Authentication of the Botanical and Geographical Origin and Detection of Adulteration of Olive Oil Using Gas Chromatography, Infrared and Raman Spectroscopy Techniques: A Review

Olive oil is among the most popular supplements of the Mediterranean diet due to its high nutritional value. However, at the same time, because of economical purposes, it is also one of the products most subjected to adulteration. As a result, authenticity is an important issue of concern among authorities. Many analytical techniques, able to detect adulteration of olive oil, to identify its geographical and botanical origin and consequently guarantee its quality and authenticity, have been developed. This review paper discusses the use of infrared and Raman spectroscopy as candidate tools to examine the authenticity of olive oils. It also considers the volatile fraction as a marker to distinguish between different varieties and adulterated olive oils, using SPME combined with gas chromatography technique.

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Flash Gas Chromatography in Tandem with Chemometrics: A Rapid Screening Tool for Quality Grades of Virgin Olive Oils

Foods ◽

10.3390/foods9070862 ◽

2020 ◽

Vol 9 (7) ◽

pp. 862 ◽

Cited By ~ 1

Author(s):

Sara Barbieri ◽

Chiara Cevoli ◽

Alessandra Bendini ◽

Beatriz Quintanilla-Casas ◽

Diego Luis García-González ◽

...

Keyword(s):

Gas Chromatography ◽

Olive Oil ◽

Virgin Olive Oil ◽

Classification Model ◽

Data Matrix ◽

Rapid Screening ◽

Volatile Fraction ◽

Large Set ◽

Virgin Olive Oils ◽

Olive Oils

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 efficiency of the controls, and also applicable to the industrial sector.

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State-of-the-Art of Analytical Techniques to Determine Food Fraud in Olive Oils

Foods ◽

10.3390/foods10030484 ◽

2021 ◽

Vol 10 (3) ◽

pp. 484

Author(s):

Antia González-Pereira ◽

Paz Otero ◽

Maria Fraga-Corral ◽

Paula Garcia-Oliveira ◽

Maria Carpena ◽

...

Keyword(s):

Gas Chromatography ◽

Liquid Chromatography ◽

Olive Oil ◽

Food Industry ◽

State Of The Art ◽

Analytical Techniques ◽

Complete Analysis ◽

Food Fraud ◽

Olive Oils ◽

Analytical Approaches

The benefits of the food industry compared to other sectors are much lower, which is why producers are tempted to commit fraud. Although it is a bad practice committed with a wide variety of foods, it is worth noting the case of olive oil because it is a product of great value and with a high percentage of fraud. It is for all these reasons that the authenticity of olive oil has become a major problem for producers, consumers, and legislators. To avoid such fraud, it is necessary to develop analytical techniques to detect them. In this review, we performed a complete analysis about the available instrumentation used in olive fraud which comprised spectroscopic and spectrometric methodology and analyte separation techniques such as liquid chromatography and gas chromatography. Additionally, other methodology including protein-based biomolecular techniques and analytical approaches like metabolomic, hhyperspectral imaging and chemometrics are discussed.

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Identification of adulterated olive oil by fusion of near infrared and Raman spectroscopy

Journal of Physics Conference Series ◽

10.1088/1742-6596/1592/1/012041 ◽

2020 ◽

Vol 1592 ◽

pp. 012041

Author(s):

Qiang Xu ◽

Xingxing Yang ◽

Zhui Hu ◽

Yuan Li ◽

Xiao Zheng

Keyword(s):

Raman Spectroscopy ◽

Olive Oil ◽

Near Infrared ◽

Infrared And Raman Spectroscopy

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Evaluation of the Capability of Horizontal ATR-FTMIR and UV-Visible Spectroscopy in the Discrimination of Virgin Olive Oils from the Moroccan Region of Beni Mellal-Khenifra

Journal of Spectroscopy ◽

10.1155/2020/9317350 ◽

2020 ◽

Vol 2020 ◽

pp. 1-9 ◽

Cited By ~ 4

Author(s):

Aimen El Orche ◽

Mustapha Bouatia ◽

Siham Yanisse ◽

Houda Labjar ◽

Mouad Mouhsin ◽

...

