摘要
枯草杆菌芽孢是极难被杀灭的细菌之一,为探究山梨酸钾与压力辅助热杀菌(pressure assisted thermal sterilization,PATS)对枯草杆菌芽孢的联合作用效果,该研究以OD600值(optical density at 600 nm)、OD_(260)值(optical density at 260 nm)、OD_(280)值(optical density at 280 nm)、2,6-吡啶二羧酸释放率表征芽孢内容物的释放情况,扫描电镜、流式细胞术、傅里叶红外光谱仪、激光粒度仪检测芽孢结构变化情况。结果表明,山梨酸钾强化了PATS的杀菌效果,200 MPa-75℃处理杀灭了2.63 lg CFU/mL芽孢,添加2 g/L山梨酸钾后,杀灭了3.24 lg CFU/mL芽孢。较单独PATS处理,添加山梨酸钾后,促进了芽孢内容物的释放,内膜通透性增加,芽孢粒径显著减小,内膜、细胞壁等结构受损程度加剧。同时,Na^(+)/K^(+)-ATPase活力显著降低,膜电位平衡被破坏,基本生理代谢功能紊乱。总之,PATS结合山梨酸钾对枯草芽孢杆菌芽孢有协同杀菌作用,且随着山梨酸钾添加量或温度的升高而增强,有利于促进该技术在食品杀菌中的应用。
Bacterial spores are formed by cells of Clostridium,Bacillus and related genera as a response to a lack of one or more nutrients.These spores are dormant and resistant to inactivation treatments,including heat,radiation,preservatives,and high-pressure.Particularly,spores can germinate and develop in food products,resulting in the food spoilage or instances of foodborne illness.Bacillus subtilis spores are inactivated in food at high temperatures exceeding 100℃during the traditional food processing.Nevertheless,high temperatures can pose a significant impact on food quality.This study aims to mitigate this temperature effect for the lower sterilization temperature.Potassium sorbate was integrated with PATS(pressure assisted thermal sterilization)into inactivate Bacillus subtilis spores.The release of important intraspore substances was established by spectrophotometry testing the OD_(600)(optical density at 600 nm)value,OD260(optical density at 260 nm)value,OD_(280)(optical density at 280 nm)value,and DPA(2,6-pyridine dicarboxylic acid)levels.And the spore structure was examined via SEM(scanning electron microscopy),flow cytometry,FTIR(Fourier transform infrared spectroscopy),and PSD(particle size distribution analysis).The addition of potassium sorbate was improved the sporicidal effect of PATS.The surviving spores plate counting demonstrated that the initial viable spore concentration was approximately 1.5×10^(8) CFU/mL.Treatment with 200 MPa-75℃inactivated 2.63 lg CFU/mLspores,and the combined treatment of 200 MPa-75℃and 2 g/L potassium sorbate inactivated 3.24 lg CFU/mLspores.The untreated spore suspensions displayed OD600,OD260,and OD280 values of 1,0.053,and 0.046,respectively.Following a spore suspension treatment of 200 MPa-75℃-2 g/L potassium sorbate,the OD600 value declined by 0.413,while the OD260 and OD280 values increased to 0.401 and 0.290,respectively.It was indicated that the addition of potassium sorbate was enhanced the liberation of protein and nucleic acid in spores,leading to the redu
作者
李佳佳
杨杰
章中
王旭娟
武思睿
LI Jiajia;YANG Jie;ZHANG Zhong;WANG Xujuan;WU Sirui(College of Food Science and Engineering,Ningxia University,Yinchuan 750000,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2023年第22期287-295,共9页
Transactions of the Chinese Society of Agricultural Engineering
基金
宁夏自然科学基金项目(2023AAC03136)
国家自然科学基金项目(31760474
32260633)。
关键词
山梨酸钾
温度
扫描电镜
枯草芽孢杆菌
芽孢
内膜
PATS
potassium sorbate
temperature
scaning electron microscopy
Bacillus subtilis
spore
inner membrane
PATS
