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Podeu consultar les dades primàries associades a aquest article a: http://hdl.handle.net/2445/153597, The verification of the geographical origin of extra virgin (EVOO) and virgin olive oil (VOO) is crucial to protect consumers from misleading information. Despite the large number of studies performed, specific markers are still not available. The present study aims to evaluate sesquiterpene hydrocarbons (SHs) as markers of EVOO geographical origin and to compare the discrimination efficiency of targeted profiling and fingerprinting approaches. A prospective study was carried out on 82 EVOOs from seven countries, analyzed by Headspace Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry (HS-SPME-GC-MS). Classification models were developed by Partial Least Square-Discriminant Analysis (PLS-DA) and internally validated (leave 10%-out cross-validation). The percentage of correct classification was higher for the fingerprinting (100%) than for the profiling approach (45.5-100%). These results confirm the suitability of SHs as EVOO geographical markers and establish the fingerprinting as the most efficient approach for the treatment of SH analytical data with this purpose up to date.

The determination of the total hydroxytyrosol (Htyr) and tyrosol (Tyr) content of virgin olive oil is of utmost interest for the International Olive Council (IOC), food authorities, producers, and distributors after the issuing of a health claim that "olive oil polyphenols contribute to the protection of blood lipids from oxidative stress." To address the need of a harmonized and standardized protocol the present study focuses on the extraction solvent of the polar fraction. Aqueous mixtures of methanol and acetonitrile of equal polarity are prepared and comparatively examined. Different analytical approaches (Folin‐Ciocalteu assay, reversed phase chromatography‐diode array‐fluorescence detection, LC‐Orbitrap, LC‐TOF, LC‐TQd, 1H‐NMR) are applied to highlight the extracting efficiency of the tested mixtures regarding the phenolic content and composition. The use of acetonitrile does not have a clear positive effect that could compensate its higher cost, commercial availability, and toxicity. The findings justify further why methanol:water, 80:20 v/v should be retained in a future IOC protocol for the accurate and repeatable determination of total Htyr and Tyr content, which is necessary to support the health claim for "olive oil polyphenols." Practical Applications: The development of a harmonized and standardized methodology for the determination of total Htyr and Tyr content in an explicit manner is a request of the olive oil sector. A tool that can be introduced easily in the olive industry and official laboratories for the control of the label that bears a health claim for "olive oil polyphenols," is also requested by the consumers and the IOC. In this view, the present study contributes to the cornerstone that is the standardization of the extraction solvent.

Dades de l'article publicat a la revista Food Chemistry, Volume 307, 1 March 2020, 125556. El podeu consultar a http://hdl.handle.net/2445/143358, Data base containing SPME-GC-MS raw analytical data obtained and used by Quintanilla-Casas et al. (Food Chemistry, 2020, 125556). Data correspond to 82 authentic and traceable olive oil samples, declared as EVOO by the suppliers obtained in the framework of OLEUM project (EC H2020 Programme 2014–2020) from seven different EU and non-EU countries: Croatia (n=11); Slovenia (SVN) (n=8); Spain (ESP) (n=17); Italy (ITA) (n=15); Greece (GRC) (n=6); Morocco (MAR) (n=15) and Turkey (TUR) (n=10). With the aim of reflecting the real production scenario, EVOO samples in this prospective study were obtained under usual production practices for commercial purposes, and thus consisted of both monovarietal oils as well as market blends of olive cultivars typical of each geographical origin. Briefly, data correspond to SPME-GC-MS scan intensities of the specific sesquiterpene hydrocarbon (SH) ions (m/z 93, 107, 119, 135, 157, 159, 161, 189 and 204) obtained from the Total Ion Current (TIC) between the 18th to the 30th minute. Thus, 2467 scans were obtained for each m/z ion implying 22203 variables per sample., SPME-GC-MS data have been obtained by researchers in the OLEUM project This work was developed in the context of the project OLEUM “Advanced solutions for assuring authenticity and quality of olive oil at global scale”, funded by the European Commission within the Horizon 2020 Program (2014–2020, grant agreement no. 635690). The information and views set out in this article are those of the author(s) and do not necessarily reflect the official opinion of the European Union. Neither the European Union institutions and bodies nor any person acting on their behalf may be held responsible for the use which may be made of the information contained therein. The study was also supported

by the Ministerio de Ciencia, Innovación y Universidades (MICINN) from Spain through the Juan de la Cierva and Ramon y Cajal programs (JCI-2012_13412 and RYC-2017-23601), and by the Ministerio de Educación, Cultura y Deporte (MECD) from Spain through the FPU pre-doctoral program (FPU16/01744).

