ADULTERATION OF ESSENTIAL OILS

Essential oils are concentrated substances obtained from plant extraction.  Large amounts of plant material are necessary to obtain a small volume of essential oil. Brazil is protagonist in the world essential oils market share, however, Brazil does not have current national technical standards about essential oil analysis. The lack of national regulation combined with the unsustainable production of some species creates the possibility of product adulteration, either through dilution in vegetable oils or the addition of synthetic essential oils. This study aimed to develop a method to detect essential oils adulterated with soybean oil. Two different essential oils (lavender and peppermint) were adulterated with soybean oil at concentrations ranging from 0% to 100%. The samples were analyzed using Fourier-transform infrared spectroscopy (FTIR). Statistical analysis were performed using Partial Least Squares regression (PLS) model, which demonstrated good performance metrics with test set R² = 0.9946 and RMSE = 1.8258 for lavander oil; test set R² = 0.9836 and RMSE = 2.5694 for peppermint oil. These results showed that the proposed method is consistent to detect possible adulterations in essential oils, suggesting FTIR application as a rapid alternative method in essential oil quality control.