Skip to main content

Inactivation of Listeria innocua in Nisin-Treated Salmon (Oncorhynchus keta) and Sturgeon (Acipenser transmontanus) Caviar Heated by Radio Frequency

Buy Article:

$37.00 plus tax (Refund Policy)


Recent regulatory concerns about the presence of the pathogen Listeria monocytogenes in ready-to-eat aquatic foods such as caviar has prompted the development of postpackaging pasteurization processes. However, caviar is heat labile, and conventional pasteurization processes affect the texture, color, and flavor of these foods negatively. In this study, chum salmon (Oncorhynchus keta, 2.5% total salt) caviar or ikura and sturgeon (Acipenser transmontanus, 3.5% total salt) caviar were inoculated with three strains of Listeria innocua in stationary phase at a level of more than 107 CFU/g. L. innocua strains were used because they exhibit an equivalent response to L. monocytogenes for many physicochemical processing treatments, including heat treatment. The products were treated by immersion in 500 IU/ml nisin solution and heat processed (an 8-D process without nisin or a 4-D process with 500 IU/ml nisin) in a newly developed radio frequency (RF; 27 MHz) heating method at 60, 63, and 65°C. RF heating along with nisin acted synergistically to inactivate L. innocua cells and total mesophilic microorganisms. In the RF–nisin treatment at 65°C, no surviving L. innocua microbes were recovered in sturgeon caviar or ikura. The come-up times in the RF-heated product were significantly lower compared with the water bath–heated caviar at all treatment temperatures. The visual quality of the caviar products treated by RF with or without nisin was comparable to the untreated control.

Document Type: Research Article

Affiliations: 1: Department of Clinical Nutrition and Dietetics, Faculty of Allied Health Sciences, Hashemite University, Zarqa-Jordan 2: Department of Food Science and Human Nutrition, Box 646376, Washington State University, Pullman, Washington 99164-6376, USA

Publication date: September 1, 2004

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
  • 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

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more