Keyword(s):

Olive Oil ◽

Spectral Data ◽

Geographical Origin ◽

Virgin Olive Oil ◽

Correct Classification ◽

Virgin Olive Oils ◽

Olive Oils ◽

Uv Visible ◽

Beni Mellal ◽

Analytical Approaches

One of the most important challenges in the authentication of olive oil is the determination of the geographical origin of virgin olive oil. In this work, we evaluated the capacity of two spectroscopic techniques, UV-Visible and ATR-FTMIR, coupled with chemometric tools to determine the geographical origin of olive oils. These analytical approaches have been applied to samples that have been collected during the period of olive oil production, in the Moroccan region of Beni Mellal-Khenifra. To develop a rapid analysis tool capable of authenticating the geographical origin of virgin olive oils from five geographical areas of the Moroccan region of Beni Mellal-Khenifra, UV-Visible and ATR-FTMIR spectral data were processed by chemometric algorithms. PCA was applied on the spectral data set to represent the data in a very small space, and then discrimination methods were applied on the principal components synthesized by the PCA. The application of the PCA-LDA method on the spectral data of UV-Visible and ATR-FTMIR shows a good ability to classify olive oils according to their geographical origin with a percentage of correct classification that represents 90.24% and 85.87%, respectively, and the processing of the spectral data of UV-Visible and ATR-FTMIR by PCA-SVM allows differentiating correctly between five olive oils with a correct classification rate of 100% and 97.56, respectively. This study demonstrated the feasibility of UV-Visible and ATR-FTMIR fingerprinting (routine technique) for the geographical classification of olive oils in the Moroccan region of Beni Mellal-Khenifra. Such developed methods can be proposed as alternative and complementary methods to authenticate the geographical origin of virgin olive oil.

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FT-NIR the method of choice to verify the authenticity of extra virgin olive oils

NIR news ◽

10.1177/0960336017707869 ◽

2017 ◽

Vol 28 (4) ◽

pp. 6-9 ◽

Cited By ~ 2

Author(s):

John KG Kramer ◽

Hormoz Azizian

Keyword(s):

Fourier Transform ◽

Olive Oil ◽

Near Infrared ◽

Edible Oils ◽

Virgin Olive Oil ◽

Extra Virgin Olive Oil ◽

Volatile Fraction ◽

Olive Oils ◽

Calibration Models ◽

A Minor

Fourier transform near infrared spectroscopy was recently demonstrated to be an excellent method to evaluate the authenticity and adulteration of extra virgin olive oil. Since this method is matrix dependent, it takes a chemical fingerprint of all the components which sets it apart from the targeted methods. Careful examinations of the Fourier transform near infrared spectra lead to the identification of a minor carbonyl overtone absorption at 5269 cm−1 associated with the volatile fraction in extra virgin olive oil that appears to be a reliable indicator of authenticity. The same spectra were used to identify the fatty acids present in the oil using models based on comparison to accurate GC data. Gravimetric mixtures of extra virgin olive oil with refined edible oils were then prepared to develop PLS1 calibration models to identify possible adulterants and by how much. The great varietal difference in olive oils made it necessary to develop four unique sets of PLS1 calibration models for each extra virgin olive oil variety. As a result, an extra virgin olive oil acceptance specification was established.

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Mass Spectroscopic Evaluation of Virgin Olive Oils (VOOs) Fatty Acid Profile in terms of Cultivar, Geographical Origin, Extraction and Packaging Type

Turkish Journal of Agriculture - Food Science and Technology ◽

10.24925/turjaf.v7i5.783-788.2434 ◽

2019 ◽

Vol 7 (5) ◽

pp. 783 ◽

Cited By ~ 1

Author(s):

Didar Ucuncuoglu

Keyword(s):

Fatty Acid ◽

Olive Oil ◽

Oil Quality ◽

Geographic Origin ◽

Analytical Techniques ◽

Storage Conditions ◽

Olive Cultivar ◽

Aegean Region ◽

Olive Oils ◽

Dark Glass

Ensuring the olive oil quality and authenticity has become a great importance for both traditional and emerging olive oil producing countries. The chemical composition in olive oil heavily varies depending on the olive cultivar and its growing region, the agronomic applications, the olive oil production methods and the process and storage conditions. With the help of some analytical techniques and data evaluation methods, it is possible to grade olive oils in terms of their differences. This research examines particularly fatty acid composition of commercial olive oils (2017/2018 season) with mass detector coupled with gas chromatography (GC/MS). Results were evaluated for grading of them according to IOC regulations based on cultivar (ripe or unripe Ayvalik and Memecik), production (organic, stone mill, cold press, two or more centrifugation systems, filtered or unfiltered) and packing type (transparent or dark glass bottle and plastic bottle), and also their geographic origin (Ayvalik and Edremit towns, the Cunda Island, North Aegean region or South Aegean Region). According to overall data processing, virgin olive samples could be successfully distinguished in terms of theirs geographic origin and cultivar roots. Moreover, it was also explained that the effect of process and package type for grading of olive oils as ‘extra virgin’ or ‘virgin’.

