低温等离子体对生鲜牛肉杀菌效果及色泽的影响

为探讨低温等离子体在不显著影响牛肉色泽的条件下对牛肉杀菌的最优工艺,在单因素试验的基础上,采用Box-Behnken响应面法研究了电压、处理时间与O_2比例对杀菌率及红度a*值的影响,模拟得到了二次多项式回归方程的预测模型。结果表明低温等离子体能有效降低牛肉细菌残留量,最佳杀菌工艺为:电压72 kV,处理时间86 s,O_2、CO_2和N_2比例分别为35%、35%和30%。在此条件下,牛肉仍保持较好的颜色,杀菌率为93.75%,与模型预测值94.04%吻合良好,说明优化出的回归方程对于生产实际有一定的理论指导意义。

Effect of Cold Plasma on Sterilization and Color of Fresh Beef

In order to obtain the optimal sterilization conditions for fresh beef with a cold plasma system, where beef color is not significantly impacted, the sterilization efficiency and redness (a*) value were optimized as a function of voltage, treatment time and O2 percentage using a combination of one-factor-at-a-time method and response surface methodology with a Box-Behnken design. A quadratic polynomial regression equation to predict the two response variables was fitted. The results showed that cold plasma could effectively reduce the total viable count of beef, and a voltage of 72 kV, a processing time of 86 s and an atmosphere consisting of 35% O2, 35% CO2 and 30% N2 were found to be the optimal conditions to obtain a higher sterilization efficiency of 93.75%, agreeing with the predicted value (94.04%). The optimization model proposed in this study can provide a useful guideline for practical application of cold plasma as a sterilization technology.