利用介质阻挡放电等离子体杀灭鲜榨果汁大肠杆菌

    Inactivation of E.coli in fresh fruit juice using dielectric barrier discharge plasma (DBDP)

    • 摘要: 与传统热杀菌相比,非热杀菌能较大程度地保持食品中营养成分,节约能耗。为了进一步研究非热杀菌技术,利用自行设计的介质阻挡放电反应器(DBDR),以鲜榨果汁为杀菌介质,研究了DBDR所产生的低温等离子体(LTP)的杀菌效果和对鲜榨果汁品质的影响。采用响应面法建立了介质阻挡放电等离子体(DBDP)杀灭鲜榨果汁饮料中大肠杆菌的二次多项数学模型,验证了模型的有效性,并探讨了循环次数、pH值、温度及电压对DBDP杀灭大肠杆菌的影响,优化出杀灭7个数量级大肠杆菌(E.coli)ATCC 8739的工艺参数为:循环次数6次,pH值 3.14,温度39.72℃,电压21.42 kV。为进一步研究DBDP的杀菌规律和探讨杀菌机理奠定了数学基础,同时,此模型的决定系数R2达到0.9817,可推广应用到其他果蔬汁的杀菌处理,提高鲜榨果蔬汁的品质和质量安全。

       

      Abstract: Non-thermal pasteurization processes can offer higher quality, better nutrition retention and more energy efficient compared with traditional thermal processes. In this paper, dielectric barrier discharge reactor (DBDR) was designed. And the bactericidal efficiency of low-temperature plasma (LTP) produced by DBDR on fresh juice and its impacts on the quality of juice were researched. The second order quadratic equation for DBDR inactivation was established by response surface methodology, and the effectiveness of this model was verified. Also, effects of cycles, pH value, temperature and voltage on DBDP sterilization of E.coli were discussed. Based on the exploration, the optimum conditions for inactivation of E.coli ATCC 8739 of seven log cycles were obtained as: 6 cycles, pH 3.14, temperature 39.72℃, and voltage 21.42 kV. It lays a foundation for further studying on the DBDP sterilization law and the mechanism of sterilization. While the correlation coefficient R2 for this model equals to 0.9817, the low-temperature plasma (LTP) produced by DBDR can be applied to other fruit and vegetable disinfection treatment and improve the quality and safty of fresh fruit and vegetable.

       

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