title: Combination effect of ozone and heat treatments for the inactivation of Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes in apple juice.
abstract: We investigated the combination effect of ozone and heat treatments in apple juice for the inactivation of Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes. Apple juices inoculated with the three pathogens were treated with gaseous ozone and heat simultaneously for up to 1 min. Gaseous ozone treatment was progressed at a flow rate of 3.0 l/min with a concentration of 2.0-3.0 g/m³ and heat treatment was performed at temperatures of 25, 45, 50, and 55 °C. Populations of surviving pathogens decreased in all samples as treatment temperature increased from 25 to 55 °C. Heat treatment alone (25, 45, 50 and 55 °C) resulted in 0.20, 0.37, 2.16 and 2.54 log CFU/ml reductions of E. coli O157:H7, respectively, in apple juice. Combination treatment of ozone and heat for 1 min reduced this pathogen by 1.50 and 1.60 log CFU/ml, respectively, at 25 and 45 °C, and below the detection limit (1 log CFU/ml) at 50 and 55 °C. We found a synergistic effect in the inactivation of pathogens in apple juice treated with ozone and heated at 50 °C. The reduction trend of S. Typhimurium and L. monocytogenes in apple juice was similar to that of E. coli O157:H7. There were no significant changes of Hunter color values when apple juices were treated with heat only and the combination of ozone and heat. Residual ozone was measured following ozone treatment. In all ozone treated samples, the concentration of residual ozone was reduced to under acceptable levels (<0.4 mg/l). In conclusion, the combination treatment of ozone and heat was significantly effective in the inactivation of foodborne pathogens while maintaining acceptable apple juice quality.
authors.affiliation: Department of Food and Animal Biotechnology, School of Agricultural Biotechnology, Center for Food and Bioconvergence, and Research Institute for Agricultural and Life Science, Seoul National University, San 56-1, Sillim-dong, Kwanak-gu, Seoul 151-742, Republic of Korea; Department of Food Science and Technology, College of Agriculture and Life Sciences, Chonbuk National University, Jeonju, Republic of Korea.
authors.forename: Hye-Jung
authors.initials: HJ
authors.lastname: Sung
authors.affiliation: Department of Food and Animal Biotechnology, School of Agricultural Biotechnology, Center for Food and Bioconvergence, and Research Institute for Agricultural and Life Science, Seoul National University, San 56-1, Sillim-dong, Kwanak-gu, Seoul 151-742, Republic of Korea; Department of Food Science and Technology, College of Agriculture and Life Sciences, Chonbuk National University, Jeonju, Republic of Korea.
authors.forename: Won-Jae
authors.initials: WJ
authors.lastname: Song
authors.affiliation: Department of Food Science and Technology, College of Agriculture and Life Sciences, Chonbuk National University, Jeonju, Republic of Korea.
authors.forename: Kwang-Pyo
authors.initials: KP
authors.lastname: Kim
authors.affiliation: Department of Food and Animal Biotechnology, School of Agricultural Biotechnology, Center for Food and Bioconvergence, and Research Institute for Agricultural and Life Science, Seoul National University, San 56-1, Sillim-dong, Kwanak-gu, Seoul 151-742, Republic of Korea; Department of Food Science and Technology, College of Agriculture and Life Sciences, Chonbuk National University, Jeonju, Republic of Korea.
authors.forename: Sangryeol
authors.initials: S
authors.lastname: Ryu
authors.affiliation: Department of Food and Animal Biotechnology, School of Agricultural Biotechnology, Center for Food and Bioconvergence, and Research Institute for Agricultural and Life Science, Seoul National University, San 56-1, Sillim-dong, Kwanak-gu, Seoul 151-742, Republic of Korea; Department of Food Science and Technology, College of Agriculture and Life Sciences, Chonbuk National University, Jeonju, Republic of Korea. Electronic address: kang7820@snu.ac.kr.
authors.forename: Dong-Hyun
authors.initials: DH
authors.lastname: Kang
mesh_terms: D001628:Beverages / Q000382:microbiology*; D019453:Escherichia coli O157 / Q000187:drug effects / Q000502:physiology; D005511:Food Handling / Q000379:methods* / Q000592:standards; D005516:Food Microbiology; D006358:Hot Temperature; D008089:Listeria monocytogenes / Q000187:drug effects / Q000502:physiology; D027845:Malus / Q000382:microbiology; D010083:Oxidants, Photochemical / Q000494:pharmacology; D010126:Ozone / Q000494:pharmacology*; D012486:Salmonella typhimurium / Q000187:drug effects / Q000502:physiology
chemical_list: D010083:Oxidants, Photochemical; D010126:Ozone
keywords: Apple juice; Food safety; Foodborne pathogens; Ozone treatment; Temperature