Managing Biofilms in Food and Beverage Production

This informal CPD article, Managing Biofilms in Food and Beverage Production is brought to you Diversey, specialists in providing smart, technology-driven, sustainable solutions for cleaning and hygiene. Such sustainable solutions help to increase productivity, food safety and infection prevention, ultimately enhancing Diversey customers’ end user experience.

The presence of Biofilms in food and beverage processing facilities poses significant risks to food safety. As well as causing spoilage, they also harbour and protect some of the main food pathogen bacterias (Listeria, Salmonella and E. Coli). To ensure products are being made in the safest possible environment, a preventative approach to Biofilms should be taken. However, if Biofilms are detected on an equipment’s surface or in a pipe, it is important to decontaminate the area.

Prevention Methods

Cleaning and Disinfection

Effective, verified, and validated cleaning is critical. All phases of the cleaning process need to be followed at the recommended frequency to prevent the formation of Biofilms. It is important to verify that hidden and enclosed food contact surfaces have been cleaned correctly and also be acutely aware that using high-pressure cleaning equipment carries the risk of distributing Biofilms to other areas of the factory.

Good Hygienic Design and Maintenance

The EHEDG (European Hygienic Engineering and Design Group) recommends that all production equipment is designed and installed in such a way that it is cleanable. Download their Hygienic Design guide here (item number 8). It is also important to monitor the surrounding production environment and facilities to make sure they are in good order and well maintained. Welding, rust, cracked seals, and hard to reach places are all hotspots for Biofilms and should be regularly inspected.

Detection Methods

The appropriate detection method will be determined by the type of product that is being produced and the area within the factory that is suspected to contain Biofilm. These include:

• Staining
• Sampling and analysis
• Sensors and detectors

Removal Methods of Biofilms

When the presence of Biofilms is confirmed, there are two methods to use in an attempt to remove it and these are:

1. Physical treatment
2. Chemical treatment

It is important to note that, if the right approach is not taken, it is extremely difficult to remove Biofilm, as research cited in Corcoran et al1 (Nesse et al. and Russo et al.) indicates:

While poor sanitation methods and bacterial reduced susceptibility to the disinfectants used could be the cause, Corcoran et al suggest that a Salmonellabiofilm should also be considered.

Physical Treatment

Scrubbing, scraping, mechanical spraying, pressure spraying, or internal pipe cleaning will be carried out depending on the situation of the Biofilm. In pharmaceutical plants, using heat treatments are commonplace.

Chemical Treatment

A selection from:

• Detergents/descaling agents (typically used on external surfaces and referred to as Open Plant Cleaning (OPC))
• Non-oxidising biocides (note that this will only treat the bacteria and cannot penetrate and remove the biofilm)
• Oxidising biocides (typically more effective than non-oxidising biocides)

Case Study: The Impact of Time, Action, Concentration and Temperature on Biofilm Removal of a CIP system. Results from Diversey laboratory research and development.

Effect of TIME in Removing a Biofilm from a Surface

Percentage of biofilm removed from stainless steel surfaces with circulation cleaning.
Flow = 5 ft/sec. Detergent concentration = 0.4%

Effect of ACTION (Velocity of a Detergent) in Removing a Biofilm from a Surface

Percentage of biofilm removed from stainless steel surfaces at various flow rates of a chlorinated detergent after 5 minutes in a circulation cleaning system.

Effect of CONCENTRATION of Detergent in Removing a Biofilm from a Surface

Percentage of biofilm removed from stainless steel surfaces with various concentrations of a chlorinated detergent in a circulation cleaning system.

Effect of TEMPERATURE in Removing a Biofilm from a Surface

Percentage of biofilm removed from stainless steel surfaces at various temperatures of a chlorinated detergent in a circulation cleaning system. Detergent concentration = 0.4 %v/v.

References and Further Reading

• Corcoran M. et al, Commonly Used Disinfectants Fail To Eradicate Salmonella enterica Biofilms from Food Surface Materials Applied Environmental Microbiology. 2014 Feb; 80(4): 1507–1514.
• EHEDG Hygienic Design Guide.
• Myszka K., Bacterial Biofilms on Food Contact Surfaces – A Review. Pol. J. Food Nutr. Sci., 2011, Vol. 61, No. 3, pp. 173-180.
• Zhao X., Zhao F., Wang J., Zhong N., Biofilm formation and control strategies of foodborne pathogens:food safety perspectives. RSC Adv., 2017,7, 36670-36683.
• Biofilms: Impact on the Food Industry Food Safety Magazine, 2012.

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