Olive Oil Quality and Authenticity Assessment Aspects Employing FIA-MRMS and LC-Orbitrap MS Metabolomic Approaches

Abstract

Edible vegetable oils comprise integral components of humans' daily diet during the lifetime. Therefore, they constitute a central part of dietary-exposome, which among 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 a 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 analyzed in fast analysis time of 2 and 8 min, 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 analyzed together, providing a holistic quality control workflow for OO.

Isotopic Traceability (13C and 18O) of Greek Olive Oil

“…The mean difference confirms previous results [ 22 , 26 ] and shows that the δ 13 C of biophenolic extracts have same capability to differentiate the geographic origin as δ 13 C of bulk. These observations are in agreement with the findings of a recent study where other analytical techniques were employed and specifically LC-HRMS and FIA-MRMS [ 20 ].…”

“…Additionally, we measured the δ 13 C isotopic values of the samples’ biophenolic extracts in order to see if we can discriminate the geographical region using these values such as δ 13 C in bulk. Part of these samples was analyzed with LC-MS and FIA-MRMS [ 20 ].…”

Geographical Origin Assessment of Extra Virgin Olive Oil via NMR and MS Combined with Chemometrics as Analytical Approaches

“…The results were also supported by parallel isotope ratio MS (IRMS) analyses. Nikou et al, 2020 [ 37 ], recently used flow injection analysis, magnetic resonance mass spectrometry (FIA-MRMS) data to obtain the metabolic profiles of monovarietal EVOO samples (Koroneiki) collected from the main Greek producing regions. In parallel, an LC-Orbitrap MS platform was used to both verify the efficiency of the method and increase the security of identification of the proposed markers.…”

“…For this reason, notwithstanding the well-established importance of genetic characterization, assessment of the geographical origin of EVOO is preferably studied using analytical techniques dedicated to metabolic rather than genomic profiling. Currently, EVOO metabolic profiling generally takes advantage of two analytical techniques, which have been considered in the present review: nuclear magnetic resonance (NMR) [ 35 ] and mass spectrometry (MS) [ 36 , 37 , 38 ]. These techniques are usually associated with chemometrics methods involving metabolomics with the application of statistical analysis to spectroscopic chemical data [ 39 , 40 , 41 ].…”

FoodOmicsGR_RI: A Consortium for Comprehensive Molecular Characterisation of Food Products

“…Our consortium has extensively applied MS-based metabolic profiling to categorise foods such as wine, olive oil, olives, milk, apples grapes, Chios mastic and other foods. Authenticity studies regarding adulteration and geographical and varietal origin have been efficiently addressed by applying different MS-based screening strategies (target, suspect and non-target) [9,[27][28][29][30]95,96]. Hence, efficient classification and discrimination methodologies were developed regarding food samples of different variety, geographical/animal origin or agronomic background, by combining analytical information with advanced chemometrics [28,29].…”