UV Sterilization Incorporated with Spraying Process for Liquid Foods

农产品和食品的质量安全问题备受关注。灭菌是保持食品质量和安全的最有效的过程。在几种杀菌方法中，紫外线(UV)是一种简单、经济、安全的杀菌方法。然而，紫外线对材料的透过率很低，目前紫外线照射仅限于食品或容器表面、水和环境空气的杀菌。这项研究旨在将具有几个优点的紫外线辐射应用于涉及色素和饮食的液体食品。即确定了紫外光照射和杀菌的特点以及两者之间的关系。为了提高液体食品的表观紫外线透过率，提出了液体食品喷雾的概念，并建立了喷雾杀菌系统。阐明了喷雾压力与灭菌率之间的关系，为该系统的开发提供了基础数据。…研究结果总结如下：1.研究对象液体食品的紫外线透过率随物质浓度的增加呈指数下降。液体食品的光程长度与紫外光透过率之间呈指数函数关系。由紫外线照射下的微生物生长曲线得到的存活率与液体食品的光程长度呈线性关系。紫外线透过率和紫外线灭菌成活率与Log-Log切片纸上的两条直线有关。从理论上证实了提高喷雾压力可以减小喷雾后液体食品的颗粒尺寸。喷雾压力与紫外线杀菌率的关系取决于液体食品的特性。紫外灯功率越大，照射时间或喷洒面积越长，系统的适用性增加越少。

There is a great concern on quality and security of agricultural products and foods. Sterilization is the most effective process to maintain food quality and security. Among some sterilization processes, ultra violet (UV) irradiation is known to be easy, economical and safe sterilization process. However the transmissivity of UV to material is low, UV irradiation has been limited to the sterilization of food or container surface, water and ambient air. This research aimed to apply the UV irradiation with several advantages to liquid foods that involved colorings and diets. Namely the characteristics of UV irradiation and sterilization were determined as well as the relation between them. An idea to spray the liquid foods was proposed to increase the apparent UV transmissivity and UV sterilization system with spraying process was constructed. The relation between the spraying pressure and the sterilization ratio was elucidated to have fundamental data for the development of the system. … More The obtained results ware summarized as follows :1. The UV transmissivity for the subject liquid foods decreased exponentially with the increase in the concentration of the materials.2. The relationships between the optical path length and UV transmissivity for the liquid foods were correlated with the exponential function.3. The survival ratios obtained by the microbial growth curves under the UV irradiation showed the linear relationship with the optical path length of the liquid foods.4. The UV transmissivity and the survival ratio by UV sterilization had relations with two straight lines on the Log-Log section paper.5. The increase in spraying pressure was theoretically confirmed to decrease the particle size of the sprayed liquid foods.6. The relationship between the spraying pressure and the UV sterilization ratio depended on the characteristics of liquid foods.7. UV lamps with higher power and extension of irradiation time or spraying area would increase the applicability of the system Less