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The effects of surface coating, microbial loading, surface-to-volume ratio, sample stacking, mixing of samples with romaine lettuce, and shaking of the samples on the inactivation of Salmonella contaminating boiled chicken breast (BCB) cubes using in-package atmospheric dielectric barrier discharge cold plasma (ADCP) treatment at 38.7 kV were investigated. Whey protein coating increased the ADCP treatment efficacy in inactivating Salmonella on BCB cubes; the D-value increased from 0.2 to 1.3 min when the initial inoculum concentration increased from 3.8 to 5.7 log CFU/sample. ADCP decontaminated stacked BCB samples uniformly, and shaking during the treatment increased the inactivation rate. The concentrations of chicken protein isolate, water, and soybean oil in a chicken breast model food that resulted in the highest Salmonella reduction (1.7 log CFU/sample) were 20.5%, 68.9%, and 10.6%, respectively. ADCP treatment did not affect the color and tenderness of the model food, irrespective of its composition. The present study indicated that ADCP is a feasible technology to decontaminate prepackaged ready-to-eat meat cube products., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Effects of dielectric barrier discharge atmospheric cold plasma (DACP) treatment on the inactivation of Salmonella and the storability of grape tomato were investigated. Grape tomatoes, with or without inoculation with Salmonella, 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 Salmonella (p < 0.05) without altering the color or firmness of the grape tomatoes (p > 0.05). DACP treatment inactivated Salmonella uniformly in both layers of the double-layer configuration of the grape tomatoes regardless of the position of the tomatoes in each layer. Salmonella 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 Salmonella 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 Salmonella 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 Salmonella and storability of fresh grape tomatoes., (Published by Elsevier Ltd.)

The present study investigated the effects of dielectric barrier discharge atmospheric cold plasma (DACP) treatment on the inactivation of Escherichia coli O157:H7, Salmonella, Listeria monocytogenes, and Tulane virus (TV) on Romaine lettuce, assessing the influences of moisture vaporization, modified atmospheric packaging (MAP), and post-treatment storage on the inactivation of these pathogens. Romaine lettuce was inoculated with E. coli O157:H7, Salmonella, L. monocytogenes (~6logCFU/g lettuce), or TV (~2logPFU/g lettuce) and packaged in either a Petri dish (diameter: 150mm, height: 15mm) or a Nylon/polyethylene pouch (152×254mm) with and without moisture vaporization. Additionally, a subset of pouch-packaged leaves was flushed with O 2 at 5% or 10% (balance N 2 ). All of the packaged lettuce samples were treated with DACP at 34.8kV for 5min and then analyzed either immediately or following post-treatment storage for 24h at 4°C to assess the inhibition of microorganisms. DACP treatment inhibited E. coli O157:H7, Salmonella, L. monocytogenes, and TV by 1.1±0.4, 0.4±0.3, 1.0±0.5logCFU/g, and 1.3±0.1logPFU/g, respectively, without environmental modifications of moisture or gas in the packages. The inhibition of the bacteria was not significantly affected by packaging type or moisture vaporization (p>0.05) but a reduced-oxygen MAP gas composition attenuated the inhibition rates of E. coli O157:H7 and TV. L. monocytogenes continued to decline by an additional 0.6logCFU/g in post-treatment cold storage for 24h. Additionally, both rigid and flexible conventional plastic packages appear to be suitable for the in-package decontamination of lettuce with DACP., (Published by Elsevier B.V.)

Microwave-powered cold plasma treatment (CPT) has been investigated as a nonthermal intervention technology for improving the microbiological safety of cherry tomatoes ( Solanum lycopersicum var. cerasiforme ) against Salmonella (approximately 7 log CFU/tomato). Cherry tomatoes were subjected to CPT using helium (He) or a He-oxygen (O 2 ) gas mixture for 2–10 min at 400–900 W of plasma generation power. A central composite method was applied to investigate the interactions between treatment conditions and the Salmonella reduction rate, weight loss, or temperature of the tomatoes. CPTs using He and a He-O 2 gas mixture at 827 W for 9 min resulted in the greatest reduction in Salmonella numbers (3.5 ± 0.1 and 3.5 ± 0.5 log CFU/tomato, respectively) and temperature increases of 3.0 ± 0.3 and 3.5 ± 0.4 °C, respectively. He-CPT at 900 W for 10 min, determined as the optimal conditions for Salmonella inactivation in this study, did not appreciably influence the surface morphology of cherry tomatoes. While the optimal He-CPT did not effectively inhibit the growth of Salmonella on the tomatoes at 25 °C, the treatment prevented the Salmonella growth during storage at 5 °C, without affecting the tomato respiration rate ( P < 0.05). These results demonstrate the potential of CPT as a postharvest technology to improve the microbiological safety of cherry tomatoes against Salmonella , without affecting their biological properties. [ABSTRACT FROM AUTHOR]

