1H NMR-Based Protocol for the Detection of Adulterations of Refined Olive Oil with Refined Hazelnut Oil

AbstractThe aim of this study was to simulate olive oil use and to monitor changes in the profile of fatty acids in home-made preparations using olive oil, which involve repeated heat treatment cycles. The material used in the experiment consisted of extra virgin and refined olive oil samples. Fatty acid profiles of olive oil samples were monitored after each heating cycle (10 min). The outcomes showed that cycles of heat treatment cause significant (p < 0.05) differences in the fatty acid profile of olive oil. A similar trend of differences (p < 0.05) was found between fatty acid profiles in extra virgin and refined olive oils. As expected, the main differences occurred in monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs). Cross-correlation analysis also showed differences between the fatty acid profiles. The most prolific changes were observed between the control samples and the heated (at 180°C) samples of refined olive oil in PUFAs, though a heating temperature of 220°C resulted in similar decrease in MUFAs and PUFAs, in both extra virgin and refined olive oil samples. The study showed differences in fatty acid profiles that can occur during the culinary heating of olive oil. Furthermore, the study indicated that culinary heating of extra virgin olive oil produced results similar to those of the refined olive oil heating at a lower temperature below 180°C.

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Validation of a Method Based on Triglycerides for the Detection of Low Percentages of Hazelnut Oil in Olive Oil by Column Liquid Chromatography

Journal of AOAC International ◽

10.1093/jaoac/90.5.1346 ◽

2007 ◽

Vol 90 (5) ◽

pp. 1346-1353 ◽

Cited By ~ 10

Author(s):

Diego L García-González ◽

María Viera-Macías ◽

Ramón Aparicio-Ruiz ◽

Maria T Morales ◽

Ramón Aparicio

Keyword(s):

Liquid Chromatography ◽

Olive Oil ◽

Carbon Number ◽

Hazelnut Oil ◽

Equivalent Carbon Number ◽

Experimental Conditions ◽

Mathematical Algorithm ◽

Relative Standard ◽

Triglyceride Content ◽

The Difference

Abstract The difference between theoretical and empirical triglyceride content is a powerful tool to detect the presence of any vegetable oil in olive oil. The current drawback of the method is the separation between equivalent carbon number ECN42 compounds, which affects the reliability of the method and, hence, its cutoff limit. The determination of the triglyceride profile by liquid chromatography using propionitrile as the mobile phase has recently been proposed to improve their quantification, together with a mathematical algorithm whose binary response determines the presence or absence of hazelnut oil. Twenty-one laboratories from 9 countries participated in an interlaboratory study to evaluate the performance characteristics of the whole analytical method. Participants analyzed 12 samples in duplicate, split into 3 intercomparison studies. Statistically significant differences due to the experimental conditions were found in some laboratories, which were detected as outliers by use of Cochran's and Grubbs' tests. The relative standard deviations (RSD) for repeatability and reproducibility were determined following the AOAC Guidelines for Collaborative Studies. The analytical properties of the method were determined by means of the sensitivity (0.86), selectivity (0.94), and reliability (72) for a cutoff limit of 8 (probability 94).

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Sterol Fractionation of Refined Olive Oil for Sale in Mediterranean Region with GC-FD, Composition Analysis of Triterpenic Dialkols and Validation

Hacettepe Journal of Biology and Chemistry ◽

10.15671/hjbc.626940 ◽

2019 ◽

pp. 259-266

Author(s):

Fatma Hepsağ ◽

Pembe Çürük

Keyword(s):

Olive Oil ◽

Mediterranean Region ◽

Composition Analysis ◽

Refined Olive Oil

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Evaluation of the methods based on triglycerides and sterols for the detection of hazelnut oil in olive oil

Grasas y Aceites ◽

10.3989/gya.2007.v58.i4.445 ◽

2007 ◽

Vol 58 (4) ◽

Author(s):

Ramón Aparicio ◽

Diego L. García-González ◽

María Viera ◽

Noelia Tena

Keyword(s):

Olive Oil ◽

Hazelnut Oil

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The amounts of oxidized and oligopolymeric triacylglycerols in refined olive oil as a function of crude oil oxidative level

LWT ◽

10.1016/j.lwt.2011.07.008 ◽

2012 ◽

Vol 45 (2) ◽

pp. 186-190 ◽

Cited By ~ 12

Author(s):

