欧姆加热杀菌对豆浆中微生物菌落总数的影响

Effect of Ohmic Heating Sterilization on the Bacteria Counts in Soymilk

利用响应面法分析方法,优化了欧姆加热技术对豆浆的杀菌工艺参数。在单因素实验的基础上,选择加热温度、电压和电场频率为影响因素,以豆浆中微生物的杀灭率为响应值,利用Box-Behnken实验设计建立数学模型,进行响应面分析。结果表明:3个因素对豆浆中微生物菌群杀菌效果的影响大小次序为:加热温度>电压>电场频率。当欧姆加热的加热温度为82℃,电压为200 V,电场频率为190 Hz时,对豆浆中微生物菌群的杀灭效果最佳,该条件下欧姆加热对豆浆中微生物的杀灭率可达100%,与模型预测值相近;所得方程显著,拟合情况良好。杀菌后豆浆中的微生物残留量远小于1500 CFU/g,符合食品安全的相关规定。研究结果可为欧姆加热杀菌技术在豆浆加工业中的应用提供理论依据。

The ohmic heating parameters for sterilizing the soymilk were optimized by response surface methodology（ RSM）.The effect of temperature,electric voltage and frequency of ohmic heating on the bactericidal rate of the bacteria counts in soymilk was investigated on the base of single factor experiment. Corresponding mathematical model was established by using Box-Behnken design.The results showed that the effect order of three factors was as followed： temperature voltage frequency.The optimal specifications of ohmic heating were determined as 82 ℃,200 V and 190 Hz for temperature,voltage and frequency,respectively.Under the optimized conditions,bacteria sterilization rate could reach to be 100% which was similar to the model predictions.The regression equation was significant,and the mathematical model for the simulation was presented.The number of residual bacterial counts in the soymilk was far less than 1500 CFU/g,meeting the relevant national standards of food safety.The results could provide a theoretical basis for the application of ohmic heating sterilization technology in soymilk processing industry.