(191i) Influence of Chemical Structure of Compounds Present in Essential Oils on Their Antimicrobial Activity

Nowadays, development of healthier and safer alternatives in the food industry is an essential requirement during product and process design. The importance of essential oils (EOs) as food additives to control food spoilage and foodborne pathogenic bacteria has rapidly increased in recent years, since they constitute a natural source to develop new antimicrobial agents. Selected authors have reported synergistic, additive, or antagonistic antimicrobial effects when specific essential oils are mixed, where the antibacterial activity of the mixture depends on the EOs' composition and the target microbial strains. Moreover, some correlations between the molecular structure of several compounds of essential oils and their antimicrobial effect have also been reported.

The objective of this work was to evaluate the possible correlations between the antimicrobial effects of selected EOs with their physicochemical properties. A database of the antimicrobial effects of pure compounds present in EOs, EOs' composition and their minimum inhibitory concentrations against several bacteria (Gram positive or negative), was collected from selected reports. Some physicochemical properties, such as viscosity, vapor pressure, diffusivity in water, and partition coefficients, among others, were estimated by group contribution methods from the molecular structure of the pure components present in studied EOs. Every property estimation was developed by means of the ASPEN PLUS process simulator using the Joback-Reid and Marrero-Gani methods; furthermore, selected mixture properties were also estimated trough the UNIFAC method, taking into account the compounds present in every studied EO. Results were evaluated using the principal components analysis method, indicating the existence of relationships between the physicochemical properties and the EOs' antimicrobial effect on Gram positive or negative bacteria. The obtained results will contribute to the suitable design of food additives in the form of optimal antimicrobial agents from essential oils.