低温等离子体杀灭橙汁S.aureus的研究

Study on Pasteurization Law of S.aureus in Orange Juice using Low Temperature Plasma

非热杀菌能更好地提供产品质量,保留较好的营养成分,比传统杀菌技术更能节省能源,为开拓新的市场创造更大机遇。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DBDR所产生的低温等离子体(LTP)对鲜榨果汁的金黄色葡萄球菌(S.aureus)的杀菌规律。选取循环次数、pH、温度和电压4个因素进行中心组合设计,利用响应面对其杀菌规律进行研究,建立了低温等离子体(LTP)杀灭橙汁中S.aureus的二次多项数学模型,验证了模型的有效性,利用DesignExpert软件对其进行分析表明:循环7次,pH2.5,温度50℃,电压25kV时,杀菌率log(N0/N)最大,其预测值为5.19,与实测值相符。

With offering higher quality, better nutrition retention and more energy efficient compared with traditional thermal processes, non-thermal pasteurization processes have aroused great interest in food industry and consumers now. Non-thermal processes may also add value to the products, creating opportunities to open up new markets. 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. Cycles, pH, temperature and voltage four factors were investigated based on central composite design. The inactivation law of S. aureus in orange juice by low temperature plasma was studies and the second order quadratic equation for LTP inactivation was established by response surface methodology, and the effectiveness of this model was verified. Experimental data was analyzed by Design Expert software, when the results were 7 cycles, pH 2.5, temperature 50℃, and voltage 25 kV, the maximal log （N 0 /N） was 5.19, which were in consistent with the measured value.