Comparison of Oxygen‐ and Nitrogen‐Enriched Atmospheres on the Growth of Listeria Monocytogenes Inoculated on Poultry Breast Fillets

Abstract

AbstractThe growth behavior of Listeria monocytogenes in the presence of typical spoilage microorganisms on poultry breast fillets (Pseudomonas spp., Brochothrix thermosphacta, Enterobacteriaceae, Lactobacillus spp., total viable count) was investigated. The aim of the study was to compare the growth of L. monocytogenes under oxygen‐ and nitrogen‐enriched atmospheres and to figure out possible interactions between L. monocytogenes and typical spoilage microorganisms on skinless poultry breast fillets. Therefore, the natural meat surface was inoculated with L. monocytogenes and packed under two commonly used gas atmospheres (70% O2/30% CO2 and 70% N2/30% CO2). The atmosphere was monitored over the storage period and typical sensory attributes (color, odor, texture, drip loss and general appearance) were evaluated. The results show that the storage under 70% N2/30% CO2 favored the growth of L. monocytogenes in comparison with the 70% O2/30% CO2. Under nitrogen, L. monocytogenes reached a maximal bacterial count of 5.7 (log10 cfu/g) after approximately 500 h of storage, but no specific microorganism could be identified responsible for the favored growth. The growth of L. monocytogenes was suppressed in the oxygen‐enriched atmosphere, whereas B. thermosphacta dominated the spoilage flora. The results indicate that the combination of high oxygen with carbon dioxide and possible interactions with the spoilage background flora cause a delay of the L. monocytogenes growth under 70% O2/30% CO2.Practical ApplicationsFresh poultry meat has become an increasingly popular food during the last 10 years due to its beneficial nutritional composition. From the microbiological point of view, raw poultry meat is sensitive for microbial growth because of its physical and chemical properties. In this context, the prediction of the growth of foodborne pathogenic bacteria e.g., Listeria monocytogenes is of vital importance to ensure a safe poultry production. Therefore, packaging under modified atmosphere conditions is widely established to improve the quality, shelf life as well as safety aspects. Taking into account that the growth of L. monocytogenes is also influenced by the natural spoilage flora of poultry reflects that interactions between the microorganisms have to be considered while packaging poultry filets under modified atmosphere conditions. The present study shows how two commonly used gas mixtures for poultry influence the outgrowth of L. monocytogenes in the presence of the natural background flora.