Short communicationControlling Brochothrix thermosphacta as a spoilage risk using in-package atmospheric cold plasma

- ACP treatment of 30 s reduced planktonic populations of Brochothrix thermosphacta by 5 Log Cycles.
- ACP treatment achieved a 2 Log bacterial reduction of attached cells in a complex meat model system.
- ACP combined with 30% CO2 + 70% O2 MAP has potential to extend raw meat shelf-life.
- Community profiling indicates that this ACP - MAP combination did not introduce risk.
- ACP combined with MAP can control B. thermosphacta as a key spoilage agent of meat.

Brochothrix thermosphacta is the predominant spoilage microorganism in meat and its control in processing environments is important to maintain meat product quality. Atmospheric cold plasma is of interest for control of pathogenic and spoilage microorganisms in foods. This study ascertained the potential of dielectric barrier discharge atmospheric cold plasma (DBD-ACP) for control of B. thermosphacta, taking microbial and food environment factors into consideration, and investigated the shelf-life of lamb chop after in-package plasma treatment in modified atmosphere. Community profiling was used to assess the treatment effects on the lamb microflora.ACP treatment (80 kV) for 30s inactivated B. thermosphacta populations below detection levels in PBS, while 5 min treatment achieved a 2 Log cycle reduction using a complex meat model medium and attached cells. The antimicrobial efficacy of plasma was reduced but still apparent on lamb chop surface-inoculated with high concentrations of B. thermosphacta. Lamb chop treated under modified atmosphere exhibited reduced microbial growth over the product shelf-life and community profiling showed no evident changes to the microbial populations after the treatment. The overall results indicated potential of ACP to enhance microbial control leading to meat storage life extension through adjusting the modality of treatment.