Highlights: [•] The first report on agricultural byproduct-based edible film formation by pressing. [•] Defatted soybean meal (DSM)-based edible films were developed using heat pressing. [•] Films can be formulated to obtain the desired tensile and moisture barrier properties. [•] Antimicrobial DSM films were developed by incorporating the lactoperoxidase system. [•] Temperature and aw of coated food affected antimicrobial diffusion in the coating. [ABSTRACT FROM AUTHOR]

Abstract: Antimicrobial films were developed using defatted soybean meal (DSM), a by-product left after crushing soybeans for oil, and the lactoperoxidase system (LPOS). Effects of the composition of the films on physical and antimicrobial properties of the films and the diffusion of antimicrobial hypothiocyanite (OSCN−) from the LPOS in the films were investigated. The antimicrobial DSM film inhibited Salmonella (4 log CFU/cm2) on agar media. Yellowness and elongation of the film increased, while lightness and the elastic modulus decreased as the concentration of protein increased in the film. The composition of the films did not affect their antimicrobial activity. The diffusion of antimicrobial OSCN− in the film increased with increasing concentrations of glycerol or protein in the film, storage temperature, or water activity of the food on which the film was applied, and thus the film can be formulated to achieve a necessary antimicrobial release rate. The composition of the DSM can be used to predict the physical and diffusion properties of the DSM-based antimicrobial films prepared from different DSMs. The DSM film coating did not significantly affect the sensory properties of sliced ham (P > 0.05), demonstrating the potential for the application to commercial ham products. [Copyright &y& Elsevier]

An in-package cold plasma (CP) treatment integrated with hydrogen peroxide (H 2 O 2) treatment was developed for the inactivation of foodborne pathogens in cabbage slices packaged in polyethylene terephthalate (PET) containers. The effects of H 2 O 2 -CP treatment on microbial inactivation, microbial cell membrane integrity, cell oxidation, and the antioxidant activity and color of cabbage slices were investigated. As the treatment time increased from 1 to 2 and 3 min, the respective reduction level of Salmonella increased from 0.6 to 0.9 log CFU/g (p < 0.05). Moreover, the levels of Salmonella reduction were 0.8, 0.9, 1.8, and 1.5 log CFU/g when the H 2 O 2 concentrations in the H 2 O 2 pad within the package were 3, 10, 20, and 30%, respectively. The values for cell lipid peroxidation, reactive oxygen species generation, and number of non-viable cells with damaged membranes, increased following CP and H 2 O 2 -CP treatments. Meanwhile, H 2 O 2 -CP treatment did not influence the antioxidant activities nor the color of cabbage slices. However, the concentration of malondialdehyde in cabbage slices was increased by H 2 O 2 -CP treatment. The results suggest that H 2 O 2 -CP treatment is an effective strategy for disinfecting cabbage slices without altering their antioxidant activities and color. • In-package cold plasma (CP) and H 2 O 2 treatment inactivates Salmonella effectively. • Increased treatment time enhances reduction of Salmonella in cabbage slices. • H 2 O 2 decreases the number of Salmonella in a concentration dependent manner. • CP/H 2 O 2 -CP treatments increase lipid peroxidation, ROS, and non-viable cell number. • H 2 O 2 -CP treatment does not impact antioxidant activities or color of cabbage slices. [ABSTRACT FROM AUTHOR]

