Assessment of the Efficiency of a Nanospherical Gallic Acid Dendrimer for Long-Term Preservation of Essential Oils: An Integrated Chemometric-Assisted FTIR Study

Essential oils (EOs) are volatile chemicals very popular in the food, cosmetic and pharmaceutical industry as aromas, fragrances and alternative therapeutic devices. EOs are susceptible to oxidative degradation, loss of quality and alterations of sensory and pharmacological properties with production of smelly or harmful compounds, responsible for allergic reactions. For preventing EOs' spoilage, synthetic preservatives are adopted, but with poor efficiency and danger of health diseases. Natural polyphenols as gallic acid (GA) are proposed as safer alternatives, but the low compatibility with oils limits their efficacy. In this study, a hydrophobic, GA-enriched antioxidant dendrimer (GAD), is advised as an innovative preservative, after due evaluations. Besides oxidation chemical indexes, the desired information was obtained by FTIR spectroscopy assisted by multivariate analysis. For further confirmation, FTIR data were interpreted by considering the area of some selected bands. Iodometric titration, was performed to determine peroxide value (PV), selected as chemical index. GAD showed a preservative power extraordinary better than that of GA and no pro-oxidant action.