilization of Bacillus subtilis spores

作　　者：章中[1] 杨杰[1] 申瑾 毕可 刘月 辛伟山 张变飞 ZHANG Zhong;YANG Jie;SHEN Jin;BI Ke;LIU Yue;XIN Weishan;ZHANG Bianfei(School of Food and Wine,Ningxia University,Yinchuan 750021,China)

机构地区：[1]宁夏大学食品与葡萄酒学院,宁夏银川750021

出　　处：《食品与发酵工业》2022年第12期9-15,共7页Food and Fermentation Industries

基　　金：国家自然科学基金项目(31760474);国家自然科学基金项目(31460410)。

摘　　要：高压热杀菌(high-pressure thermal sterilization,HPTS)能够有效的杀灭食品中最难杀死的芽孢,研究表明,HPTS结合酸处理能取得更好的杀灭效果。为明确HPTS结合酸杀灭芽孢的机理,该研究调整芽孢悬浮液的pH值为1、4、7,于550 MPa结合25、65、75℃处理20 min。采用平板计数法、紫外分光光度法、流式细胞术和傅里叶红外变换光谱对HPTS结合酸处理后枯草杆菌芽孢的杀灭率、紫外吸收泄漏量、内膜通透性及芽孢成分变化进行研究。结果表明,随着pH值降低,HPTS结合酸对芽孢的杀灭作用明显增强,芽孢最多被杀灭了6.25 lgCFU/mL;紫外吸收泄漏量及内膜通透性都显著增加;同时芽孢内膜磷脂相态发生转变,膜脂流动性增加;蛋白质二级结构变化,导致蛋白变性;核酸物质变性,皮层肽聚糖和细胞壁结构改变。综上,酸处理是辅助HPTS杀灭芽孢的有效手段,两者具有良好的协同杀菌作用。High-pressure thermal sterilization(HPTS)is effective in inactivating the most difficult-to-inactivate bacterial spores in foods,and studies have shown that HPTS combined with acid treatment can achieve better inactivating effect.To clarify the mechanism of inactivating bacterial spores by HPTS combined with acid,the pH of the bacterium suspension was adjusted to 1,4 and 7,and the suspension was treated at 550 MPa combined with 25,65 and 75℃for 20 min in this study.The killing effect,UV absorption leakage,inner membrane permeability and changes in spore composition of Bacillus subtilis after HPTS combined with acid treatment were investigated by plate counting,UV spectrophotometry,flow cytometry and Fourier infrared transform spectroscopy.It was found that:(1)Under normal temperature and pressure,the pH value alone could not cause the inactivation of bacterial spores.The inactivating effect of HPTS combining with acid on bacterial spores increased effectively with the decreasing of pH,and bacterial spores were inactivated by up to 6.25 lgCFU/mL.(2)The UV absorption leakage reflects the changes in the permeability of the inner membrane of bacterial spores.OD_(260) and OD_(280) values increased significantly after HPTS combined with different pH treatments,the UV absorption leakage of bacterial spores increased,indicating that HPTS combined with different pH caused some degree of damage to the permeability barrier of bacterial spores.As the pH decreased,the amount of UV-absorbing material leaked from bacterial spores after 550 MPa combined with 25℃/65℃/75℃treatment increased significantly,indicating that acid would further damage the permeation barrier of bacterial spores,allowing more nucleic acid and protein-based UV absorbers to leak out.(3)Flow cytometry is commonly used to detect damage to bacterial cell membranes.The bacterial spores were stained with the fluorescent dye PI,which releases red fluorescence after embedding double-stranded DNA.Compared to the action of HPTS alone,the proportion of positi

关 键 词：高压热杀菌 酸 膜通透性 膜流动性 芽胞 傅里叶红外光谱 

分 类 号：TS201.3[轻工技术与工程—食品科学]