title: Validation of a predictive model coupling gas transfer and microbial growth in fresh food packed under modified atmosphere.
abstract: Predicting microbial safety of fresh products in modified atmosphere packaging implies to take into account the dynamic of O2, CO2 and N2 exchanges in the system and its effect on microbial growth. In this paper a mechanistic model coupling gas transfer and predictive microbiology was validated using dedicated challenge-tests performed on poultry meat, fresh salmon and processed cheese, inoculated with either Listeria monocytogenes or Pseudomonas fluorescens and packed in commercially used packaging materials (tray + lid films). The model succeeded in predicting the relative variation of O2, CO2 and N2 partial pressure in headspace and the growth of the studied microorganisms without any parameter identification. This work highlighted that the respiration of the targeted microorganism itself and/or that of the naturally present microflora could not be neglected in most of the cases, and could, in the particular case of aerobic microbes contribute to limit the growth by removing all residual O2 in the package. This work also confirmed the low sensitivity of L. monocytogenes toward CO2 while that of P. fluorescens permitted to efficiently prevent its growth by choosing the right combination of packaging gas permeability value and initial % of CO2 initially flushed in the pack.
authors.affiliation: UMR IATE University of Montpellier, 2 place Pierre Viala, F-34060, Montpellier Cedex, France. Electronic address: valerie.guillard@umontpellier.fr.
authors.forename: V
authors.initials: V
authors.lastname: Guillard
authors.affiliation: LUBEM, 2 Rue de l'Université, F-29334, Quimper, France.
authors.forename: O
authors.initials: O
authors.lastname: Couvert
authors.affiliation: Aérial, 250 rue Laurent Fries, F67412, Illkirch, France.
authors.forename: V
authors.initials: V
authors.lastname: Stahl
authors.affiliation: ACTALIA, Bd du 13 juin 1944 - BP2, 14310, Villers-bocage, France.
authors.forename: A
authors.initials: A
authors.lastname: Hanin
authors.affiliation: ACTALIA, Bd du 13 juin 1944 - BP2, 14310, Villers-bocage, France.
authors.forename: C
authors.initials: C
authors.lastname: Denis
authors.affiliation: ADRIA Développement, Z.A. Creac'h Gwen, F29196, Quimper Cedex, France.
authors.forename: V
authors.initials: V
authors.lastname: Huchet
authors.affiliation: UMR IATE University of Montpellier, 2 place Pierre Viala, F-34060, Montpellier Cedex, France.
authors.forename: E
authors.initials: E
authors.lastname: Chaix
authors.affiliation: LNE, 1, rue Gaston Boissier, 75724, Paris Cedex 15, France.
authors.forename: C
authors.initials: C
authors.lastname: Loriot
authors.affiliation: LNE, 1, rue Gaston Boissier, 75724, Paris Cedex 15, France.
authors.forename: T
authors.initials: T
authors.lastname: Vincelot
authors.affiliation: ADRIA Développement, Z.A. Creac'h Gwen, F29196, Quimper Cedex, France.
authors.forename: D
authors.initials: D
authors.lastname: Thuault
mesh_terms: D001272:Atmosphere; D002245:Carbon Dioxide; D005516:Food Microbiology; D018857:Food Packaging; D005519:Food Preservation; D059022:Food Safety; D005740:Gases; D008089:Listeria monocytogenes / Q000254:growth & development*; D008962:Models, Theoretical; D009584:Nitrogen; D010100:Oxygen; D011551:Pseudomonas fluorescens / Q000254:growth & development*
chemical_list: D005740:Gases; D002245:Carbon Dioxide; D009584:Nitrogen; D010100:Oxygen
keywords: CO(2) antimicrobial effect; Gas transfer; Microbial growth; Modelling; Modified atmosphere packaging; Shelf life