Tommaso Gomes ◽

Francesco Caponio ◽

Viviana Durante ◽

Carmine Summo ◽

Vito Michele Paradiso

Keyword(s):

Crude Oil ◽

Olive Oil ◽

Refined Olive Oil

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Traceability of “Tuscan PGI” Extra Virgin Olive Oils by 1H NMR Metabolic Profiles Collection and Analysis

Metabolites ◽

10.3390/metabo8040060 ◽

2018 ◽

Vol 8 (4) ◽

pp. 60 ◽

Cited By ~ 9

Author(s):

Chiara Roberta Girelli ◽

Laura Del Coco ◽

Samanta Zelasco ◽

Amelia Salimonti ◽

Francesca Luisa Conforti ◽

...

Keyword(s):

Olive Oil ◽

1H Nmr ◽

Large Scale ◽

Virgin Olive Oil ◽

Extra Virgin Olive Oil ◽

Added Value ◽

Metabolic Profiles ◽

The European Union ◽

Virgin Olive Oils ◽

Olive Oils

According to Coldiretti, Italy still continues to hold the European Quality record in extra virgin olive oils with origin designation and protected geographical indication (PDO and PGI). To date, 46 Italian brands are recognized by the European Union: 42 PDO and 4 PGI (Tuscan PGI, Calabria PGI; Tuscia PGI and PGI Sicily). Specific regulations, introduced for these quality marks, include the designation of both the geographical areas and the plant varieties contributing to the composition of the olive oil. However, the PDO and PGI assessment procedures are currently based essentially on farmer declarations. Tuscan PGI extra virgin olive oil is one of the best known Italian trademarks around the world. Tuscan PGI varietal platform is rather wide including 31 specific olive cultivars which should account for at least 95% of the product. On the other hand, while the characteristics of other popular Italian extra virgin olive oils (EVOOs) cultivars from specific geographical areas have been extensively studied (such as those of Coratina based blends from Apulia), little is still known about Tuscan PGI EVOO constituents. In this work, we performed, for the first time, a large-scale analysis of Tuscan PGI monocultivar olive oils by 1H NMR spectroscopy and multivariate statistical analyses (MVA). After genetic characterization of 217 leaf samples from 24 selected geographical areas, distributed all over the Tuscany, a number of 202 micro-milled oil samples including 10 PGI cultivars, was studied. The results of the present work confirmed the need of monocultivar genetically certified EVOO samples for the construction of 1H-NMR-metabolic profiles databases suitable for cultivar and/or geographical origin assessment. Such specific PGI EVOOs databases could be profitably used to justify the high added value of the product and the sustainability of the related supply chain.

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Detection of Hazelnut Oil in Virgin Olive Oil by Assessment of Free Sterols and Triacylglycerols

Journal of AOAC International ◽

10.1093/jaoac/84.5.1534 ◽

2001 ◽

Vol 84 (5) ◽

pp. 1534-1542 ◽

Cited By ~ 27

Author(s):

Stefania Vichi ◽

Lorena Pizzale ◽

Emilio Toffano ◽

Renzo Bortolomeazzi ◽

Lanfranco Conte

Keyword(s):

Olive Oil ◽

Solid Phase ◽

Virgin Olive Oil ◽

Hazelnut Oil ◽

Phase Extraction ◽

Silica Column ◽

Free Sterols ◽

Oil Fractions ◽

Triacylglycerol Analysis ◽

Statistical Certainty

Abstract Free sterols were evaluated as factors for discriminating between genuine virgin olive oil and hazelnut-mixed virgin olive oil. Numeric analyses of the results amplified the differences between groups. The application of this method to virgin olive oil samples and their mixtures with 10% hazelnut oil distinguished between genuine and nongenuine virgin olive oil with statistical certainty. Triacylglycerol analysis was tested for the same purpose by using parameter ΔECN42, but although it possessed a discriminating capacity, it alone could not distinguish the aforementioned groups with sufficient certainty. Free Δ7-sterols data were combined with ΔECN42 data into a single discriminating function to improve differentiation and bring more ruggedness, and for detection of low amounts (10%) of hazelnut oil in virgin olive oil. In fact, the values obtained by addition of Δ7-sterol data and ΔECN42 data showed a higher discriminating capacity than single parameters. In a single operation the method produced all the oil fractions necessary for analysis of free sterols and triacylglycerols with ECN42. Solid-phase extraction was applied in substitution of traditional chromatography on a silica column.

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