高浓度臭氧水对巨大芽孢杆菌的杀菌效果及动力学模型

采用新型螺旋切割器作为气液分散装置制备的高浓度臭氧水作为杀菌剂,以年糕等米制品中难以杀灭的巨大芽孢杆菌作为研究对象,分析不同初始浓度、不同温度以及不同pH值的臭氧水对巨大芽孢杆菌的杀菌效果。试验结果表明:初始浓度为10 mg/L,温度为15℃,pH为5,杀菌时间为6 min时,臭氧水对巨大芽孢杆菌的杀菌数值可高达5.63 lg CFU/g。应用Weibull模型、Dose-response模型、一级动力学Linear模型对臭氧水在不同初始浓度下杀菌所得的试验数据进行拟合,并运用独立试验数据验证模型的准确度因素Af、偏移因素Bf、根平均方差RMSE和决定系数R2。通过对这三种模型的拟合参数的比较,结果表明在臭氧水初始浓度低于5 mg/L时适宜使用Weibull模型,在臭氧水初始浓度高于5 mg/L时使用Dose-response模型更合适。

Effect and Kinetic Models of High Concentration Ozone Water on Inactivation of Bacillus Megaterium

In this study,high concentration ozone water prepared by a new spiral cutter as a gas-liquid dispersing device was used as a fungicide,and the germicidal effects of ozone water with different initial concentration,temperature and pH value on giant bacillus were investigated by taking Bacillus Megaterium as research object which is difficult to kill in rice cakes and other foods.The results show that the bactericidal log value of ozone water on Bacillus megaterium could be as high as 5.63lg CFU/g when the initial ozone-water concentration was 10 mg/L,the temperature was 15℃,the pH was 5,and the sterilizing time was 6 min.Weibull model,Dose-response model and Linear first-order kinetic model were used to match the experimental data obtained from the sterilization of ozone water under different initial concentrations,and independent experimental data were used to verify the accuracy factor Af,deviation factor Bf,root mean variance RMSE and determination coefficient R2 of the model.By comparing the fitting parameters of the three models,the results show that the Weibull model was appropriate when the initial concentration of ozone water was lower than 5mg/L,and the Dose-response model was more appropriate when the initial concentration of ozone water was higher than 5mg/L.