Kim Sang-Soon, Choi Won, Kang Dong-Hyun
Department of Agricultural Biotechnology, Center for Food and Bioconvergence, and Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea; Institutes of Green Bio Science & Technology, Seoul National University, Pyeongchang-gun, Gangwon-do, 25354, Republic of Korea.
Department of Rural Systems Engineering, College of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea.
Food Microbiol. 2017 May;63:22-27. doi: 10.1016/j.fm.2016.10.021. Epub 2016 Oct 11.
The purpose of this study was to inactivate foodborne pathogens effectively by ohmic heating in buffered peptone water and tomato juice without causing electrode corrosion and quality degradation. Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes were used as representative foodborne pathogens and MS-2 phage was used as a norovirus surrogate. Buffered peptone water and tomato juice inoculated with pathogens were treated with pulsed ohmic heating at different frequencies (0.06-1 kHz). Propidium iodide uptake values of bacterial pathogens were significantly (p < 0.05) larger at 0.06-0.5 kHz than at 1 kHz, and sub-lethal injury of pathogenic bacteria was reduced by decreasing frequency. MS-2 phage was inactivated more effectively at low frequency, and was more sensitive to acidic conditions than pathogenic bacteria. Electrode corrosion and quality degradation of tomato juice were not observed regardless of frequency. This study suggests that low frequency pulsed ohmic heating is applicable to inactivate foodborne pathogens effectively without causing electrode corrosion and quality degradation in tomato juice.
本研究的目的是通过在缓冲蛋白胨水和番茄汁中进行欧姆加热来有效灭活食源性病原体，同时不引起电极腐蚀和质量下降。以大肠杆菌O157:H7、鼠伤寒沙门氏菌和单核细胞增生李斯特菌作为代表性食源性病原体，并使用MS-2噬菌体作为诺如病毒的替代物。对接种了病原体的缓冲蛋白胨水和番茄汁进行不同频率（0.06 - 1kHz）的脉冲欧姆加热处理。在0.06 - 0.5kHz时，细菌病原体的碘化丙啶摄取值显著（p < 0.05）高于1kHz时，并且通过降低频率可减少病原菌的亚致死损伤。MS-2噬菌体在低频下更有效地被灭活，并且比病原菌对酸性条件更敏感。无论频率如何，均未观察到番茄汁的电极腐蚀和质量下降。本研究表明，低频脉冲欧姆加热适用于有效灭活食源性病原体，且不会在番茄汁中引起电极腐蚀和质量下降。
