Printer Friendly

Remove L. monocytogenes biofilms using ultrasound and ozone.

The removal of biofilms is an important aspect of any sanitation program. Biofilms may harbor pathogens and act as a source of post-processing contamination. One pathogen that is ubiquitous throughout the industry is L. monocytogenes.

Due to their resistance to sanitizers and mechanical brushing, biofilms may best be removed by combining different techniques. The combination of power ultrasound and ozone has shown promise for eliminating biofilms of L. monocytogenes. The objective of scientists at the University of Illinois was to determine the ability of power ultrasound and ozonation, used individually and in tandem, to remove L. monocytogenes biofilms from stainless steel chips. The researchers indicate that a combination of both may be an effective treatment for removing biofilm from stainless steel food contact surfaces.

In tests, the scientists inoculated stainless steel chips with L. monocytogenes. Tryptic soy broth was applied to the chips after they were rinsed with a potassium phosphate buffer (PPB, pH 7.0). Power ultrasound at 20 kHz, 100% amplitude and 120 W was applied for 30 sec or 60 sec to a biofilm chip while it was submerged in 250 ml of sterile PPB. Ozone also was cycled through the 250 ml of PPB containing the biofilm chip for 30 sec or 60 sec at concentrations of 0.25 ppm, 0.5 ppm or 1.0 ppm. Power ultrasound and ozonation were also used in tandem for testing their combined effect.

Both treatments separately resulted in a significant reduction in recoverable microbial cells. Power ultrasound was the most effective treatment, yielding a 3.8 [log.sub.10] CFU per ml reduction after 60 sec. For the ozone combined with the ultrasound treatment, reductions were significantly higher than with either treatment independently. There were no recoverable cells after 60 sec of a combined treatment when an ozone concentration of 0.5 ppm was used. This treatment yielded a reduction of 7.31 [log.sub.10] CFU per ml. The research in this area is continuing. Further information. Scott Martin, Department of Food Science and Human Nutrition, University of Illinois, Urbana-Champaign, 1207 W. Gregory Dr., 486 Animal Sciences Laboratory, MC-630, Urbana, IL 61801; phone: 217-244-2877; fax: 217-244-2517; email: semartn@express.cites.uiuc.edu.
COPYRIGHT 2006 Food Technology Intelligence, Inc.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2006, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

Article Details
Printer friendly Cite/link Email Feedback
Publication:Microbial Update International
Date:Apr 1, 2006
Words:365
Previous Article:PEF fluid handling system inactivates microbes in apple cider.
Next Article:High pressure inactivates V. parahaemolyticus and B. cereus.
Topics:


Related Articles
Ozone - solution to indoor air quality problems?
Static application of chemicals best for cleaning biofilms.
Ultrasound inactivates Listeria, Shigella.
Control the growth of biofilms.
Model the heat inactivation of L. monocytogenes in biofilms.
Models predict the heat inactivation of L. monocytogenes in biofilms.
Ionizing air cleaners zapped.
Competitive exclusion bacteria control Listeria.
Novel approaches quantify attachment strength of foodborne pathogens.
Biofilms, long-term persistence of L. monocytogenes remain a challenge.

Terms of use | Privacy policy | Copyright © 2021 Farlex, Inc. | Feedback | For webmasters