Dades primàries de l'article publicat a la revista Food Science and Technology 121: 108936, Dataset containing SPME-GC-MS raw analytical data (total ion chromatograms, not aligned) obtained and used by Quintanilla-Casas et al. (LWT - Food Science and Technology 121: 108936). Data correspond to the volatile fingerprint of 174 authentic and traceable virgin olive oil samples previously graded by six official sensory panels (data from 2 outlier samples are not included) in the framework of OLEUM project (EC H2020 Programme 2014–2020). Briefly, data correspond to SPME-GC-MS scan intensities of the total ion chromatogram at each retention time from 5.5 to 61.96 min. These data were aligned and used under a fingerprinting approach by Quintanilla-Casas et al. to develop a classification model (PLS-DA approach) to verify the sensory quality of virgin olive oils, and it was suggested as an instrumental method to support sensory panels., SPME-GC-MS data have been obtained by researchers in the OLEUM project This work was developed in the context of the project OLEUM “Advanced solutions for assuring authenticity and quality of olive oil at global scale”, funded by the European Commission within the Horizon 2020 Program (2014–2020, grant agreement no. 635690). The information and views set out in this article are those of the author(s) and do not necessarily reflect the official opinion of the European Union. Neither the European Union institutions and bodies nor any person acting on their behalf may be held responsible for the use which may be made of the information contained therein. The study was also supported by the Ministerio de Ciencia, Innovación y Universidades (MICINN) from Spain through the Juan de la Cierva and Ramon y Cajal programs (JCI-2012_13412 and RYC-2017-23601), and by the Ministerio de Educación, Cultura y Deporte (MECD) from Spain through the FPU pre-doctoral program (FPU16/01744).

Sensory quality, assessed following a standardized method, is one of the parameters defining the commercial category of virgin olive oil. Considering the difficulties linked to the organoleptic evaluation, especially the high number of samples to be assessed, setting up instrumental methods to support sensory panels becomes a need for the olive oil sector. Volatile fingerprint by Headspace Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry can be an excellent fit-for-purpose tool as the volatile fraction is responsible for virgin olive oil sensory attributes. A fingerprinting approach was applied to the volatile profile of 176 virgin olive oils pre- viously graded by six official sensory panels. The classification strategy consisted in two sequential Partial Least Square-Discriminant Analysis models built with the aligned chromatograms: the first discriminated extra virgin and non-extra virgin samples; the second classified the latter into virgin or lampante categories. Results were satisfactory in the cross-validation by leave 10%-out (97% of correct classification). For external validation, an uncertainty range was set for the prediction models to detect boundary samples, which would be further assessed by the sensory panels. By doing this, a considerable decrease of the panel workload (around 80%) was achieved, while maintaining a highly reliable classification of samples (error rate < 10%).

Toward a harmonized and standardized procedure for the determination of total hydroxytyrosol and tyrosol content in virgin olive oil (VOO), the pros of a recently published in house validated ultra high performance liquid chromatography (UHPLC) protocol are discussed comparatively with those of other procedures that determine directly or indirectly the compounds hosted under the health claim on 'olive oil polyphenols' (EC regulation 432/2012). Authentic VOOs were analyzed with five di erent liquid chromatographic separation protocols and 1H-NMRone in five di erent laboratories with expertise in VOO phenol analysis within three months. Data comparison indicated di erences in absolute values. Method comparison using appropriate tools (Passing-Bablok regression and Bland Altman analyses) for all protocols vs. the UHPLC one indicated slight or statistically significant di erences. The results were also discussed in terms of cost e ectiveness, detection means, standard requirements and ways to calculate the total hydroxytyrosol and tyrosol content. Findings point out that the in-house validated fit for the purpose UHPLC protocol presents certain pros that should be exploited by the interested parties. These are the simplicity of sample preparation, fast elution time that increase the number of samples analyzed per day and integration of well-resolved peaks with the aid of only two commercially available external standards. Importance of correction factors in the calculations is stressed.

