Ultrasonic cleaning of conveyor belt materials using Listeria monocytogenes as a model organism.

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).

Ecology of Listeria spp. in a fish farm and molecular typing of Listeria monocytogenes from fish farming and processing companies.

This study focused on the ecology of Listeria monocytogenes in a fish farm by following the changes in its occurrence in different types of samples for a three year period. In addition, L. monocytogenes isolates from different seafood industry areas were compared with pulsed field gel electrophoresis (PFGE) typing to discover possible associations between primary production, further processing and final products.

Pasteurization of rainbow trout roe: Listeria monocytogenes and sensory analyses.

D- and z-values for a mixture of four Listeria monocytogenes strains originating from the roe of different fish species were determined in rainbow trout (Oncorhynchus mykiss) roe. The D60- and D63-values obtained were 1.60 and 0.

Prevalence and location of Listeria monocytogenes in farmed rainbow trout.

A total of 510 rainbow trout originating from fish farms in lakes and sea areas around Finland were studied for the presence of Listeria monocytogenes. Samples were studied as pools from five fish. Gill, viscera, and skin from the pooled samples were analysed separately.

Prevalence of Listeria monocytogenes in, and microbiological and sensory quality of, rainbow trout, whitefish, and vendace roes from Finnish retail markets.

The prevalence of Listeria monocytogenes in retail roe, as well as the microbiological and sensory qualities of the roe, were studied for three fish species under three different storage conditions. A total of 147 Finnish rainbow trout (Oncorhynchus mykiss), whitefish (Coregonus lavaretus), vendace (Coregonus albula), and burbot (Lota lota) roe samples were bought fresh, frozen, or frozen-thawed from Finnish retail markets. The overall prevalence of L.

Methodologies for the characterization of microbes in industrial environments: a review.

There is growing interest in research and development to develop novel tools to study, detect, and characterize microbes and their communities in industrial environments. However, knowledge about their validity in practical industrial use is still scarce. This review describes the advantages and limitations of traditional and molecular methods used for biofilm and/or planktonic cell studies, especially those performed with Listeria monocytogenes, Bacillus cereus, and/or Clostridium perfringens.

Validation of the Hygicult E dipslides method in surface hygiene control: a Nordic collaborative study.

A collaborative study with Enterobacteriaceae was conducted to validate Hygicult E dipslides by comparison with violet red bile glucose agar (VRBGA) contact plates and swabbing, using stainless steel surfaces artificially contaminated with microbes at various levels. Twelve laboratories participated in the validation procedure. The total number of collaborative samples was 108.

Penetration of Bacteria through Microholes in Semirigid Aseptic and Retort Packages.

The penetration of vegetative cells of Enterobacter aerogenes , Bacillus subtilis , Micrococcus varians , and Leuconostoc mesenteraides through laser-drilled holes of diameter 10 to 20 μm in the lid of commercially manufactured semirigid aseptic cups filled with milk chocolate pudding and retort trays filled with spaghetti in meat sauce (only E. aerogenes ) was studied. The ability of bacteria to pass via leakages was determined using an immersion biotest method.

Microbial Evaluation of the Biotransfer Potential from Surfaces with Bacillus Biofilms after Rinsing and Cleaning Procedures in Closed Food-Processing Systems.

The biotransfer potential in food processing is defined as the ability of the microorganisms present on equipment surfaces both before and after cleaning procedures to contaminate products during processing. Growth of Bacillus biofilms was detectable on both stainless-steel and Teflon surfaces after all the cleaning procedures. B.

Epifluorescence Image Analysis and Cultivation of Foodborne Biofilm Bacteria Grown on Stainless Steel Surfaces.

In this study, biofilm was grown on stainless steel surfaces (AISI 304) for 2, 5, and 10 d at 25°C in slime broth inoculated with the food spoilage microbes Bacillus subtilis , Listeria monocytogenes , Pediococcus pentosaceus , and Pseudomonas fragi . The biofilm developing on steel surfaces were investigated using conventional plating, quantitative glycocalyx determination, and epifluorescence microscopy with image analysis. The results showed that B.