Ultrasonic Cleaning of Conveyor Belt Materials Using Listeria monocytogenes as a Model Organism
Abstract:Persistent Listeria monocytogenes contamination of food industry equipment is a difficult problem to solve. Ultrasonic cleaning offers new possibilities for cleaning conveyors and other equipment that are not easy to clean. Ultrasonic cleaning was tested on three conveyor belt materials: polypropylene, acetal, and stainless steel (cold-rolled, AISI 304). Cleaning efficiency was tested at two temperatures (30 and 45°C) and two cleaning times (30 and 60 s) with two cleaning detergents (KOH, and NaOH combined with KOH). Conveyor belt materials were soiled with milk-based soil and L. monocytogenes strains V1, V3, and B9, and then incubated for 72 h to attach bacteria to surfaces. Ultrasonic cleaning treatments reduced L. monocytogenes counts on stainless steel 4.61 to 5.90 log units; on acetal, 3.37 to 5.55 log units; and on polypropylene, 2.31 to 4.40 log units. The logarithmic reduction differences were statistically analyzed by analysis of variance using Statistical Package for the Social Sciences software. The logarithmic reduction was significantly greater in stainless steel than in plastic materials (P < 0.001 for polypropylene, P = 0.023 for acetal). Higher temperatures enhanced the cleaning efficiency in tested materials. No significant difference occurred between cleaning times. The logarithmic reduction was significantly higher (P = 0.013) in cleaning treatments with potassium hydroxide detergent. In this study, ultrasonic cleaning was efficient for cleaning conveyor belt materials.
Document Type: Research Article
Affiliations: 1: Department of Food and Environmental Hygiene, Faculty of Veterinary Medicine, University of Helsinki, Finland; Meat and Fish Hygiene Unit, Department of Food Control and Veterinary Services, Finnish Food Safety Authority Evira, Mustialankatu 3, 00790 Helsinki, Finland 2: Department of Food and Environmental Hygiene, Faculty of Veterinary Medicine, University of Helsinki, Finland 3: VTT Technical Research Centre of Finland, Finland
Publication date: 2007-03-01
- The Journal of Food Protection has moved to a new website. Please use http://jfoodprotection.org to access the Journal of Food Protection and Journal of Milk & Food Technology content on the new JFP site. Content on the IngentaConnect website will not be available after December 31, 2016.
- 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