Vegetable-inspired biomimetic surfaces for preventing Escherichia coli binding in the food industry

Pathogen contamination of food contact surfaces poses serious public health and economic risks. Bacterial binding to these surfaces enhances microbial resistance to cleaning and disinfection, thus requiring novel antifouling strategies. This study explored a biomimetic approach to surface engineering by replicating the microtopographies of four plant leaves - Tenderheart (TH), Cauliflower (CF), White Cabbage (WC) and Leek (L) - onto wax and silicone substrates, aiming to reduce Escherichia coli binding. The biomimetic surfaces were fabricated using a moulding technique and characterized for topography (Optical Profilometry and Scanning Electron Microscopy), wettability (Water Contact Angle), and surface chemistry (Raman Spectroscopy), before and after conditioning with a casein film. Antifouling performance was evaluated through spray-and-wash (Attachment) and 1-hour static immersion (Retention) assays. All biomimetic surfaces exhibited significantly higher roughness and lower wettability than the flat controls. Silicone biomimetic surfaces, being less wettable, generally outperformed the wax surfaces, reducing bacterial attachment by up to 88 % (CF) and retention by up to 82 % (WC). The L topography consistently demonstrated strong anti-binding activity against E. coli attachment, whereas the WC surface proved particularly effective in reducing bacterial numbers in retention assays. Although conditioning the surfaces with casein partially masked the surface features and increased their wettability, silicone biomimetic surfaces (WC and L) maintained a significant antifouling efficacy (up to 90 % reduction). Overall, higher roughness and low wettability synergistically hindered bacterial colonization. These findings support the potential of nature-inspired surfaces as a promising strategy to minimize bacterial contamination in food processing equipment.