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Cold Jet – A Novel Technique for Cleaning and Decontaminating Food Processing Areas, Equipment, Carcasses and Foods

Microchem Bioscience, Ltd
Start date
End date
The objectives were to determine whether the Cold Jet system could both clean and disinfect the types of surface typically found in food processing operations, e.g. ceramic tiles, stainless steel, food grade plastics.

Examples of the type of surfaces used in food processing operations will be obtained and deliberately contaminated with cultures of Salmonella enteritidis, Escherichia coli and Listeria monocytogenes. They will be blasted with dry ice pellets using the Cold Jet system. Various parameters of the Cold Jet system such as air flow rate, blast pressure, dry ice pellet flow rate, etc will be optimised to give the greatest possible 'kill' effect on these microorganisms.

The Cold Jet system will be tested in an animal feed production facility in order to determine its suitability for use in a food environment and its suitability for decontaminating animal carcasses and food evaluated.

More information
Modern food operations use a variety of methods for cleaning and disinfecting surfaces and equipment which comes into contact with foods during handling and preparation. Often food processing factories have to conduct an initial clean up of dirt and debris, and although this may leave surface and equipment looking clean, this does not disinfect those surfaces.

Cleaning and disinfection in food processing operations go hand in hand, as a visibly clean surface may not be free of microorganisms, in particular those micro-organisms that can cause food poisoning. Microorganisms such as salmonella, listeria and E. coli are well known to the public as causes of food poisoning.

Foodborne illness due to consumption of foods contaminated with these micro-organisms can vary from sickness and diarrhoea through to severe illness, with the possibility of long term illness or even death. Thus, as well as obtaining surfaces that are visibly clean, food-processing operations must be disinfect those surfaces and equipment that comes into contact with foods.

Methods used for cleaning include using high pressure water hoses, compressed air, steam, cloths and abrasives, whilst methods used to disinfect include the use of chemicals (e.g. bleach), steam and other high temperature/pressure systems. Chemical disinfectants may not be effective if incorrect concentrations are used or insufficient time is allowed for the chemical to work, etc. Thus it was decided to investigate blasting when dry ice as a means of both cleaning and disinfecting food processing equipment and areas. The means of applying dry ice to food processing surfaces was the Cold Jet system, a patented system for dispensing pellets of dry ice by mixing them with compressed air and blasting them from a nozzle at carefully controlled rates.

The final report, "Cold Jet – A Novel Technique for Cleaning and Decontaminating Food Processing Areas, Equipment, Carcasses and Foods" is available at Foodbase, an open access repository of the FSA.

Find more about this project and other FSA food safety-related projects at the Food Standards Agency Research webpage.

Funding Source
Food Standards Agency
Project number
Bacterial Pathogens