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ARS Home » Northeast Area » Wyndmoor, Pennsylvania » Eastern Regional Research Center » Microbial and Chemical Food Safety » Research » Publications at this Location » Publication #392851
Research Project: Development and Validation of Predictive Models and Pathogen Modeling Programs; and Data Acquisition for International Microbial Databases

Location: Microbial and Chemical Food Safety

Title: Modeling the effects of temperature and pH on Listeria monocytogenes growth in Mexican-style pork chorizo

Author
item GUTIÉRREZ-CHOCOZA, MARIO - Centro De Investigacion En Alimentaction Y Desarollo
item LÓPEZ-ROMERO, JULIO - Universidad De Sonora
item GARCÍA-GALAZ, ALFONSO - Centro De Investigacion En Alimentaction Y Desarollo
item GONZÁLEZ-RÍOS, HUMBERTO - Centro De Investigacion En Alimentaction Y Desarollo
item PEÑA-RAMOS, ETNA - Centro De Investigacion En Alimentaction Y Desarollo
item Juneja, Vijay
item PÉREZ-BÁEZ, ANNA - Centro De Investigacion En Alimentaction Y Desarollo
item VALENZUELA-MELENDRES, MARTÍN - Centro De Investigacion En Alimentaction Y Desarollo

Submitted to: Applied Food Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/17/2023
Publication Date: 8/19/2023
Citation: Gutiérrez-Chocoza, M.A., López-Romero, J.C., García-Galaz, A., González-Ríos, H., Peña-Ramos, E.A., Juneja, V.K., Pérez-Báez, A.J., Valenzuela-Melendres, M. 2023. Modeling the effects of temperature and pH on Listeria monocytogenes growth in Mexican-style pork chorizo. Applied Food Research. 3:100336. https://doi.org/10.1016/j.afres.2023.100336.
DOI: https://doi.org/10.1016/j.afres.2023.100336

Interpretive Summary: Listeria monocytogenes is a continuing concern to the pork industry due to its high prevalence. Fresh pork meat is one of the primary raw materials for producing many typical Mexican meat products, such as chorizo. This emphasizes the need to determine its growth potential in pork to provide an adequate degree of protection against growth of this pathogen. We developed a mathematical model for predicting the growth of this pathogen in pork chorizo as affected by temperature and pH. This model can be used to predict the growth of the pathogen in response to the interaction of these two variables assessed in this study. This information will be of immediate use to consumers and to the food industry and regulatory agencies to guard against the pathogen in pork chorizo.

Technical Abstract: The objective of this work was to study the effect and interaction of temperature (5-30C) and pH (4.5-6.5) on the lag phase (LP), generation time (GT), and exponential growth rate (EGR) of Listeria monocytogenes inoculated in pork chorizo using response surface methodology. Regression models were developed to predict growth parameters. Predictive models were significant (p less than 0.05), had no lack of fit (p more than 0.05) and had an R2 more than 0.94. These criteria indicate that the models satisfactorily describe the experimental data and can be used to estimate the LP, GT, and EGR of L. monocytogenes in pork chorizo as a function of pH and temperature within the studied limits. By simulating the growth of L. monocytogenes under temperature abuse storage and inadequate product’s pH level, risk scenarios were identified. The optimal pH and temperature that maximize LP and GT, and minimize EGR were pH = 4.79 and temperature = 8.66C. Under these conditions, LP = 142 h, GT = 22.3 h, and EGR = 0.0135 Log (CFU/g) per hour were predicted. Pork chorizo producers can use the models generated in this study to estimate the potential risk of L. monocytogenes growth as a function of the pH and temperature within the range established in this work.