Predictive modelling of Listeria monocytogenes survival and recovery in salmon and pork subjected to sous vide cooking at 55 °C
Year: 2025
Type: article
Abstract: Mild sous-vide processing is increasingly applied to enhance the sensory and nutritional quality of ready-to-eat foods. However, its microbiological safety remains uncertain, as moderate temperatures may allow survival and recovery of Listeria monocytogenes . This study investigated the behaviour of L. monocytogenes in salmon and pork fillets cooked at 55 °C for 30, 60, or 90 min and subsequently stored at 4 °C or 8 °C for up to 30 days. Two strains, Scott A and CECT 4031, were tested individually and as a cocktail. Outcomes varied according to strain and matrix: complete inactivation occurred only for CECT 4031 in pork, while survival and recovery were consistently detected in other conditions. Slow heating rates (< 2 °C/min) were associated with higher apparent resistance, particularly for Scott A. Inactivation deviated from log-linearity and was best described by the Geeraerd log-linear + tail and Mafart Weibull models, with D-values ranging from 6.8 to 8.3 min. During storage, post-treatment growth occurred in most salmon samples and in pork inoculated with Scott A at 8 °C. Sublethally injured cells recovered, showing maximum growth rates up to 1.0 log CFU g/day and lag phases of 2–14 days. These findings confirm that mild sous-vide treatments at 55 °C do not guarantee complete inactivation of L. monocytogenes, highlighting the need for validation studies that combine lethality and recovery outcomes. Predictive models integrating non-linear inactivation and heterogeneity provide a robust framework for assessing safety in minimally processed foods. • Mild heat treatments at 55 °C exhibited matrix- and strain-dependent lethality. • Slow heating rates favoured thermal adaptation and increased L. monocytogenes resistance. • Tailing effects in survival curves indicated highly resistant subpopulations. • Sublethal injury and lag phase duration shaped post-treatment recovery and growth. • Complete inactivation only for CECT 4031 in pork; others showed survival.
Language: English
Subfield: Biotechnology
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $4,090
OpenAlex ID: W4415907011