交流电场杀菌对酵母菌杀死率的影响

Effect of AC Electric Field Sterilization on the Killing Rate of Yeasts

杀菌工艺是食品加工的重要环节,传统的热杀菌会导致食品的色泽、风味和营养物质不同程度的改变和损失。因此,非热杀菌技术应运而生,其中,脉冲电场杀菌技术利用高电压脉冲作用于物料,使微生物细胞膜被电击穿,产生不可修复的穿孔,导致微生物失活,而达到杀菌效果。本研究利用交流电使电极间产生类似脉冲电场的高电场,使其作用于酵母菌液进行杀菌处理,研究温度、杀菌时间、液体流速、电场强度等因素对杀菌效果的影响,从而寻找最佳杀菌工艺参数,为格瓦斯的杀菌工艺提供理论参考。试验表明,最佳杀菌工艺参数为:温度为40℃、杀菌时间为80 s、液体流速为100 m L/min、电场强度为10 k V/cm,采用最佳工艺进行杀菌处理,其酵母菌死菌率达到95.5%。说明该交流电场杀菌设备可有效杀灭酵母菌,具有一定的杀菌能力。

The sterilization process is an important part of food processing,traditional thermal sterilization in killing spoilage microorganisms at the same time,can cause food color,flavor and nutrients varying degrees of change and loss. There fore,non-thermal sterilization technology emerges as the times require and continue to develop,where electric field sterilization technology utilizes high-voltage pulse applied to the material,microbial membrane electrical breakdown in the strong electric field,produce irreparable perforation,lead to microbial inactivation,and reach the effect of sterilization. In this study,the high electric field strength caused by alternating current was used to process the sterilization of liquid yeast,the effects of temperature,sterilization time,liquid velocity and electric field strength of the raw materials on the sterilization were studied,in order to find the best sterilization process parameters,as to provide theoretical basis for food sterilization technology. Experiment showed that the optimum parameters of the sterilization process was：raw material liquid temperature of40 ℃,sterilization time of 80 s,liquid flow rate of 100 m L/min,the electric field intensity of 10 k V/cm,the optimum technology was adopted to improve the sterilization,the death rate of yeast bacterium reached to 95.5 %.This study showed that the ac electric field sterilization equipment could effectively kill yeast,had certain ability of sterilization.