Destruction of Escherichia coli O157:H7 on whole apples via single and sequential application of chemical sanitizers

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dc.contributor.author Traynham, Toshiba
dc.contributor.department Food Technology
dc.date 2020-08-05T05:04:52.000
dc.date.accessioned 2021-02-26T08:44:57Z
dc.date.available 2021-02-26T08:44:57Z
dc.date.copyright Wed Jan 01 00:00:00 UTC 2003
dc.date.issued 2003-01-01
dc.description.abstract <p>This study was conducted to determine if single and sequential application of selected chemical sanitizers can achieve a 5-log reduction in Escherichia coli O157:H7 populations on apple surfaces. Sanitizers were utilized with and without mild heat to determine if increased temperatures would have an effect on sanitizer efficacy. Apples were spot-inoculated with a non-pathogenic strain of E. coli O157:H7, immersed in a sanitizer for 2 min and rinsed in distilled water for 5 sec. Chemical sanitizers used for single application were chlorine (200 ppm), hydrogen peroxide (5%), sodium bicarbonate buffer (pH 11.5), 1.5% H2O2 + 1.5% lactic acid, Tsunami100[superscript trademark symbol] (80 ppm) and ProSan[superscript trademark symbol] (1%). Among these chemical sanitizers, chlorine, 5% hydrogen peroxide, 1.5% hydrogen peroxide + 1.5% lactic acid, sodium bicarbonate buffer and Pro-San[superscript trademark symbol] were used sequentially on apple surfaces for 2 min per sanitizer. Bacterial populations were enumerated by duplicate plating on Tryptic Soy agar (TSA) and Sorbitol MacConkey agar (SMA) after 24 or 48 hr incubation at 35 or 370C. Populations of E. coli O157:H7 on apples immersed in (single) chemical sanitizers at 250C were reduced by 1.35 to 3.07 log10CFU/apple (TSA) and 1.82 to 3.77 log10CFU/apple (SMA). Log10 reductions for single treatments applied at 550C were 1.46 to 3.72 log10CFU/apple (TSA) and 2.31 to 3.90 log10CFU/apple (SMA). Sequential treatments at 250C eliminated E. coli O157:H7 by 2.10 to 3.17 log cycles based on TSA counts and 1.47 to 3.01 log cycles based on SMA counts. At 550C, E. coli O157:H7 populations were eliminated by 2.59 to 3.54 log cycles (TSA) and 1.96 to 3.27 log cycles (SMA). Single application of 1.5% hydrogen peroxide + 1.5% lactic acid and sequential application of chlorine (200 ppm) and 1.5% hydrogen peroxide + 1.5% lactic acid at 550C achieved the highest reductions of E. coli O157:H7 populations on apple surfaces at 3.90 and 3.27 log cycles (SMA), respectively. Results suggest that single and sequential application of chemical sanitizers were not effective in achieving a 5-log reduction of E. coli O157:H7 on whole apples based on conditions of the present study but can reduce the populations of the pathogen by approximately 4-log.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/rtd/20068/
dc.identifier.articleid 21067
dc.identifier.contextkey 18791862
dc.identifier.doi https://doi.org/10.31274/rtd-20200803-391
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath rtd/20068
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/97435
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/rtd/20068/Traynham_ISU_2003_T73.pdf|||Fri Jan 14 22:19:24 UTC 2022
dc.subject.keywords Food science and human nutrition
dc.subject.keywords Food science and technology
dc.title Destruction of Escherichia coli O157:H7 on whole apples via single and sequential application of chemical sanitizers
dc.type article
dc.type.genre thesis
dspace.entity.type Publication
thesis.degree.discipline Food Science and Technology
thesis.degree.level thesis
thesis.degree.name Master of Science
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