高压脉冲电场用于黄酒灭菌过程的多物理场耦合建模和细胞膜微观特性变化机理的研究

As a symbol of Chinese civilization, the Chinese rice wine is set of nutrition and health on the whole, well received by the consumers in China. Considering the microbial contamination during the traditional processing of Chinese rice wine, as well as the enormous potential of pulsed electric field (PEF) technology in the non-thermal processing of liquid food, scientific studies are proposed on the multi-physics coupled simulation in the PEF system and the mechanism of the changes in the microcosmic characteristics of microbial envelope during the rice wine sterilization processing by PEF technology. First, the PEF system for Chinese rice wine processing is established, then the multi-physics coupled model is developed for optimizing the process environment inside the treatment system. The microcosmic characteristics of microbial envelope are investigated by using morphology and characteristic parameters from atomic force microscopy (AFM) images and force measurements under liquid, respectively. The kinetic models for Chinese rice wine sterilization is studied through quantitative detection of microorganisms by AFM images. Thus the mechanism of PEF processing will be revealed from both micro and macro point of view. In order to describe the microbial reduction based on the distribution discipline of various physical fields and processing operation parameters, the quantitative prediction model is constructed through a combination of both two models mentioned above: the multi-physics coupled model and the kinetic model for microbial inactivation. Finally, the strategy of Chinese rice wine processing by PEF technology is proposed. It may provide new ideas and theoretical basis for the wide application of PEF technology in the liquid food processing.

作为中华文明的象征，黄酒集营养和保健于一体，深受广大消费者的喜爱。针对传统黄酒酿造过程中的微生物污染问题和高压脉冲电场（Pulsed Electric Field，简称PEF）技术在非热加工领域的巨大潜力，提出PEF用于黄酒灭菌过程的多物理场耦合建模和细胞膜微观特性变化机理的研究。首先构建适用于黄酒灭菌的PEF处理系统，建立多物理场耦合模型并优化处理系统，采用原子力显微镜成像技术进行细胞膜的微观特性（形貌和力学特性）的分析，采用基于原子力显微镜图像的微生物定量检测方法探索PEF对黄酒灭菌的动力学模型，从微观和宏观角度分别研究PEF技术的灭菌机理，通过将上述多物理场耦合模型和灭菌动力学模型相结合，构建基于各物理场分布规律和处理工作参数的PEF技术对黄酒灭菌的定量预测模型。最后，结合以上结果，提出PEF技术用于黄酒加工的策略，为PEF技术在液态食品加工领域的广泛应用提供新的思路和理论依据。

作为中华文明的象征，黄酒集营养和保健于一体，深受广大消费者的喜爱。针对传统黄酒酿造过程中的微生物污染问题和高压脉冲电场技术在非热加工领域的巨大潜力，提出了将高压脉冲电场用于黄酒灭菌过程的研究。首先，改进了实验室原有高压脉冲电场灭菌处理系统，搭建了在线温度监测系统。分析了不同处理室结构和物料流动状态对共场型连续式处理室内部各物理场分布规律的影响。通过建立多物理场耦合模型，可以对高压脉冲电场处理室内部的物理量进行分析，得到电场强度、能量输入和温度升高与处理室结构参数的关系。然后通过数值模拟方法，建立了准方波脉冲波形的下降时间与处理介质流量和初始温度之间的相关性。分析了不同微生物细胞的形态特性对于高压脉冲电场技术杀菌效果的影响。较大的细胞尺寸可以增加跨膜电势和细胞膜的电场强度，使细胞对于高压脉冲电场处理更为敏感。分析了高压脉冲电场技术的不同处理工作参数对微生物的致死规律。在一定范围的处理强度（电场强度为12–21 kV/cm，处理时间为30–180 μs）和初始温度（25–35 °C）下，研究高压脉冲电场技术对黄酒中酿酒酵母菌的致死作用，得到最大的杀菌效果为5.5个对数级。从AFM成像的结果可以看出，经过处理后微生物细胞的数量减少，图像呈现模糊的边界，细胞边缘塌陷，表明高压脉冲电场技术引起了酵母菌细胞膜的破坏。探索了将多物理场耦合模型和杀菌动力学模型相结合，构建基于处理室结构参数和处理过程工作参数的高压脉冲电场技术的杀菌效果预测模型的可行性。最后，对经过高压脉冲电场处理后的黄酒的品质指标进行了分析，相对于巴氏杀菌技术，高压脉冲电场技术可以有效减少品质下降。以上结果为高压脉冲电场 技术在黄酒加工领域的广泛应用提供新的思路和理论依据。