Automated Rapid Screening of Foods for the Presence of Salmonellae
Abstract:We previously reported an accelerated method to detect salmonellae in foods. It consisted of a preenrichment step (6 h) followed by immunomagnetic separation (IMS) and automated detection, based on positive biochemical characteristics, during overnight incubation. We describe here a simplified procedure with a detection limit of 2 CFU/25 g of food, a procedure that does not require the IMS step. Liquid eggs, milk, ice cream, or poultry were inoculated with Salmonella or non-Salmonella Enterobacteriaceae organisms (2 to 100 CFU/25 g). Following preenrichment for 6 h at 35 C, samples (3 ml) were added to selective liquid media (6 ml). Automated light transmittance was recorded during incubation at 42 C in the BioSys instrument. Salmonella-positive samples were identified by a sharp drop in transmittance (caused by black discoloration of the media) within 18 h of incubation following the formation of hydrogen sulfide and its reaction with iron ions. Detection of 2 to 10 CFU/25 g of the tested foods was completed in 24 h. A total of 24 Salmonella spp., including heat-injured cells, and 37 non-Salmonella Enterobacteriaceae were tested using the procedure.
Document Type: Research Article
Affiliations: Department of Nutrition and Food Science, Wayne State University, Detroit, Michigan 48202, USA
Publication date: November 1, 1999
More about this publication?
- IAFP Members with personal subscriptions to JFP Online: To access full-text JFP or JMFT articles, you must sign-in in the upper-right corner using your Ingenta sign-in details (your IAFP Member Login does not apply to this website). The Journal of Food Protection (JFP) is a refereed monthly publication. Each issue contains scientific research and authoritative review articles reporting on a variety of topics in food science pertaining to food safety and quality. The Journal is internationally recognized as the leading publication in the field of food microbiology with a readership exceeding 11,000 scientists from 70 countries. The Journal of Food Protection is indexed in Index Medicus, Current Contents, BIOSIS, PubMed, Medline, and many others.
Print and online subscriptions are available to IAFP Members and institutional subscribers. IAFP Members with a subscription to JFP Online will have access to all available JFP and JMFT content. Online visitors who are not IAFP Members or journal subscribers will be charged on a pay-per-view basis. Membership and subscription information is available at www.foodprotection.org.
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Membership Information
- Information for Advertisers
- Ingenta Connect is not responsible for the content or availability of external websites