Abstract:
Edible vegetable oils comprise integral components of humans’ daily diet during lifetime. Therefore, they constitute central part of dietary-exposome which amongst other factors regulates human health. In particular, the regular consumption of olive oil (OO) has been largely accepted as a healthy dietary pattern. Responsible for its recognition as a superior edible oil, is its exceptional aroma and flavor. Its unique composition is characterized by high levels of monounsaturated fatty acids and the presence of minor constituents with important biological properties, such as the so-called OO polyphenols. Being a high-added value product, OO suffers from extensive fraud and adulteration phenomena. However, its great chemical complexity, variability and the plethora of parameters affecting OO composition, hamper significantly the selection of the absolute criteria defining quality and authenticity and a reliable and robust methodology is still unavailable. In the current study, Flow Injection Analysis - Magnetic Resonance Mass Spectrometry (FIA-MRMS) was investigated under metabolic profiling concept for the analysis of Greek Extra Virgin Olive Oils (EVOO). More than 200 monovarietal (Koroneiki) EVOO samples were collected from the main Greek OO producing regions and investigated. Both intact oil and the corresponding polyphenols were analysed in fast analysis time of 2 and 8 minutes, respectively. In parallel, an LC-Orbitrap MS platform was used to verify the efficiency of the method as well as a tool to increase the identification confidence of the proposed markers. Based on the results, with FIA-MRMS, comparable and improved projection and prediction models were generated in comparison to those of the more established LC-MS methodology. With FIA-MRMS more statistically significant compounds and chemical classes were identified as quality and authenticity markers, associated with specific parameters i.e. geographical region, cultivation practice and production procedure. Furthermore, it was possible to monitor both lipophilic and hydrophilic compounds with a single analysis. To our knowledge, this approach is among the few studies, in which two FT-MS platforms combining LC and FIA methods were integrated to provide solutions to quality control aspects of OO. Moreover, both lipophilic and hydrophilic components are analysed together providing a holistic quality control workflow for OO.
Keywords:
olive oil, EVOO, FIA-MRMS, LC-Orbitrap MS, Polyphenols, Quality control, Authenticity
