Correlation between Major Bioactive Compounds in Essential Oils from Wild and Cultivated Moroccan Plants and their Antibacterial Efficacy against Foodborne Pathogens

Abstract

Foodborne pathogens pose a significant risk due to surface contamination, often from inadequate hygiene or biofilm formation. While chemical disinfectants are commonly used, concerns about harmful by-products have led to the search for natural alternatives. This study aimed to explore the correlation between major compounds and the antibacterial effects of seven Moroccan essential oils (EOs) against common foodborne pathogens. Essential oils were extracted via hydro-distillation and analyzed using gas chromatography-mass spectrometry (GC-MS) and gas chromatography with flame ionization detection (GC-FID). The antibacterial activity was assessed using the disc diffusion method, and multivariate analyses, including principal component analysis (PCA) and hierarchical cluster analysis (HCA), were applied to evaluate correlations between chemical composition and antibacterial efficacy. Forty-five components were identified from the EOs and categorized into 10 chemical classes. Major components included carvacrol (31.93%) in Origanum elongatum, thymol (31.01%) in Thymus vulgaris, linalyl acetate (46.95%) in Citrus aurantium, 1,8-cineole (80.56%) in Eucalyptus globulus, citral (42.69%) in Cymbopogon citratus, borneol (28.10%) in Thymus serpyllum, and camphor (32.25%) in Lavandula stoechas. Strong antibacterial activity was observed in O. elongatum, T. vulgaris, and T. serpyllum, demonstrating bactericidal properties with low minimum inhibitory concentration (MIC) values. In contrast, E. globulus and C. aurantium had higher MIC values. Multivariate analyses revealed that phenols had the most substantial impact on antimicrobial activity, followed by terpenes and alcohols. These findings suggest that Moroccan EOs are promising natural disinfectants for food contact surfaces, reducing the risk of bacterial pathogen transmission.