Department of Food Engineering, Faculty of Engineering, University of Gaziantep, Gaziantep, Turkey.
Foodborne Pathog Dis. 2010 Aug;7(8):953-8. doi: 10.1089/fpd.2009.0509.
In this study, the antimicrobial effects of hypochlorite (HOCl) on Escherichia coli in tap water were investigated. The effects of 0.1% thyme oil and 100 mg/L HOCl on E. coli on vegetables (lettuce, parsley leafs, and red pepper) were also studied. E. coli was reduced by 2.54, 3.33, 3.93, 4.87, and 5.57 log colony forming units (cfu)/mL with 0.25, 0.5, 1.0, 10, and 50 mg/mL HOCl, respectively. There was an increase of more than 30% in the inactivation of E. coli with 10 degrees C rise in temperature, a remarkable increase in antimicrobial activity at pH 5.0 was also observed with 5.62 log cfu/mL reductions in 30 sec, as well as marked neutralization of the effect in the presence of 0.1% peptone in water was noted. Biphasic kinetics in the inactivation curves of E. coli was observed. HOCl, thyme oil, and their mixture reduced the number of E. coli between 1.23 and 3.75 log cfu/mL after 5-min exposure on vegetables. The degree of E. coli inactivation depends on concentration of residual chlorine, suspending medium, type of vegetables, and the use of thyme essential oil.
在这项研究中，研究了次氯酸钠（HOCl）对自来水中大肠杆菌的抗菌作用。还研究了 0.1%百里香精油和 100mg/L HOCl 对蔬菜（生菜、欧芹叶和红辣椒）上大肠杆菌的影响。大肠杆菌分别用 0.25、0.5、1.0、10 和 50mg/mL 的 HOCl 处理后，减少了 2.54、3.33、3.93、4.87 和 5.57 对数菌落形成单位（cfu）/mL。温度升高 10°C，大肠杆菌的失活率增加了 30%以上，在 pH 值为 5.0 时抗菌活性显著增加，在 30 秒内减少了 5.62 对数 cfu/mL，在水中存在 0.1%蛋白胨时，效果明显中和。大肠杆菌失活曲线呈两相动力学。HOCl、百里香精油及其混合物在 5 分钟的暴露时间内可使蔬菜上的大肠杆菌数量减少 1.23 至 3.75 对数 cfu/mL。大肠杆菌的失活程度取决于余氯浓度、悬浮介质、蔬菜类型和使用百里香精油。
