Beuchat L R, Harris L J, Ward T E, Kajs T M
Center for Food Safety and Department of Food Science and Technology, University of Georgia, Griffin 30223-1797, USA.
J Food Prot. 2001 Aug;64(8):1103-9. doi: 10.4315/0362-028x-64.8.1103.
A series of studies was done for the purpose of developing a proposed standard method to evaluate point-of-use home sanitizers for fresh produce. Preliminary experiments were done to determine the survival of Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes after inoculation onto the surface of ripe tomatoes and drying for up to 24 h at 22 +/- 2 degrees C. Within 2 h, the initial population (6.88 log10 CFU/tomato) of E. coli O157:H7 was reduced by approximately 3 log10, while reductions in similar initial populations of Salmonella and L. monocytogenes were approximately 1 and 0.6 log10 CFU/tomato, respectively, after 40 min and 3 h. A pilot study evaluated treatment with 200 ppm free chlorine and a prototype Fit produce wash (Fit) for their efficacy in killing a five-serotype mixture of Salmonella or L. monocytogenes spot inoculated on tomatoes using the proposed inoculation and recovery procedures. Inoculated tomatoes were sprayed with chlorinated water, Fit, or sterile distilled water (control) and hand rubbed for 30 s. Each tomato was then placed in a plastic bag and rinsed with 200 ml of sterile water by vigorously agitating for 30 s to simulate a procedure consumers might use for sanitizing and rinsing produce in a home setting. Each tomato was transferred to a second bag, and 20 ml of sterile 0.1% peptone was added; tomatoes were rubbed by hand for 40 s. Populations of Salmonella or L. monocytogenes in the rinse water and the 0.1% peptone wash solution were determined. Treatment with 200 ppm chlorine and Fit resulted in > or = 3.07 and > 6.83 log10 reductions, respectively, in Salmonella. Treatment with 200 ppm chlorine and Fit reduced the number of L. monocytogenes by > or = 3.33 and > or = 4.96 log10 CFU/tomato, respectively. The proposed standard method for testing the efficacy of point-of-use produce sanitizers needs to be evaluated for reproducibility of results through a larger scale series of experiments.
为了制定一种评估新鲜农产品家用即用型消毒剂的标准方法，开展了一系列研究。进行了初步实验，以确定将大肠杆菌O157:H7、沙门氏菌和单核细胞增生李斯特菌接种到成熟番茄表面，并在22±2℃下干燥长达24小时后的存活情况。在2小时内，大肠杆菌O157:H7的初始菌量（6.88 log10 CFU/番茄）减少了约3 log10，而沙门氏菌和单核细胞增生李斯特菌类似初始菌量在40分钟和3小时后分别减少了约1 log10 CFU/番茄和0.6 log10 CFU/番茄。一项初步研究评估了用200 ppm游离氯和一种原型Fit农产品清洗液（Fit）处理接种在番茄上的五种血清型沙门氏菌或单核细胞增生李斯特菌混合物的杀菌效果，采用了建议的接种和回收程序。对接种的番茄喷洒氯水、Fit或无菌蒸馏水（对照），并手工揉搓30秒。然后将每个番茄放入塑料袋中，通过剧烈搅拌30秒用200毫升无菌水冲洗，以模拟消费者在家中对农产品进行消毒和冲洗的程序。将每个番茄转移到另一个袋子中，加入20毫升无菌0.1%蛋白胨；手工揉搓番茄40秒。测定冲洗水和0.1%蛋白胨洗涤液中沙门氏菌或单核细胞增生李斯特菌的菌量。用200 ppm氯和Fit处理分别使沙门氏菌减少≥3.07 log10和>6.83 log10。用200 ppm氯和Fit处理分别使单核细胞增生李斯特菌的菌量减少≥3.33 log10 CFU/番茄和≥4.96 log10 CFU/番茄。需要通过更大规模的一系列实验来评估所提议的测试家用农产品消毒剂效果的标准方法结果的可重复性。
