Antibacterial, antifungal and flavor-enhancing properties of essential oils in tomato sauce: Bio-guided fractionation and microencapsulation of Origanum vulgare L. essential oil

Foodborne illnesses caused by bacterial and fungal pathogens such as Staphylococcus aureus, Salmonella enterica and fungi from the Penicillium genus, continue to pose a significant risk to public health. With the increasing consumer demand for safer and more sustainable methods of food preservation, essential oils (EOs) have gained attention as promising natural antimicrobial agents. However, most studies focus on the main components or use preliminary screening methods, with limited investigation of the specific chemical fractions responsible for their bioactivity. The aim of this study was to evaluate the antibacterial and antifungal potential of essential oils from four aromatic plants and one spice. After an initial screening, Origanum vulgare L. (OEO) and Thymus vulgaris L. (TEO) exhibited strong antimicrobial effects and were selected for a more in-depth analysis. A bio-guided fractionation approach was used to isolate and evaluate the antimicrobial activity of their hydrocarbon and oxygenated fractions, revealing that the oxygenated components were primarily responsible for the observed effects. OEO, which was identified as the most effective essential oil, was incorporated into a tomato sauce model system in both free and microencapsulated form. The preservative efficacy of each formulation was tested under simulated storage conditions. Both forms inhibited the growth of the target microorganisms, with the microencapsulated essential oil showing effective activity at lower concentrations. These results support the potential of bio-guided analysis and microencapsulation as complementary strategies to improve the application of essential oils as natural food preservatives.