AUTHOR=Kilonzo-Nthenge Agnes , Liu Siqin , Yannam Sudheer , Patras Ankit 

TITLE=Atmospheric Cold Plasma Inactivation of Salmonella and Escherichia coli on the Surface of Golden Delicious Apples

JOURNAL=Frontiers in Nutrition

VOLUME=5

YEAR=2018

URL=https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2018.00120

DOI=10.3389/fnut.2018.00120

ISSN=2296-861X

ABSTRACT=<p>The contamination of fruits with human pathogens is a reoccurring concern in the fresh produce industry. Atmospheric cold plasma (ACP) is a potential alternate to customary approaches for non-thermal decontamination of foods. In this study, the efficacy of a dielectric barrier discharge ACP system against <italic>Salmonella</italic> (<italic>Salmonella</italic> Typhimurium, ATCC 13311; <italic>Salmonella</italic> Choleraesuis, ATCC 10708) and <italic>Escherichia coli</italic> (ATCC 25922, ATCC 11775) was explored. For each bacteria, a two-strain mixture at 8 log<sub>10</sub> CFU/ml was spot inoculated on the surface of Golden Delicious apples, air dried, and exposed to ACP at a fixed distance of 35 mm, input power of 200 W for 30, 60, 120, 180, and 240 s. Bacterial inactivation was achieved in all treatment times with highest reduction of 5.3 log<sub>10</sub> CFU/cm<sup>2</sup> for <italic>Salmonella</italic> and 5.5 log<sub>10</sub> CFU/cm<sup>2</sup> for <italic>E. coli</italic>. Our results showed that reductions were interrelated to exposure time and ranged from 1.3 to 5.3 and 0.6 to 5.5 log<sub>10</sub> CFU/cm<sup>2</sup> for <italic>Salmonella</italic> and <italic>E. coli</italic>, respectively. <italic>Salmonella</italic> and <italic>E. coli</italic> significantly decreased (&gt;5.0 log) at 180 and 240 s as compared to 30, 60, and 120 s exposure. Microbial inactivation data was modeled by using Weibull distribution. These findings demonstrate the potential of ACP as a postharvest technology to effectively reduce pathogens on apples, with reference to <italic>Salmonella</italic> and <italic>E. coli</italic>.</p>