EVALUATION OF LIPIDS AND THEIR QUALITY IN OLIVE OILS

Abstract

In Mexico, olive oil (OO) production is small, and the consumer is unaware of its classification and quality; therefore, this study aimed to evaluate some simple lipids (SL), compound lipids (CL) and associated lipids (AL) in OO that are marketed in the state of Hidalgo, Mexico (HgoMx) using Fourier transform infrared spectroscopy (FTIR) to determine its quality. The OO samples were: a) a blend of refined OO and virgin OO (OO-Spain), b) extra virgin olive oil (EVOO-Spain), c) EVOO-Mx, d) mixed vegetable oil blend (MVOB-Mx) and e) EVOO-HgoMx. The wave number and functional group in the OOs were identified with FTIR (400-4000 cm^-1). The aliphatic (AI), long-chain aliphatic (LCA), sulfoxide (SI), carbonyl (CI) and aromatic (ARI) indices were calculated by deconvolution of the absorbances of the FTIR bands of each of the OOs. The wavenumbers determined by FTIR of the OOs differed in composition of SL (723, 914, 1648, 1654, and 3006, and 2853-2923 and 2953 cm^-1), CL (970-1070 cm^-1) and AL (1092, 1116 and 1160 cm^-1). Mixtures of OO with other VOB marketed as EVOO [AI (7.02-35.61) and LCA (0.0-115.40)] were detected and quantified, and they presented contaminants that are harmful to health [ARI (0.0-61.17)]. Only EVOO-HgoMx had the quality of an EVOO and a high content of SI (82.06), which are antioxidants. It is imperative to regulate oil production, classification, characterization, authenticity, and deterioration during the sale in Mexico.