Thermal Inactivation of Stationary-Phase and Acid-Adapted Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes in Fruit Juices
Abstract:The heat resistance of stationary-phase and acid-adapted Escherichia coli O157:H7, Salmonella enterica (serotypes Typhimurium, Enteritidis, Gaminara, Rubislaw, and Hartford), and Listeria monocytogenes was evaluated in single-strength apple, orange, and white grape juices adjusted to pH 3.9. The heat resistance increased significantly (P < 0.05) after acid adaptation. Salmonella had an overall lower heat resistance than the other pathogens. Acid-adapted E. coli O157:H7 presented the highest heat resistance in all juices at the temperatures tested, with lower z-values than Salmonella and L. monocytogenes. The heat resistance (D 60°C-values) of all three pathogens, assessed in tryptic soy broth adjusted to different pH values, increased above pH 4.0. From the results obtained in this study, one example of a treatment that will inactivate 5 logs of vegetative pathogens was calculated as 3 s at 71.1°C (z-value of 5.3°C). Normal processing conditions calculated for hot-filled, shelf-stable juices achieve a lethality in excess of 50,000 D for all three pathogens.
Document Type: Research Article
Affiliations: Center for the Development of Research Policy & New Technologies, National Food Processors Association, 1350 I Street, N.W. Suite 300, Washington, D.C. 20005, USA
Publication date: 2001-03-01
More about this publication?
- The Journal of Food Protection has moved to a new website. Please use http://jfoodprotection.org to access the Journal of Food Protection and Journal of Milk & Food Technology content on the new JFP site. Content on the IngentaConnect website will not be available after December 31, 2016.
- 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