Abstract Effects of packaging parameters on the inactivation of Salmonella contaminating mixed vegetables in plastic packages using atmospheric dielectric barrier discharge cold plasma treatment (ADCPT) were investigated. The inactivation rate of indigenous aerobes of grape tomatoes in low density polyethylene packaging (1.2 log CFU/tomato) was higher than that in polyethylene terephthalate packaging (0.8 log CFU/tomato). Increasing oxygen concentration in the package headspace by 85% did not affect the Salmonella reduction rate. However, an increase in the volume ratio of headspace to sample from 30:1 to 43:1, a change from indirect treatment to direct treatment, and the use of secondary packaging led to an increase in the Salmonella reduction rates by 1.2, 2.3, and 0.7 log CFU/tomato, respectively. The water vapor permeability of the tested packages increased after ADCPT by 16.7–41.7%, while tensile properties, transparency, glass transition temperature, and surface morphology did not change. Differences in inactivation effects according to package shape were eliminated by shaking during treatment. The results demonstrated the packaging parameter-dependent efficacy of in-package ADCPT and effective ADCPT for mixed vegetable decontamination with minimal package property modification. Highlights • Atmospheric cold plasma (ACP) decontaminates mixed vegetables in plastic containers. • Effective container parameters include the kinds of plastics and package shape. • Effective treatment parameters are container shaking and sample–electrode distance. • Other key parameters are secondary packaging and headspace-sample volume ratio. [ABSTRACT FROM AUTHOR]

This study investigated the effects of cold plasma treatment (CPT) on the inhibition of Salmonella typhimurium on radish sprouts and the quality attributes of the sprouts. Radish sprouts were treated with nitrogen (N 2 )-cold plasma at 900 W and 667 Pa for 0, 2, 5, 10, and 20 min using a microwave-powered CPT system. The sensory attributes of the radish sprouts, appearance and odor, were evaluated before and after the treatment. The effects of N 2 -CPT for 10 min on microbial growth and the quality attributes of the radish sprouts were evaluated during storage for 12 days at 4 and 10 °C. N 2 -CPT at 900 W and 667 Pa for 20 min reduced the number of S . typhimurium by 2.6 ± 0.4 log CFU/g. The moisture content of the radish sprouts decreased with treatment time. The appearance and odor of the radish sprouts were not altered by CPT ( p > 0.05) and this treatment did not affect the quality attributes of the sprouts in terms of color, ascorbic acid concentration, or antioxidant activity during storage at both 4 and 10 °C. These findings suggest that CPT has the potential to improve the microbiological safety of radish sprouts with reference to S . typhimurium during cold storage without significant detriment to its quality properties. [ABSTRACT FROM AUTHOR]

Effects of in-package atmospheric dielectric barrier discharge cold plasma (CP) treatment on the antimicrobial efficacy of malic acid-incorporated whey protein isolate (MA–WPI) coating and MA diffusion in MA–WPI-coated skinless chicken breast processed meat (CBPM) were evaluated. MA–WPI coating followed by CP treatment (MA–WPI + CP) inactivated Salmonella (5.6 log CFU/g) in CBPM by 1.8 log CFU/g. CP treatment increased Salmonella reduction rates in MA–WPI-coated samples during storage at 4 and 10 °C and the diffusion coefficients of MA in the coating, which was confirmed by comparing results of MA–WPI + CP-treated and MA–WPI-coated samples. CP treatment facilitates MA diffusion in the coating, thereby increasing the Salmonella inhibition efficacy of the coating. MA–WPI + CP treatment did not influence the color and lipid oxidation of CBPM during storage at 4 °C and the water vapor permeability, elongation, and elastic modulus of MA–WPI films. Through the technological development of in-package cold plasma treatment for decontamination of food in the industrial production line, the microbiological safety of ready-to-eat foods coated with antimicrobials can be effectively increased by exposing the coated foods to cold plasma to accelerate the diffusion of the antimicrobials in the coating to the site of microbial contamination at the surface. The effect of cold plasma treatment on the antimicrobial efficacy of the antimicrobial coating is useful, especially during the initial stages when the coating is expected to exhibit highly efficacious antimicrobial function. • CC inactivated Salmonella in processed chicken meat (PCM) by 1.8 log CFU/g, Cold plasma treatment (CP) after antimicrobial edible coating (CC) was investigated • CP enhanced the Salmonella -inactivation efficacy of the coating by 0.7 log CFU/g • CP increased the malic acid diffusion rate in whey protein coating by 2.1–2.5 times • CP did not change the acid's diffusion phenomena in PCM and the film/PCM interface [ABSTRACT FROM AUTHOR]

