Estudo da adulteração de azeite de oliva por cromatografia gasosa, espectroscopia no infravermelho e métodos quimiométricos

Abstract

The consumption of olive oil has several health benefits, especially when you compare its use with the consumption of other vegetable oils of lower commercial value. Olive oil is rich in oleic acid, a monounsaturated fatty acid that helps lower low-density lipo-protein (LDL) cholesterol. It also contains phenolic compounds, which are antioxidant substances that fight free radicals. Because of these health benefits and its high com-mercial value, olive oil has been the target of adulteration. In order to detect this fraud, new methods have been developed to identify adulteration in olive oil using analytical methods, with the aim of ensuring the quality and authenticity of the product. The aim of this study was to detect adulteration in extra virgin olive oil using analytical methods such as chromatographic analysis using Gas Chromatography (GC) and spectroscopic analysis in the mid-infrared region using Fourier Transform Attenuated Total Reflec-tance (FTIR-ATR). The results obtained through the analysis made it possible to iden-tify the adulteration of two samples of olive oil with vegetable oils of lower added value, by comparing the concentrations of fatty acids found in the samples and the specifica-tions determined by the Food Codex. Mid-infrared spectroscopy analysis detected pos-sible adulteration of olive oil with refined olive oil by identifying the band at 966 cm-1, which is characteristic of trans fatty acids found in refined vegetable oils. The classifi-catory analysis of the results made it possible to identify the variance between the samples and their main differences and similarities, using Principal Component Analysis (PCA). It was also possible to group the samples using hierarchical cluster analysis, which allowed for a better discussion of the results obtained.