title: Monitoring psychrotrophic lactic acid bacteria contamination in a ready-to-eat vegetable salad production environment.
abstract: A study monitoring lactic acid bacteria contamination was conducted in a company producing fresh, minimally processed, packaged and ready-to-eat (RTE) vegetable salads (stored at 4°C) in order to investigate the reason for high psychrotrophic LAB levels in the products at the end of shelf-life. Initially, high microbial counts exceeding the established psychrotrophic thresholds (>10(7)-10(8)CFU/g) and spoilage manifestations before the end of the shelf-life (7days) occurred in products containing an assortment of sliced and diced vegetables, but within a one year period these spoilage defects became prevalent in the entire processing plant. Environmental sampling and microbiological analyses of the raw materials and final products throughout the manufacturing process highlighted the presence of high numbers of Leuconostoc spp. in halved and unseeded, fresh sweet bell peppers provided by the supplier. A combination of two DNA fingerprinting techniques facilitated the assessment of the species diversity of LAB present in the processing environment along with the critical point of their introduction in the production facility. Probably through air mediation and surface adhesion, mainly members of the strictly psychrotrophic species Leuconostoc gelidum subsp. gasicomitatum and L. gelidum subsp. gelidum were responsible for the cross-contamination of every vegetable handled within the plant.
authors.affiliation: LFMFP, Laboratory of Food Microbiology and Food Preservation, Department of Food Safety and Food Quality, Faculty of Bioscience Engineering, Ghent University, Member of Food2Know, Coupure Links 653, Gent B-9000, Belgium. Electronic address: Vasileios.Pothakos@UGent.be.
authors.forename: Vasileios
authors.initials: V
authors.lastname: Pothakos
authors.affiliation: BCCM/LMG Bacteria Collection, Faculty of Sciences, Ghent University, K. L. Ledeganckstraat 35, Gent B-9000, Belgium.
authors.forename: Cindy
authors.initials: C
authors.lastname: Snauwaert
authors.affiliation: LM-UGent, Laboratory of Microbiology, Faculty of Sciences, Ghent University, Member of Food2Know, K. L. Ledeganckstraat 35, Gent B-9000, Belgium; BCCM/LMG Bacteria Collection, Faculty of Sciences, Ghent University, K. L. Ledeganckstraat 35, Gent B-9000, Belgium.
authors.forename: Paul
authors.initials: P
authors.lastname: De Vos
authors.affiliation: LM-UGent, Laboratory of Microbiology, Faculty of Sciences, Ghent University, Member of Food2Know, K. L. Ledeganckstraat 35, Gent B-9000, Belgium; BCCM/LMG Bacteria Collection, Faculty of Sciences, Ghent University, K. L. Ledeganckstraat 35, Gent B-9000, Belgium.
authors.forename: Geert
authors.initials: G
authors.lastname: Huys
authors.affiliation: LFMFP, Laboratory of Food Microbiology and Food Preservation, Department of Food Safety and Food Quality, Faculty of Bioscience Engineering, Ghent University, Member of Food2Know, Coupure Links 653, Gent B-9000, Belgium.
authors.forename: Frank
authors.initials: F
authors.lastname: Devlieghere
mesh_terms: D044822:Biodiversity; D002212:Capsicum / Q000382:microbiology; D015169:Colony Count, Microbial; D016172:DNA Fingerprinting; D019649:Food Industry / Q000379:methods* / Q000592:standards; D005516:Food Microbiology; D005798:Genes, Bacterial / Q000235:genetics; D007934:Leuconostoc / Q000235:genetics / Q000302:isolation & purification*; D014675:Vegetables / Q000382:microbiology*
keywords: Leuconostoc gelidum subsp. gasicomitatum; Psychrotrophic LAB; Source tracking; Spoilage; Vegetable salads