Researchers from the University of Nottingham presented their findings at the Society of General Microbiology’s convention in Dublin this week.
The team claims that biofilms, which are bacteria that form communities on surfaces, are much more highly resistant to cleaning products and antibiotics.
In their opinion, a bacterium such as Listeria's success in persisting in processing environments comes partly from its ability to form resistant biofilms, and partly from its tolerance to drying out, thus enabling it to survive on ‘clean’ surfaces.
The researchers said that they also evaluated the influence of different cooked meat juices including beef, pork, lamb, chicken and duck on the attachment of Liseria to surfaces.
"We found significant differences between the ability of Listeria to stick to stainless steel surfaces at different temperatures, depending upon which meat was used,” said Professor Lisa Dodd. “Cooked duck juices at 25°C allowed the highest levels of Listeria attachment.”
Meanwhile, Project ZEAL (Zero Emissions by Advanced cLeaning), led by Birmingham University's chemical engineering department, aims to understand the nature of soils that deposit on process equipment surfaces and to then apply novel measurement techniques to ensure that the right cleaning procedure is chosen and applied with the minimum of environmental impact.
ZEAL is a four year project with funding of £3.6m from the UK Technology Strategy Board.
"The consortium hopes that by better understanding the generic principles of industrial cleaning and the kinds of fouling most commonly encountered, manufacturers can reduce the time and resources they spend on cleaning production equipment between product runs," Dr Milla Shah from the University of Birmingham told FoodProductionDaily.com
The researchers said they have developed a 'cleaning map' through classifying soils based on starch, sugars, proteins and brewery deposits and then relating the physical properties of the soils to the best applicable removal conditions.
A pilot plant will allow the team to test 'traditional' as well as innovative measuring and monitoring techniques to evaluate cleaning rates and interaction with soils, claim the researchers.
"Results from the project will initially be applied in the factories of ZEAL's industrial partners but will be transferable across industry," added Dr Shah.
The project partners include four major manufacturers, Cadbury, Scottish & Newcastle, Unilever HPC, and Glaxo Smith Kline as well as four suppliers, GEA, Alfa Laval, Ecolab and Bruker Optics.