Avances analíticos para la mejora de la información sobre seguridad de aceites vegetales y otros productos alimentarios vegetales de alto contenido graso

Abstract

Taking into account the growing concern for food safety, and the current regulations that establish the limits that cannot be exceeded for certain compounds in food commodities, this Thesis aims to develop reproducible analytical methods for the extraction and analysis of organic contaminants, such as mycotoxins, 3-monochloropropanediol (3-MCPD) esters and glycidyl esters and polar pesticides in vegetable oils and other fatty matrices by (ultra)-high performance liquid chromatography ((U)HPLC) coupled with tandem mass spectrometry (MS/MS), and mineral oil hydrocarbons (MOH) by gas chromatography with flame ionization detector (GC-FID). Therefore, different methods were developed, mainly based on chromatographic techniques coupled with mass spectrometry analyzers for the determination of different contaminants and residues in vegetable oils and related matrices. These methods were validated to verify their robustness, sensitivity, and reliability. Furthermore, they were applied to a wide number of samples to check their applicability and provide valuable information regarding the presence of these compounds in the analyzed samples. Firstly, a comprehensive review of the occurrence of contaminants and the most recent analytical methods for their determination in oils and oilseeds was carried out. Consequently, the optimization of extraction, chromatographic and spectrometric conditions was carried out to detect low concentration levels. Finally, the evaluation of the developed methods was performed, and they were applied to different kind of samples such as oils, nuts and processed food. Therefore, the studies included in this Thesis are: 1. Bibliographic review of the occurrence of contaminants in edible oils and oilseeds and their determination in recent years (between 2010 and 2018). This review includes extraction methods, cleaning methods as well as chromatographic and detection techniques mostly used to detect contaminants and residues in oil and related samples. 2. Development and validation of analytical methods for the determination of mycotoxins in vegetable oils and nuts by UHPLCMS/MS. For that purpose, extraction methods based on QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) were developed. These methods were applied to 194 vegetable oil samples and 36 samples of nuts. 3. Development and validation of an analytical method for the direct determination of 3-monochloropropanediol (3-MCPD) esters and glycidyl esters in vegetable oils, and processed foods, based on liquidliquid extraction (LLE) for oils and solid-liquid extraction (SLE) for processed foods with dispersive solid phase extraction (d-SPE) clean-up and analysis by UHPLC-MS/MS. This method was applied to 20 vegetable oils and 4 processed foods. 4. Development and validation of analytical methods for the determination of polar pesticides in vegetable oils and nuts by HPLCMS/MS. The extraction methods were based on LLE for vegetable oils, and QuPPe (Quick Method for the Analysis of Numerous Highly Polar Pesticides) for nuts. A total of 20 samples of vegetable oils and 20 samples of nuts were analyzed. 5. Development and validation of a method based on solid phase extraction (SPE) and GC-FID for the determination of MOH in vegetable oils. A total of 6 samples previously analyzed by more complex techniques in accredited laboratories were studied in order to check the reliability of the method.