title: Spoilage of vacuum-packed beef by the yeast Kazachstania psychrophila.
abstract: A survey of the psychrotolerant yeast microbiota of vacuum-packed beef was conducted between 2010 and 2012. Chilled vacuum-packed beef (n = 50) sampled from 15 different producers was found to have a mean psychrotolerant yeast count of 3.76 log cfu per cm(2). During this assessment, a recently described yeast named Kazachstania psychrophila was shown to be associated with this product. In order to gain basic knowledge about the spoilage potential of K. psychrophila in vacuum-packed beef, challenge studies were performed and the survival of three different K. psychrophila strains was analyzed during storage of artificially contaminated beef. Beef samples were inoculated with the yeasts at a contamination level of 2 log cfu per cm(2). Survival and growth of K. psychrophila strains was monitored on malt extract agar at regular intervals over 84 days. Kazachstania levels rapidly increased about 5 log units within 16 days under chill conditions (4 °C). Gas bubbles were observed after 16 days, while discoloration and production of off-flavors became evident after 42 days in inoculated samples. This study demonstrates for the first time, that the psychrotolerant yeast K. psychrophila is a dominant spoilage microorganism of vacuum-packed beef products stored at low temperatures, causing sensory defects which result in reduced shelf life, and consequently in considerable economic losses.
authors.affiliation: Department of Microbiology and Biotechnology, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, E.-C.-Baumannstraße 20, 95326 Kulmbach, Germany; Department of Microbiology and Biotechnology, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Hermann-Weigmannstraße 1, 24103 Kiel, Germany. Electronic address: Jan.Kabisch@mri.bund.de.
authors.forename: Jan
authors.initials: J
authors.lastname: Kabisch
authors.affiliation: Department of Microbiology and Biotechnology, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, E.-C.-Baumannstraße 20, 95326 Kulmbach, Germany.
authors.forename: Constanze
authors.initials: C
authors.lastname: Erl-Höning
authors.affiliation: Lehrstuhl für Mikrobielle Ökologie, Zentralinstitut für Ernährungs- und Lebensmittelforschung (ZIEL), Wissenschaftszentrum Weihenstephan, Technische Universität München, Weihenstephaner Berg 3, 85354 Freising, Germany.
authors.forename: Mareike
authors.initials: M
authors.lastname: Wenning
authors.affiliation: Department of Microbiology and Biotechnology, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, E.-C.-Baumannstraße 20, 95326 Kulmbach, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Böhnlein
authors.affiliation: Department of Microbiology and Biotechnology, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, E.-C.-Baumannstraße 20, 95326 Kulmbach, Germany; Chair of Food Safety, Faculty of Veterinary Medicine, Ludwig-Maximilians-University Munich, Schönleutnerstraße 8, 85764 Oberschleißheim, Germany.
authors.forename: Manfred
authors.initials: M
authors.lastname: Gareis
authors.affiliation: Department of Microbiology and Biotechnology, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, E.-C.-Baumannstraße 20, 95326 Kulmbach, Germany.
authors.forename: Rohtraud
authors.initials: R
authors.lastname: Pichner
mesh_terms: D000818:Animals; D002417:Cattle; D015169:Colony Count, Microbial; D005506:Food Contamination / Q000032:analysis*; D018857:Food Packaging; D008460:Meat / Q000032:analysis / Q000382:microbiology*; D014618:Vacuum; D015003:Yeasts / Q000254:growth & development*
keywords: Beef microbiota; Food; Meat spoilage; Saccharomycetaceae