An intervention technology combining in-package atmospheric discharge cold plasma (CP) treatment with ultraviolet (UV)-activated zinc oxide (ZnO) treatment was developed to decontaminate steamed fish cakes in commercial plastic packages. Efficacy of the simultaneous treatment of UV-activated ZnO treatment and CP treatment (ZnO&CP treatment) in inactivating Salmonella (1.8 log CFU/g) did not differ significantly from that of the CP-only treatment (P > 0.05). The CP treatment immediately after UV-activated ZnO treatment (ZnO-CP treatment) led to higher inactivation of Salmonella (2.4 log CFU/g) than the ZnO-only (0.4 log CFU/g) or CP-only (1.7 log CFU/g) treatments. Inactivation of Salmonella by ZnO-CP treatment increased as the ZnO or CP treatment time increased, the number of samples in the package decreased, and upon shaking the package during the CP treatment. The difference in Salmonella counts between ZnO-CP treated and untreated samples were maintained at 1.3–1.8 log CFU/g and 1.1–1.6 log CFU/g when samples were stored at 4 °C and 10 °C for 21 days, respectively. The ZnO-CP treatment did not alter the moisture content, water activity, color, pH, and gel strength of the steamed fish cake at both storage temperatures. However, the ZnO-CP treatment reduced the total volatile base nitrogen content in the steamed fish cake stored at 10 °C. These results demonstrated the potential of applying a combined treatment approach for microbial decontamination of steamed fish cake in plastic packages. • In-package combined cold plasma and zinc oxide (ZnO-CP) treatment was developed • ZnO-CP treatment effectively inhibits Salmonella in ready-to-eat steamed fish cake • ZnO-CP treatment demonstrates an additional effect in microbial inactivation • Treatment time, fish cake number, and package shaking affect microbial inactivation • ZnO-CP treatment does not alter the quality properties of steamed fish cake [ABSTRACT FROM AUTHOR]

A nonthermal process that applies ultraviolet (UV)–C and helium cold plasma (CP) simultaneously (UV-CP) has been investigated as an intervention technology to inactivate Salmonella on black peppercorns. The optimum CP treatment voltage and UV-CP treatment time for inactivating Salmonella on black peppercorns were predicted using a model equation as 9.7 kV and 22.1 min, respectively, which non-thermally inactivated Salmonella by 3.7 log CFU/g. UV-CP treatment yielded a stronger bactericidal activity than UV treatment alone, without inducing photoreactivation. In addition, UV-CP-induced reactive species were similar to those found in individual UV and CP treatments. Furthermore, UV-CP treatment caused a profound deformation of Salmonella morphology and a greater extent of DNA damage than UV or CP treatment did alone. UV-CP treatment did not alter the color or 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity; however, it lowered the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and piperine concentration in the peppercorns. The findings of this study demonstrate the potential application of UV-CP treatment for decontamination of black peppercorns. • UV-cold plasma (CP) treatment effectively inhibits Salmonella in black peppercorns. • The polynomial model adequately predicts Salmonella inactivation by UV-CP • UV-CP treatment does not induce photoreactivation of Salmonella in the peppercorns. • UV-CP treatment disintegrates the cellular structure and damages Salmonella DNA. • UV-CP treatment is non-thermal and does not alter the color of black peppercorns. [ABSTRACT FROM AUTHOR]

This study investigated the efficacy of atmospheric dielectric barrier discharge in-package cold plasma treatment (ADCPT) in inactivating Escherichia coli O157:H7, Salmonella , Listeria monocytogenes , and Tulane virus (TV) in whey protein-coated boiled chicken breast (BCB) cubes. The optimal ADCPT conditions for Salmonella inactivation were determined, and the effects of ADCPT on lipid oxidation and color were also evaluated. The optimal ADCPT voltage and time for Salmonella inactivation were found to be 39 kV and 3.5 min, respectively, resulting in a reduction of 3.7 log CFU/cube. Further, these conditions effectively inactivated E. coli O157:H7 (3.9 log CFU/cube), L. monocytogenes (3.5 log CFU/cube), and TV (2.2 PFU/cube). A second-order polynomial model can be used to explain the inactivation of Salmonella. ADCPT did not significantly affect the values of thiobarbituric acid reactive substance or color of BCB. Thus, these results suggest that ADCPT is an effective method for enhancing the microbiological safety of ready-to-eat packaged BCB by inactivating major foodborne pathogens and human norovirus without affecting the lipid oxidation and color of BCB. Image 1 • Cold plasma (CP) effectively inactivates the foodborne pathogens on chicken samples. • In-package CP effectively inactivates Tulane virus, a human norovirus surrogate. • CP effectively decontaminates chicken samples in commercial plastic containers. • Microbial inactivation data are explained by the investigated mathematical models. • CP does not affect the sample's color, lipid oxidation, and protein degradation. [ABSTRACT FROM AUTHOR]