Phytochemical profile, antibacterial and antibiofilm activity of spice plants against important food pathogens

The spice plants are commonly used to flavor foods, but their nutritional value and antibacterial potential arouse interest in the application of these plants in alternative methodologies for the development of natural preservatives. The study aimed to characterize chemically and evaluate the antibacterial and antibiofilm potential of the essential oils of spicy plants against strains of food interest. The highest concentration of Camphor (37.00%) was observed in R. officinalis, of Geranial (29.85%) in Z. officinale, while the major compound of A. sativum oil was diallyl trisulfide (60.50%). The essential oils demonstrated satisfactory MIC against all bacteria. The best results of R. officinalis oil were observed against S. aureus (MIC 8 μg/mL and MBC 4 μg/mL), while Z. officinale achieved a better effect against E. coli (MIC 4 μg/mL and MBC 4μg/mL), while A. sativum oil, performed better against K. pneumoniae (MIC and MBC of 4 μg/mL). Evaluating the effect of oils on biofilm inhibition, R. officinalis showed no inhibitory effect, Z. officinale satisfactorily inhibited S. aureus and S. Thyphimurium biofilms, and A. sativum inhibited only S. aureus biofilm formation. Compared to the control antibiotic, amoxacillin, the treatments with the essential oils performed better. Due to the concentration and diversity of terpenes and organosulfur compounds, the essential oils of Z. officinale and A. sativum showed antibacterial activity and inhibit the formation of biofilms satisfactorily, configuring themselves as promising alternatives for food preservation and combat of pathogenic microorganisms.