The commercial category of virgin olive oil is currently assigned on the basis of chemical-physical and sensory parameters following official methods. Considering the limited number of samples that can be analysed daily by a sensory panel, an instrumental screening tool could be supportive by reducing the assessors' workload and improving their performance. The present work aims to in-house validate a screening strategy consisting of two sequential binary partial least squares-discriminant analysis (PLS-DA) models that was suggested to be successful in a proof-of-concept study. This approach is based on the volatile fraction fingerprint obtained by HS-SPME-GC-MS from more than 300 virgin olive oils from two crop seasons graded by six different sensory panels into extra virgin, virgin or lampante categories. Uncertainty ranges were set for the binary classification models according to sensitivity and specificity by means of receiver operating characteristics (ROC) curves, aiming to identify boundary samples. Thereby, performing the screening approach, only the virgin olive oils classified as uncertain (23.3%) would be assessed by a sensory panel, while the rest would be directly classified into a given commercial category (78.9% of correct classification). The sensory panel's workload would be reduced to less than one-third of the samples. A highly reliable classification of samples would be achieved (84.0%) by combining the proposed screening tool with the reference method (panel test) for the assessment of uncertain samples.

Fast and effective analytical screening tools providing new suitable authenticity markers and applicable to a large number of samples are required to efficiently control the global olive oil (OO) production, and allow the rapid detection of low levels of adulterants even with fatty acid composition similar to OO. The present study aims to develop authentication models for the comprehensive detection of illegal blends of OO with adulterants including different types of high linoleic (HL) and high oleic (HO) vegetable oils at low concentrations (2-10%) based on shotgun triacylglycerol (TAG) profile obtained by Flow Injection Analysis-Heated Electrospray Ionisation-High Resolution Mass Spectrometry (FIA-HESI-HRMS) at a large-scale experimental design. The sample set covers a large natural variability of both OO and adulterants, resulting in more than one thousand samples analysed. A combined PLS-DA binary modelling based on shotgun TAG profiling proved to be a fit for purpose screening tool in terms of efficiency and applicability. The external validation resulted in the correct classification of the 86.8% of the adulterated samples (diagnostic sensitivity = 0.87), and the 81.1% of the genuine samples (diagnostic specificity = 0.81), with an 85.1% overall correct classification (efficiency = 0.85).

In the context of supporting the panel test in the classification of virgin olive oils, the qualitative and quantitative analysis of a number of volatile compounds responsible for their aroma is of great importance. Herein, the data obtained from three laboratories that analyzed the same samples are presented with the view to develop an inter-laboratory validation study of a harmonized solid-phase micro-extraction coupled with gas-chromatography with flame ionized detector (SPME-GC-FID) method for determination of selected volatile compounds. In particular, quantification of the minimum number of key markers responsible for positive attributes (e.g. fruity) and sensory defects was investigated. Three quantification strategies were considered since they can have a notable impact on the effectiveness of the use of markers as well as on the robustness and simplicity of the method that is designed for control laboratories. A peer-validation study indicated repeatability with a mean relative standard deviation (RSD%) lower than 14% except for ethyl propanoate, 3-methyl-1-butanol, 1-octen-3-ol, and (E)-2-decenal. Linearity was satisfactory (R2 > 0.90) for all compounds when the calibration curves were corrected by the internal standard. Several critical issues were identified, such as high RSD% (>50%) in terms of reproducibility for ethyl propanoate, (E)-2-decenal, and possible improvements of the limits of detection (LODs) and quantitation (LOQs) of (E)-2-heptenal, (E,E)-2,4-hexadienal, and (E)-2-decenal. In particular, some compounds (ethyl propanoate, (E)-2-heptenal, 1-octen-3-ol, (E,E)-2,4-hexadienal, (E)-2-decenal and pentanoic acid) showed LOQs that were higher than the concentrations found in some samples. The discussion permitted improvement of the protocol towards the final version for an upcoming full validation process.

This research aims to develop a classification model based on untargeted elaboration of volatile fraction fingerprints of virgin olive oils (n = 331) analyzed by flash gas chromatography to predict the commercial category of samples (extra virgin olive oil, EVOO; virgin olive oil, VOO; lampante olive oil, LOO). The raw data related to volatile profiles were considered as independent variables, while the quality grades provided by sensory assessment were defined as a reference parameter. This data matrix was elaborated using the linear technique partial least squares-discriminant analysis (PLS-DA), applying, in sequence, two sequential classification models with two categories (EVOO vs. no-EVOO followed by VOO vs. LOO and LOO vs. no-LOO followed by VOO vs. EVOO). The results from this large set of samples provide satisfactory percentages of correctly classified samples, ranging from 72% to 85%, in external validation. This confirms the reliability of this approach in rapid screening of quality grades and that it represents a valid solution for supporting sensory panels, increasing the effciency of the controls, and also applicable to the industrial sector.