Biofilm removal is notoriously difficult, but also critical for food safety. Disease-producing bacteria, including Listeria, can be 1,000 times harder to eliminate if it is living in a protective biofilm.
There are three key steps to removing biofilm in a food processing facility: the use of effective cleaning and sanitizing agents, proper exposure time and temperature, and mechanical action. This combination dissolves the biofilm, allowing the sanitizer to kill the bacteria embedded within it. However, the location, age, and history of biofilm formation will determine the variables involved in each step.
1. Establish an effective formulation and concentration of cleaning and sanitizing agents. Traditional disinfectants like bleach do not effectively penetrate and remove the biofilm. However, some sanitizing agents have been found to be effective. For example, ozone, which attacks extracellular polymeric substances, is particularly efficient at penetrating biofilms. However, it is expensive, poisonous and messy, so it should be carefully applied and dried quickly.
2. Once the right sanitizing agents are determined, you’ll need to factor the appropriate exposure time and temperature. Increasing the cleaner concentration for a short period may help remove bacteria that have begun to form a biofilm. Additionally, increased temperature will loosen the biofilm layer, but excessively hot temperatures could cause other problems.
3. Because biofilms can be resistant or immune to high temperatures and chemical agents, mechanical action such as scrubbing or brushing is imperative. Scrubbing or brushing will lift off the biofilm and expose the bacteria underneath to the chemical detergents and sanitizers.
If you’d like to learn more about preventing and removing biofilms, please email me at foodforthought@stellar.net.