Biofilms in the food industry

Biofilms are complex microbial ecosystems formed by one or more species enclosed in an extracellular polymeric matrix (EPS). The matrix has a different composition depending on the type of pathogen, environment, and colonizing species. The biofilm matrix surrounding bacteria makes them tolerant to harsh conditions and resistant to antibacterial treatments.

The presence of more than one bacterial species in a biofilm has important ecological advantages because it can facilitate the biofilm’s attachment to a surface and contribute to its increased resistance to sanitisers and disinfectants.

In the food industry the EPS can attach to hard surfaces or biological structures (vegetables, meat, bones, fruits, etc). Once formed the biofilm provides many advantages to the microbial cells encased in it:

• physical resistance (against desiccation)

• mechanical resistance (against liquid streams in pipelines)

• chemical protection (against chemicals, antimicrobials and disinfectants used in the industry.)

Of particular importance to the food industry is that some biofilms in food factory environments are pathogenic to humans and they can develop on different artificial substrates such as stainless steel, polyethylene, wood, glass, polypropylene, rubber and concrete. The associated effects of these biofilms (pathogenicity and corrosion of metal surfaces etc) are of critical importance as many processes and structures (tanks, pipelines, centrifuges, pasteurisers, and packing tools) can act as surface substrates for biofilm formation at different temperatures and with different colonizing species.

Health impacts of food industry biofilms

Pathogenic biofilms on food surfaces or factory equipment can inoculate food products and cause infection. As an example, toxins secreted by biofilms can contaminate a food surface, causing individual or multiple (in the case of an outbreak) further product inoculations. Either way the presence of biofilms in a food factory puts human health at risk.

The main locations for biofilm development depend on the factory type, but may include water, milk and other liquid pipelines, pasteuriser plates, reverse osmosis membranes, tables, employee gloves, animal carcasses, contact surfaces, storage silos for raw materials and additives, dispensing tubing, packing material, etc. Listed below are three of the most important food borne bacterial pathogens in NZ.

• Bacillus cereus: Resistant to heat, chemical treatments, radiation and industrial pasteurisation processes.

• Listeria monocytogenes: Some examples of foods known to transmit this pathogen are seafood, dairy products, meat, readyto-eat products, fruits, soft cheeses, ice cream, unpasteurised milk, candied apples, frozen vegetables, and poultry.

• Enterohemorrhagic Escherichia coli: Some strains pose a health risk and are noxious foodborne pathogens transmitted by drinking water, fruits and vegetables (tomatoes, melons, parsley, cilantro, lettuce, spinach etc), raw milk or fresh meat.

Given that biofilms are responsible for causing a broad range of chronic illness, it is important to identify and remove them before they can cause harm. A robust preventative cleaning regime is important to prevent them forming.

How can AWS Group help to manage biofilm?

We offer a comprehensive 3 step approach to managing biofilms, supported by a wide range of product solutions. Working directly with customers, we develop the right solution tailored to their unique needs through identification, elimination and ongoing control.

Step 1. Identify: AWS have the in-house resource to work alongside your Quality Assurance or management team to establish a procedure to identify the problem areas in your facility.

Step 2. Eliminate: Developing site specific procedures, assigning the correct product and providing the appropriate staff training and application support are the key to success.

Step 3. Control: Our monthly audit regime will ensure your newly developed mitigation tools are being followed and upheld. Regular reports and inspection findings are integral to ongoing success.

AWS Group have a wide range of high-performance disinfectants and sanitisers, supported by technical expertise available to all sectors of the food industry.

Contact us now regarding your biofilm issues. www.awsgroup.co.nz