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United States Department of Agriculture

Agricultural Research Service

Title: Efficacy of Different Washing Agents in Reducing the Populations of Escherichia Coli 0157:h7 on Artificially Inoculated Golden Delicious Apples

item Annous, Bassam
item Burke, Angela

Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: October 12, 2001
Publication Date: October 12, 2001
Citation: Annous, B.A., Burke, A.M. 2001. Efficacy of different washing agents in reducing the populations of escherichia coli 0157:h7 on artificially inoculated golden delicious apples. Meeting Abstract, Proceedings of the United States - Japan, 30th Annual Meeting, Tsukuba, Ibaraki,p.86-92.

Technical Abstract: Conventional and experimental washing formulations were applied at 20 and 60 degrees Celsius(C) to determine their efficacy in decontaminating apples inoculated with Escherichia coli O157:H7. Treated and untreated whole and dissected apple samples were analyzed for residual E. coli O157:H7. E. coli O157:H7 populations were mainly attached to the calyx and stem regions scompared to the outer skin of the apple. E. coli O157:H7 was able to infiltrate the core of the apple, mainly through the calyx region. Apples were washed in a covered glass tank containing one of the following washing solutions (4 liters): tap water, 5% hydrogen peroxide, 1200 ppm Sanova (acidified sodium chlorite), 850 ppm Sanova, 500 ppm Sanova, 850 ppm Sanova basic, 850 ppm Sanova acidic, 400 and 200 ppm chlorine (pH=8.8), and 400 and 200 ppm chlorine (pH=6.5). None of the washing treatments used under these experimental conditions was able to completely inactivate or remove E. coli O157:H7 populations on the inoculated apples. This could be as a consequence of the inability of this washing system to inactivate or remove the bacterial cells in inaccessible calyx, stem and core regions of the apple. Washing at 60C resulted in higher log reduction of pathogen populations when compared to washing at 20C. These results are important because they demonstrate the need for new fruit washing technologies that can overcome the inability to decontaminate the calyx and stem regions of apples.

Last Modified: 5/5/2015
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