title: Quantitative assessment of the Salmonella distribution on fresh-cut leafy vegetables due to cross-contamination occurred in an industrial process simulated at laboratory scale.
abstract: Fecal pathogen distributions in fresh-cut leafy vegetables are essential to develop suitable sampling plans so as to detect pathogen contaminations. In this study, a typical fresh-cut lettuce process was reproduced at pilot scale with different initial inoculum levels of Salmonella on lettuce (6-7, 4 and 1 log CFU/g). The pathogen was determined in all processed lettuce samples (n ≥ 50) and obtained count data were used to fit different probability distributions. The study showed that Salmonella is homogenously distributed on fresh-cut leafy vegetables as a result of processing (mainly washing) at all contamination levels. Negative binomial and Poisson-lognormal distributions were suitable to describe pathogen distribution at the high and medium levels. coefficient of variation modified (CV) indicated no overdispersion (i.e. clustering). Nevertheless, further research will be needed to assess the effect of using disinfectants in washing water on the final distribution pattern of pathogens in processed fresh-cut leafy vegetables.
authors.affiliation: Department of Food Science and Technology, International Campus of Excellence in the AgriFood Sector ceiA3, University of Córdoba, Córdoba, Spain. Electronic address: b42perof@uco.es.
authors.forename: Fernando
authors.initials: F
authors.lastname: Pérez-Rodríguez
authors.affiliation: R&D&i, National Centre for Technology and Food Safety, San Adrian, Spain. Electronic address: mjsaiz@cnta.es.
authors.forename: M José
authors.initials: MJ
authors.lastname: Saiz-Abajo
authors.affiliation: Department of Food Science and Technology, International Campus of Excellence in the AgriFood Sector ceiA3, University of Córdoba, Córdoba, Spain.
authors.forename: R M
authors.initials: RM
authors.lastname: Garcia-Gimeno
authors.affiliation: R&D&i, National Centre for Technology and Food Safety, San Adrian, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Moreno
authors.affiliation: Department of Microbiology and Parasitology, Microbiological Food and Water Laboratory, C.I.F.A., University of Navarra, C/Irunlarrea 1, 31008 Pamplona, Spain. Electronic address: dgonzalez@unav.es.
authors.forename: David
authors.initials: D
authors.lastname: González
authors.affiliation: Department of Microbiology and Parasitology, Microbiological Food and Water Laboratory, C.I.F.A., University of Navarra, C/Irunlarrea 1, 31008 Pamplona, Spain. Electronic address: avitas@unav.es.
authors.forename: Ana Isabel
authors.initials: AI
authors.lastname: Vitas
mesh_terms: D015169:Colony Count, Microbial; D019453:Escherichia coli O157 / Q000302:isolation & purification*; D005511:Food Handling; D005516:Food Microbiology; D018545:Lactuca / Q000382:microbiology*; D019779:Salmonella enterica / Q000302:isolation & purification*
keywords: Bacterial transfer; Food-borne pathogens; Lettuce; Poisson-lognormal; Predictive microbiology; Probability distributions