Survival and Growth of Psychrotrophic Bacillus cereus in Dry and Reconstituted Infant Rice Cereal

$37.00 plus tax (Refund Policy)

Buy Article:

Abstract:

The potential for growth of enterotoxigenic Bacillus cereus in reconstituted dry foods is a concern, especially when they are consumed by infants or the immunosuppressed. The ability of a four-strain mixture of spores or vegetative cells of psychrotrophic B. cereus to survive in a commercial, dry infant rice cereal as affected by water activity (aw; 0.27 to 0.28, 0.52 to 0.55, and 0.75 to 0.78), pH (5.6 and 6.7), and temperature (5, 25, 35, and 45°C) was investigated. The rate of death of vegetative cells in dry cereal stored for 36 weeks was not affected by aw or pH. Death of spores in cereal stored at 45°C for up to 48 weeks was enhanced at aw 0.78 but was unaffected by pH; loss of viability at 5, 25, and 35°C was largely unaffected by differences in aw. The effect of temperature (8, 15, 21, and 30°C) on outgrowth of spores of B. cereus inoculated at three levels (0.14, 14, and 133 CFU/g, dry weight basis) into cereal reconstituted with apple juice and commercial pasteurized milk (2% fat) was also studied. Outgrowth of spores did not occur in cereal reconstituted with apple juice. Cereal reconstituted with milk and inoculated with 0.14, 14, and 133 spores per g contained >3 log CFU/g within 24, 9, and 6 h, respectively, at 21°C. Populations in cereal reconstituted with milk and inoculated with 133CFU of B. cereus spores per g reached 7.11, 7.72, and 7.40 log CFU/g within 12, 48, and 72 h when stored at 30, 21, and 15°C, respectively. The organism grew in cereal reconstituted with milk and held at 8°C for 72 h; however, enterotoxin was not detected. In reconstituted cereal inoculated with 133 spores per g, enterotoxin was detected (detection limit 16 ng/g) after 24, 48, and 72 h at 30, 21, and 15°C, respectively, when the population of B. cereus reached > 7 log CFU/g. It is recommended that reconstituted infant foods be either consumed immediately or held at ≤ 8°C and consumed within 48 h after preparation.

Document Type: Research Article

Affiliations: Center for Food Safety and Quality Enhancement, University of Georgia, Griffin, Georgia 30223-1797, USA

Publication date: December 1, 1998

More about this publication?
  • IAFP members must first sign in on the right to access full text articles of JFP

    First published in 1937, the Journal of Food Protection®, 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 Members and Institutional subscribers. Online visitors who are not IAFP Members or journal subscribers will be charged on a pay-per-view basis. Information can be obtained by calling +1 800.369.6337; +1 515.276.3344; fax: +1 515.276.8655, E-mail: info@foodprotection.org or Web site: www.foodprotection.org
  • Information for Authors
  • Submit a Paper
  • Subscribe to this Title
  • Membership Information
  • Information for Advertisers
  • ingentaconnect is not responsible for the content or availability of external websites
Related content

Tools

Favourites

Share Content

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
X
Cookie Policy
ingentaconnect 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