In-package atmospheric cold plasma treatment of bulk grape tomatoes for microbiological safety and preservation

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>Effects of dielectric barrier discharge atmospheric cold plasma (DACP) treatment on the inactivation of <I>Salmonella</I> and the storability of grape tomato were investigated. Grape tomatoes, with or without inoculation with <I>Salmonella</I>, were packaged in a polyethylene terephthalate (PET) commercial clamshell container and cold plasma-treated at 35 kV at 1.1 A for 3 min using a DACP system equipped with a pin-type high-voltage electrode. DACP treatment inactivated <I>Salmonella</I> (<I>p</I> < 0.05) without altering the color or firmness of the grape tomatoes (<I>p</I> > 0.05). DACP treatment inactivated <I>Salmonella</I> uniformly in both layers of the double-layer configuration of the grape tomatoes regardless of the position of the tomatoes in each layer. <I>Salmonella</I> was most efficiently inactivated when the headspace to tomato volume ratio of the container was highest. Integration of rolling of tomatoes during treatment significantly increased the <I>Salmonella</I> reduction rates from 0.9 ± 0.2 log CFU/tomato to 3.3 ± 0.5 log CFU/tomato in the double-layer configuration of the tomato samples. Rolling-integrated DACP also initially reduced the number of total mesophilic aerobic bacteria and yeast and molds in the double-layer configuration of tomato samples by 1.3 ± 0.3 and 1.5 ± 0.2 log CFU/tomato, respectively. DACP treatment effectively reduced the growth of <I>Salmonella</I> and indigenous microorganisms at 10 and 25 °C, and did not influence the surface color, firmness, weight loss, lycopene concentration and residual ascorbic acid of grape tomatoes during storage at 10 and 25 °C. DACP treatment holds promise as a post-packaging process for improving microbial safety against <I>Salmonella</I> and storability of fresh grape tomatoes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Atmospheric cold plasma treatment (ACPT) inactivates <I>Salmonella</I> on grape tomatoes. </LI> <LI> A higher container headspace to tomato volume ratio results in higher inactivation. </LI> <LI> Inactivation is uniform with tomatoes in a 2-layer configuration in the container. </LI> <LI> Rolling of samples during ACPT increases <I>Salmonella</I> reduction rates. </LI> <LI> ACPT inhibits microbial growth during storage without affecting quality. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>