Impact of the contamination level and the background flora on the growth of Listeria monocytogenes in ready‐to‐eat diced poultry. (28th February 2015)

• Record Type: Journal Article
• Authors: Lardeux, A.‐L.; Guillier, L.; Brasseur, E.; Doux, C.; Gautier, J.; Gnanou‐Besse, N.
• Is Part Of: Letters in applied microbiology. Volume 60:Number 5(2015:May)
• Page Start: 481
• Page End: 490
• Publication Date: 2015-02-28
• Subjects: Microbiology -- Periodicals; 660.62
• DOI: 10.1111/lam.12395
• Languages: English
• ISSNs: 0266-8254

Abstract

<abstract abstract-type="main" id="lam12395-abs-0001"> <title>Abstract</title> <sec id="lam12395-sec-1001" sec-type="section"> <p>The food safety criteria that have been incorporated in European regulation (EC) No2073/2005 (Official Journal of the European Union L, 338, 2005, 1), for <italic>Listeria monocytogenes</italic> in ready‐to eat (RTE) foods, specify a maximum allowable concentration of 100 CFU g<sup>−1</sup> or ml<sup>−1</sup>. Some factors such as pH, salt and modified atmosphere packaging (MAP) are used to prevent the growth of <italic>L. monocytogenes</italic> in order to comply with the limit. Interactions between background microflora (BM) and <italic>L. monocytogenes</italic> may limit the growth of <italic>L. monocytogenes</italic>. The aim of this study was to investigate the mechanisms behind the observed inhibition by natural BM of the growth of <italic>L. monocytogenes</italic> in ready‐to‐eat diced poultry meat whose pH and water activity were favourable to its growth. The dynamics of <italic>L. monocytogenes</italic> and natural BM were therefore monitored in mono‐culture and co‐culture experiments with various combinations of contamination levels. In the absence of BM, the growth potential of <italic>L. monocytogenes</italic> depended only on the initial inoculum. With both BM and <italic>L. monocytogenes</italic>, whatever the combination of concentrations studied, the growth potentials of <italic>L. monocytogenes</italic> were lower than in a mono‐culture through a partial Jameson effect. Thus, the use‐by date of this product can be optimized by using models that take into account interactions with BM.</p> </sec> <sec id="lam12395-sec-1002" sec-type="section"> <title>Significance and Impact of the Study</title> <p>The study of the growth of <italic>Listeria monocytogenes</italic> in a diced poultry meat, a matrix whose pH and water activity characteristics are favourable to <italic>L. monocytogenes</italic> growth, showed that it was inhibited by natural background microflora. This highlights the importance of knowing the product's composition, and in particular the natural background microflora, which can impact the use‐by date.</p> </sec> </abstract>