DEVELOPING MODEL SYSTEM FOR EVALUATION OF THE EFFICIENCY OF REMOVING BACTERIAL BIOFILMS IN MILKING SYSTEMS IN THE DAIRY INDUSTRY

Microbial damages, caused by biofilm-forming bacteria in the dairy industry, are a fundamental threat to safety and quality of milk products. Since biofilm forming microorganisms in the dairy associated environment may hold spoilage and/or health risks, the effective cleaning and sanitizing procedures are a fundamental requirement to ensure the safety and quality of dairy products. Cleaning and disinfection in food industries have been incorporated into the cleaning-in-place (CIP) regimes which include regular cleaning of processing equipment with alkaline and acidic liquids at high temperatures. In order to ensure the optimal level of equipment hygiene in the dairy industry it is necessary to determine the biofilm removal efficiency of cleaning solutions used for CIP procedures. However, currently there is no standard method available for evaluating and comparing detergents for use in CIP-procedures in the dairy industry under realistic conditions.

We have established a CIP model system to evaluate the effectiveness of cleaning detergents in removing biofilms from the surfaces of stainless steel which is the predominant substrate in milking equipment in dairy farms. The developed system simulates actual farm conditions and is based on Bacillus subtilis spores surrounded by exopolymeric substances, produced by bacteria during biofilm formation. To the best of our knowledge, it is the first and one of a kind model system developed in Israel that enables proper evaluation and comparison of biofilm removal efficiency of detergents used for CIP procedures in the dairy industry.