Effect of in‐package atmospheric cold plasma discharge on microbial safety and quality of ready‐to‐eat ham in modified atmospheric packaging during storage

Abstract

Listeria monocytogenes is often responsible for postprocessing contamination of ready-to-eat (RTE) products including cooked ham. As an emerging technology, atmospheric cold plasma (ACP) has the potential to inactivate L. monocytogenes in packaged RTE meats. The objectives of this study were to evaluate the effect of treatment time, modified atmosphere gas compositions (MAP), ham formulation, and post-treatment storage (1 and 7 days at 4°C) on the reduction of a five-strain cocktail of L. monocytogenes and quality changes in ham subjected to in-package ACP treatment. Initial average cells population on ham surfaces were 8 log CFU/cm 2 . The ACP treatment time and gas composition significantly (P < 0.05) influenced the inactivation of L. monocytogenes, irrespective of ham formulations. When MAP1 (20% O 2 + 40% CO 2 + 40% N 2 ) was used, there was a significantly higher log reduction (>2 log reduction) in L. monocytogenes on ham in comparison to MAP2 (50% CO 2 + 50% N 2 ) and MAP3 (100% CO 2 ), irrespective of ham formulation. Addition of preservatives (that is, 0.1% sodium diacetate and 1.4% sodium lactate) or bacteriocins (that is, 0.05% of a partially purified culture ferment from Carnobacterium maltaromaticum UAL 307) did not significantly reduce cell counts of L. monocytogenes after ACP treatment. Regardless of type of ham, storage of 24 hr after ACP treatment significantly reduced cells counts of L. monocytogenes to approximately 4 log CFU/cm 2 . Following 7 days of storage after ACP treatment, L. monocytogenes counts were below the detection limit (>6 log reduction) when samples were stored in MAP1. However, there were significant changes in lipid oxidation and color after post-treatment storage. In conclusion, the antimicrobial efficacy of ACP is strongly influenced by gas composition inside the package and post-treatment storage.Practical Application: Surface contamination of RTE ham with L. monocytogenes may occur during processing steps such as slicing and packaging. In-package ACP is an emerging nonthermal technology, which can be used as a postpackaging decontamination step in industrial settings. This study demonstrated the influence of in-package gas composition, treatment time, post-treatment storage, and ham formulation on L. monocytogenes inactivation efficacy of ACP. Results of present study will be helpful to optimize in-package ACP treatment and storage conditions to reduce L. monocytogenes, while maintaining the quality of ham.

Comparative efficacy of sodium lactate and Natamycin against discoloration and spoilage of fresh beef during chilled storage

“…can inhibit the spoilage bacteria growth such as Serratia spp. and Pseudomonas spp., due to their antibacterial activity and anti-oxidative activities (Yadav et al, 2020). Serratia spp.…”

Effect of Cold Plasma on Meat Cholesterol and Lipid Oxidation

“…However, unlike the beef loin, pork butt samples did not display significant increases in TBARS when compared to the control. In another study [50], ham was packed in three different gas mixtures, namely 20% O 2 , 40% N 2 and 40% CO 2 (treatment 1), 50% CO 2 and 50% N 2 (treatment 2) or 100% CO 2 (treatment 3) and treated at 30 kV for either 5 or 10 min using a dielectric barrier discharge (DBD) plasma system. The authors reported that TBARS values were significantly higher for the treated samples compared with the control.…”

Dielectric barrier discharge cold atmospheric plasma: Influence of processing parameters on microbial inactivation in meat and meat products

“…These species react with different myoglobins in meats and meat products, thereby triggering oxidation of both pigment and lipids that alters the color of the DBD‐CAP‐treated samples. In contrast, the reason for no significant changes in color parameters might be because insufficient reactive species were produced that could not induce oxidation (Chaplot et al., 2019; Jayasena et al., 2015; Jung et al., 2017; Kim et al., 2013; Lee et al., 2016; Moutiq et al., 2019; Olatunde et al., 2019; Roh et al., 2019; Yadav et al., 2020; Yong et al., 2017; Zhuang, Rothrock et al., 2019a; Fröhling et al., 2012).…”

“…For individual pathogens, for example, L. monocytogenes has a high hospitalization rate of > 90% and a fatality ranging from 20% to 30%. Equally, various kinds of meats are discarded annually in huge quantities due to these microorganisms, for example, over 16,000,000 kg of ground turkey was wasted as a result of Salmonella contamination (DeNoon, 2011; Hernandez‐Milian & Payeras‐Cifre, 2014; Roh et al., 2019; Russell, 2009; Tack et al., 2020; Thomas et al., 2015; Yadav et al., 2020; Zhuang, Rothrock et al., 2019a).…”