Membrane Damage and Viability Loss of Escherichia coli K-12 and Salmonella Enteritidis in Liquid Egg by Thermal Death Time Disk Treatment

Authors: Ukuku, Dike O.; Jin, Tony; Zhang, Howard

Source: Journal of Food Protection®, Volume 71, Number 10, October 2008 , pp. 1988-1995(8)

Publisher: International Association for Food Protection

Buy & download fulltext article:

Price: $37.00 plus tax (Refund Policy)

Abstract:

Bacterial injury, including leakage of intracellular substance and viability loss, of Escherichia coli K-12 (ATCC 23716) and Salmonella Enteritidis (ATCC 13076) inoculated in liquid egg white and liquid whole egg was determined by thermal death time disk. E. coli K-12 and Salmonella Enteritidis were inoculated in liquid egg white and liquid whole egg to a final count of 7.8 log CFU/ml and were thermally treated with thermal death time disks at room temperature (23°C), 54, 56, 58, and 60°C from 0 to 240 s. Sublethal injury, leakage of intracellular substances, and viability loss of E. coli K-12 and Salmonella Enteritidis was investigated by plating 0.1 ml on selective trypticase soy agar containing 3% NaCl, 5% NaCl, sorbitol MacConky agar, and xylose lysine sodium tetradecylsulfate and nonselective trypticase soy agar. No significant (P > 0.05) differences on percent injury or viability loss for E. coli K-12 and Salmonella populations were determined in all samples treated at 23°C. Sublethal injury occurred in E. coli and Salmonella populations at 54°C or above for 120 s. Viability losses for both bacteria averaged 5 log at 54°C or above for 180 s, and the surviving populations were below detection (<10 CFU/ml). Thermal treatment at 40°C and above led to membrane damage, leakage, and accumulation of intracellular ATP from 2 to 2.5 log fg/ml and UV-absorbing substances of 0.1 to 0.39 in the treated samples. These results indicate similar thermal injury/damage on both E. coli and Salmonella membranes as determined by the amount of inactivation, viability loss, and leakage of intracellular substances of bacteria.

Document Type: Research article

Affiliations: 1: Food Safety Intervention Technologies Research Unit, Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, 600 East Mermaid Lane, Wyndmoor, Pennsylvania 19038, USA

Publication date: 2008-10-01

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

Membrane Damage and Viability Loss of Escherichia coli K-12 and Salmonella Enteritidis in Liquid Egg by Thermal Death Time Disk Treatment

Buy & download fulltext article:

Tools

Key

Text size:

Useful pages