Apply chlorous acid and chlorine dioxide to inhibit growth of L. monocytogenes.
Unlike other meat products, it is difficult to pasteurize caviar without damaging its texture. As an alternative, researchers at Washington State University wanted to evaluate the antimicrobial effect of chlorous acid against L. monocytogenes and endogeneous microflora in caviar held at 3 C and 7 C during a one-month storage period.
A cocktail of L. monocytogenes (ATCC 19114, 7644, 19113) was inoculated onto caviar. The inoculated caviar was dipped for 30 minutes into an antimicrobial solution of sterile water, 250 ppm of chlorous acid, 100 ppm of chlorine dioxide and 200 ppm of peroxyacetic acid. To determine the best treatment time, the inoculated caviar was treated with 250 ppm of chlorous acid for 1, 5, 10 and 20 minutes.
After the treatment was completed, the antimicrobial solution was drained and air-dried under aseptic conditions for 30 minutes. The researchers packed the caviar into sealed plastic containers, and stored the samples at 3 C or 7 C for 30 days. The L. monocytogenes were recovered by plating onto modified Oxford media. Aerobic microflora were recovered on plate count agar medium. The samples were recovered after up to 30 days of treatment.
The chlorous acid and chlorine dioxide inhibited the growth of L. monocytogenes in various caviar samples at 3 C and 7 C. But the treatments of sterile water and peroxyacetic acid were not effective in controlling L. monocytogenes. Chlorine dioxide was more effective in controlling the total aerobic microbe count in caviar than the other antimicrobial agents. Note that it was necessary to dip caviar into chlorous acid for more than 20 minutes in order to prevent the growth of L. monocytogenes at 7 C.
Further information. Joong-Han Shin, Department of Food Science and Nutrition, Washington State University, FSHN 106, P.O. Box 646376, Pullman, WA 99164; phone: 509-335-7778; fax: 509-335-4815; email: email@example.com.
|Printer friendly Cite/link Email Feedback|
|Publication:||Microbial Update International|
|Date:||Dec 1, 2007|
|Previous Article:||New microbial modeling and bioinformatics techniques under development.|
|Next Article:||Control L. monocytogenes, Salmonella on smoked Salmon using lysozyme, nisin coatings.|