Microorganisms can colonize and subsequently form biofilms on surfaces, which protect them from adverse conditions and make them more resistant than their planktonic free‐living counterparts. This is a major concern in the food industry because the presence of biofilms has significant implications for microbial food contamination and, therefore, for the transmission of foodborne diseases. Adequate hygienic conditions and various preventive and control strategies have consequently been developed to ensure the provision of safe, good‐quality food with an acceptable shelf‐life. This review focuses on the significance of biofilms in the food industry by describing the factors that favor their formation. The interconnected process among bacteria known as “quorum sensing,” which plays a significant role in biofilm development, is also described. Furthermore, we discuss recent strategic methods to detect, quantify, and remove biofilms formed by pathogenic bacteria associated with food processing environments, focusing on the complexity of these microbial communities.

Food contact surfaces are primary sources of bacterial contamination in food industry processes. With the objective of preventing bacterial adhesion and biofilm formation on surfaces, this study evaluated the antimicrobial activity of silver (Ag-NPs) and zinc oxide (ZnO-NPs) nanoparticle-containing polyester surfaces (concentration range from 400 ppm to 850 ppm) using two kinds of bacteria, Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli), and the prevention of bacterial biofilm formation using the pathogen Listeria monocytogenes. The results of antimicrobial efficacy (reductions ≥ 2 log CFU/cm²) showed that at a concentration of 850 ppm, ZnO-NPs were effective against only E. coli (2.07 log CFU/cm²). However, a concentration of 400 ppm of Ag-NPs was effective against E. coli (4.90 log CFU/cm²) and S. aureus (3.84 log CFU/cm²). Furthermore, a combined concentration of 850 ppm Ag-NPs and 400 ppm ZnO-NPs showed high antimicrobial efficacy against E. coli (5.80 log CFU/cm²) and S. aureus (4.11 log CFU/cm²). The results also showed a high correlation between concentration levels and the bacterial activity of Ag–ZnO-NPs (R² = 0.97 for S. aureus, and R² = 0.99 for E. coli). They also showed that unlike individual action, the joint action of Ag-NPs and ZnO-NPs has high antimicrobial efficacy for both types of microorganisms. Moreover, Ag-NPs prevent the biofilm formation of L. monocytogenes in humid conditions of growth at concentrations of 500 ppm. Additional studies under different conditions are needed to test the durability of nanoparticle containing polyester surfaces with antimicrobial properties to optimize their use.

Detection of biofilms on food-contact surfaces is essential for establishing sanitization procedures and avoiding microbial contamination of food products. The objective of our study was to develop a peroxide biodetector, to detect and reveal the presence of biofilms. A positive reaction was observed when biodetector bubbles were formed on stainless steel and polypropylene surfaces. A range of microorganisms able to form biofilms was evaluated. Catalase-positive bacteria: Staphylococcus aureus, Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella enterica ser. Typhimurium and Cronobacter sakazakii were employed as well as the catalase-negative bacterium: Lactobacillus brevis. With the exception of C. sakazakii, all catalase-positive foodborne pathogens forming the biofilms showed a positive detection by the biodetector, being 10⁴ CFU cm⁻² the minimum microbial load detected. The strongest positive reaction was for P. aeruginosa. Results demonstrated the potential of this biodetector to detect biofilms, particularly when used as a tool in the food industry.

The ability of Flavobacterium psychrophilum to adhere to and form biofilms on different types of materials used on rainbow trout (Oncorhynchus mykiss) farms was evaluated in this study. F. psychrophilum NCIMB 1947^T, was inoculated onto a variety of different surfaces, including stainless steel, plastic, glass, wood, and zinc pyrithione encapsulated antibacterial plastic. The samples were then cultured in a humidified chamber or transferred into fish tanks containing either (1) freshwater or (2) filtered lake water. The formation of biofilms was quantified by fluorescent microscopy. F. psychrophilum formed biofilms on all of the surfaces tested; however, the adherence of the bacterium to the antibacterial plastic was much lower than the attachment observed on the other surfaces, illustrating the bacteriostatic properties of this material for F. psychrophilum. Moreover, bacterial numbers were greater on the surfaces maintained in lake water compared with those maintained in freshwater. The mineral composition of the lake water may have been responsible for the increased bacterial adherence observed between the two types of water. Treatment of the water, regular cleaning of equipment and the use of antimicrobial material to house the fish may help reduce biofilm formation by F. psychrophilum in fish farming systems.