Salmonella typhimurium is able to form biofilms as a resistance mechanism against antimicrobials; therefore, it represents a problem for assuring food safety and highlights the importance of research on anti‐biofilm technologies. In this study, S. typhimurium biofilms were inactivated with the combination of clove essential oil (CEO) and ultraviolet light (UV‐C). The volatile composition of the CEO determined by gas chromatography showed eugenol as the major constituent (82%). A combination of CEO with UV‐C achieved a complete bacterial reduction (6.8 log/cm2) on biofilms with doses of 1.2 mg/ml and 76.41 mJ/cm2, respectively. Individually, the CEO at 1.2 mg/ml caused a reduction of 1.8 log CFU/cm2 of attached bacteria cells on stainless steel, while UV‐C individually used at 620.4 mJ/cm2 caused a 2.9 log CFU/cm2 reduction compared to control biofilms. In conclusion, this study demonstrated a synergistic effect of combining CEO and UV‐C irradiation to inactivate biofilms of S. typhimurium.

Salmonella can form biofilms that contribute to its resistance in food processing environments. Biofilms are a dense population of cells that adhere to the surface, creating a matrix composed of extracellular polymeric substances (EPS) consisting mainly of polysaccharides, proteins, and eDNA. Remarkably, the secreted substances, including cellulose, curli, and colanic acid, act as protective barriers for Salmonella and contribute to its resistance and persistence when exposed to disinfectants. Conventional treatments are mostly ineffective in controlling this problem; therefore, exploring anti-biofilm molecules that minimize and eradicate Salmonella biofilms is required. The evidence indicated that terpenes effectively reduce biofilms and affect their three-dimensional structure due to the decrease in the content of EPS. Specifically, in the case of Salmonella, cellulose is an essential component in their biofilms, and its control could be through the inhibition of glycosyltransferase, the enzyme that synthesizes this polymer. The inhibition of polymeric substances secreted by Salmonella during biofilm development could be considered a target to reduce its resistance to disinfectants, and terpenes can be regarded as inhibitors of this process. However, more studies are needed to evaluate the effectiveness of these compounds against Salmonella enzymes that produce extracellular polymeric substances.