Department of Food and Animal Biotechnology, School of Agricultural Biotechnology, Seoul National University, San 56-1, Sillim-dong, Kwanak-gu, Seoul 151-742, Korea.
J Food Prot. 2011 Jun;74(6):899-904. doi: 10.4315/0362-028X.JFP-10-552.
The effects of ohmic heating on reduction of Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes in orange and tomato juice were investigated. Orange and tomato juice inoculated with E. coli O157:H7, Salmonella Typhimurium, and L. monocytogenes were subjected to ohmic heating with selected parameters including electric field strength from 10 to 20 V/cm and treatment times from 0 to 540 s. The number of pathogens was reduced by increasing the electric field strength from 10 to 20 V/cm as well as increasing treatment time. The population of E. coli O157:H7 was reduced more than 5 log after 120, 210, and 540 s of treatment in orange juice with 20, 15, and 10 V/cm electric field strengths, respectively. In tomato juice, levels of E. coli O157:H7 were reduced more than 5 log after 90, 180, and 480 s with the same electric field strengths. Similar phenomena were observed for Salmonella Typhimurium and L. monocytogenes, but E. coli O157:H7 was the most resistant to ohmic heating treatment. These results show that ohmic heating is potentially useful for inactivation of E. coli O157:H7, Salmonella Typhimurium, and L. monocytogenes and that the effect of inactivation depends on applied electric field strength, treatment time, pathogen species, and type of juice.
研究了欧姆加热对橙汁和番茄汁中大肠杆菌 O157:H7、鼠伤寒沙门氏菌和单增李斯特菌减少的影响。将接种了大肠杆菌 O157:H7、鼠伤寒沙门氏菌和单增李斯特菌的橙汁和番茄汁用选定的参数进行欧姆加热，包括电场强度为 10 到 20 V/cm 和处理时间为 0 到 540 s。通过增加电场强度从 10 到 20 V/cm 以及增加处理时间，可以减少病原体的数量。在 20、15 和 10 V/cm 电场强度的橙汁中，经过 120、210 和 540 s 的处理，大肠杆菌 O157:H7 的数量减少了 5 个对数级以上。在番茄汁中，大肠杆菌 O157:H7 的水平在相同的电场强度下分别经过 90、180 和 480 s 的处理后减少了 5 个对数级以上。沙门氏菌和单增李斯特菌也观察到类似的现象，但大肠杆菌 O157:H7 对欧姆加热处理的抵抗力最强。这些结果表明，欧姆加热在减少大肠杆菌 O157:H7、鼠伤寒沙门氏菌和单增李斯特菌方面具有潜在的应用价值，其灭活效果取决于应用的电场强度、处理时间、病原体种类和果汁类型。
