title: Application of low frequency pulsed ohmic heating for inactivation of foodborne pathogens and MS-2 phage in buffered peptone water and tomato juice.
abstract: 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.
authors.affiliation: 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.
authors.forename: Sang-Soon
authors.initials: SS
authors.lastname: Kim
authors.affiliation: Department of Rural Systems Engineering, College of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea.
authors.forename: Won
authors.initials: W
authors.lastname: Choi
authors.affiliation: 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. Electronic address: kang7820@snu.ac.kr.
authors.forename: Dong-Hyun
authors.initials: DH
authors.lastname: Kang
mesh_terms: D001419:Bacteria / Q000528:radiation effects*; D001435:Bacteriophages / Q000528:radiation effects*; D002338:Carotenoids / Q000032:analysis; D003116:Color; D004203:Disinfection / Q000379:methods; D004566:Electrodes; D019453:Escherichia coli O157 / Q000528:radiation effects; D005516:Food Microbiology / Q000379:methods; D000067030:Fruit and Vegetable Juices / Q000032:analysis / Q000382:microbiology*; D006361:Heating; D006358:Hot Temperature; D008089:Listeria monocytogenes / Q000528:radiation effects; D000077276:Lycopene; D018551:Solanum lycopersicum / Q000382:microbiology; D050296:Microbial Viability; D010461:Peptones; D012486:Salmonella typhimurium / Q000502:physiology / Q000528:radiation effects; D038301:Virus Inactivation
chemical_list: D010461:Peptones; D002338:Carotenoids; D000077276:Lycopene
keywords: Electrode corrosion; Frequency; Pathogens inactivation; Pulsed ohmic heating; Sub-lethal injury; Tomato juice