Preventing bacterial growth on food-processing surfaces
Conventional antimicrobial agents applied to surfaces that come in contact with food and foodstuffs are often volatile, reacting and degrading to release low-molecular–weight compounds into the environment. Polymeric biocide materials are a promising alternative to overcome these limitations. A consortium supported by small and medium-sized enterprises (SMEs) with several related patent-protected concepts set out to develop and demonstrate the use of functionalised polymers for anti-deposit and antimicrobial surfaces with EU funding of the project BIOSURF. Importantly, the team also addressed the development of monitoring technology to ensure marketability and consumer safety throughout the products' lifetime. Researchers identified specific target bacteria through both questionnaires to end users and onsite investigation of packaging materials. They then synthesised antimicrobial amino-functionalised polynorbornenes, the most promising of which were blended with polypropylene and used to coat stainless steel plates. Monitoring technology was developed for both the anti-deposition and antimicrobial characteristics. The former was based on a sensor of biofilm development and the latter using a tailor-made polymerase chain reaction system to identify DNA sequences for detection of the four target bacteria. Plating of stainless steel followed by coating with an antimicrobial polymer significantly increased detachment of microbes from the surface after contact with various foods and foodstuffs. The monitoring system delivered results consistent with conventional biofilm assessments. The anti-fouling technology resulted in the submission of a patent. BIOSURF's anti-fouling surfaces and monitoring system are expected to have major impact on the competitiveness and profitability of SMEs in the food processing industry. Commercialisation will significantly enhance the health and safety of EU consumers as well.