UV disinfection in the meat processing industry

IN AN INCREASINGLY regulated and safety-conscious market, the meat processing industry has to meet ever more stringent standards of hygiene and quality. Microbial growth due to contamination of wash water, brine chillers, meat marinades and pickle injectors can often result in contamination and shortened shelf life. The threat of contamination is further increased as manufacturers respond to demands for less chemical additives and preservatives. A non-chemical disinfection method gaining increasing acceptance is ultraviolet (UV) disinfection. UV kills all known spoilage microorganisms, including bacteria, viruses, yeasts and moulds (and their spores). It is a low maintenance, environmentally friendly technology that eliminates the need for chemical treatment whilst ensuring high levels of disinfection. Virtually any liquid can be effectively treated with UV, including raw municipal water, filtered wash water, process water, brines, marinades, pickles and process effluent. There are two main types of UV technology, based on the type of UV lamps used: low pressure (LP) and medium pressure (MP). LP lamps have a monochromatic UV output (limited to a single wavelength at 254nm), whereas MP lamps have a polychromatic UV output (with an output between 185-400nm). Unlike chemical treatment, UV does not introduce toxins or residues into the process and does not alter the chemical composition, taste, odour or pH of the water or liquid being disinfected.

Applications in meat processing

UV treatment can be used for primary disinfection or as a back-up for other purification methods such as carbon filtration, reverse osmosis or pasteurisation. As UV has no residual effect, the best position for a treatment system is immediately prior to the point of use. This ensures incoming microbiological contaminants are destroyed and there is a minimal chance of post-treatment contamination. Wash/rinse water. Using UV to disinfect the water used to rinse carcasses and to wash process equipment and work surfaces can dramatically decrease contamination, increasing shelf life. UV also reduces the amount of chlorine needed to disinfect rinse and wash water. Brine chillers, meat pickle and marinade injectors. Brines, pickles and marinades can be a prime breeding ground for harmful microorganisms like Listeria and E. coli. Fitting UV systems on recirculating brine chillers and meat pickle and marinade injectors are very effective at destroying these microorganisms. Depending on the model, some UV systems can operate very effectively through a wide range of temperatures and applications - from super-cooled brines to very hot sanitation cycles. Additionally, in marinade applications, operating costs are reduced through less frequent fluid changeover. Clean-in-Place rinse water. It is essential that the CIP final rinse water used to flush out foreign matter and disinfecting solutions is microbiologically safe. Fully automated UV disinfection systems can be integrated with CIP rinse cycles to ensure final rinse water does not reintroduce microbiological contaminants. Because of their mechanical strength, MP lamps are not affected by any sudden changes in the temperature of the CIP water. Filter disinfection. Stored reverse osmosis (RO) and granular activated carbon (GAC) filters can be a breeding ground for bacteria. UV is an effective way of disinfecting both stored RO and GAC filtered water and has been used in the process industries for many years. Dechlorination. GAC filters are also often used to dechlorinate process water, removing the 'off' flavours often associated with chlorine disinfection, meaning the flavour of the final product remains untainted and free from unwanted flavours or odours. Placing UV systems ahead of GAC filters used for dechlorination improves the performance of thNIKE