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Triacylglycerols Composition and Volatile Compounds of Virgin Olive Oil from Chemlali Cultivar: Comparison among Different Planting Densities

The Scientific World JOURNAL ◽

10.1100/2012/354019 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6 ◽

Cited By ~ 10

Author(s):

Mokhtar Guerfel ◽

Mohamed Ben Mansour ◽

Youssef Ouni ◽

Flamini Guido ◽

Dalenda Boujnah ◽

...

Keyword(s):

Chemical Composition ◽

Olive Oil ◽

Volatile Compounds ◽

Virgin Olive Oil ◽

Planting Density ◽

Major Constituent ◽

Volatile Fraction ◽

Olive Cultivar ◽

Olive Oils

The present study focused on the comparison the chemical composition of virgin olive oil samples obtained from fruits of the main Tunisian olive cultivar (Chemlali) grown in four planting densities (156, 100, 69, and 51 trees ha−1). Despite the variability in the triacylglycerols and volatile compounds composition, the quality indices (free fatty acids, peroxide value, and spectrophotometric indices K232and K270) all of the virgin olive oils samples studied met the commercial standards. Decanal was the major constituent, accounting for about 30% of the whole volatiles. Moreover, the chemical composition of the volatile fraction of the oil from fruits of trees grown at the planting density of 156, 100, and 51 trees ha−1was also characterised by the preeminence of 1-hexanol, while oils from fruits of trees grown at the planting density of 69 trees ha−1had higher content of (E)-2-hexenal (20.3%). Our results confirm that planting density is a crucial parameter that may influence the quality of olive oils.

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Soil geochemistry, edaphic and climatic characteristics as components of Tunisian olive terroirs: Relationship with the multielemental composition of olive oils for their geographical traceability

Euro-Mediterranean Journal for Environmental Integration ◽

10.1007/s41207-021-00241-y ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Fadwa Damak ◽

Mohamed Seddik Mahmoud Bougi ◽

Daisuke Araoka ◽

Koji Baba ◽

Manami Furuya ◽

...

Keyword(s):

Olive Oil ◽

Soil Chemistry ◽

Geographical Origin ◽

Geochemical Processes ◽

Soil Geochemistry ◽

Geochemical Composition ◽

Olive Oils ◽

Climate Parameters ◽

Complex Interactions ◽

Climatic Characteristics

AbstractOlive oil traceability based on the intrinsic chemical composition of the oil is becoming increasingly important due to the prevalence of fraudulent geographical labelling of olive oils. For a traceability tool to be valid, it should be based on olive oil properties that are clearly related to provenance factors. However, multielement analysis of the oil has been used as a traceability tool without any proof of a direct link between the multielemental composition and the geographical origin of the oil. In order to verify this link, Tunisian olive terroir components from the 11 major olive-producing regions were sampled to evaluate the influences of these components (especially soil and climate) on the geochemical composition of Tunisian olive oil. Overall, geochemical processes relating to strontium and rare-earth element (REE) enrichment were found to control the multelemental compositions of Tunisian soils. Even though olive oils from the 11 Tunisian olive-growing regions considered did not strongly reflect the geochemical signatures of the corresponding Tunisian soils, the concentrations of four elements in the oils, namely Fe, Ti, Ni and Ba, showed significant positive Spearman correlations with their concentrations in the bioavailable extracts from those soils. Moreover, there were numerous significant correlations of elements in the olive oil with soil chemical and climate parameters. Our results clearly confirm that the complex interactions of the olives with the climate and soil chemistry during cultivation significantly affect the multielemental composition of the resulting olive oil. This finding implies that the elemental profile of the olive oil is an effective and valid marker of the geographical origin of the oil, as it is significantly linked to oil provenance factors. It also explains the discrepancies between the geochemical signature of an oil and that of the soil in which the olives were grown, as climate parameters affect the transfer of that signature from soil to olives. This work therefore provides the basis for a scientifically based approach to olive oil traceability. The results of this work can be utilized by agricultural authorities to realise the multielement-based traceability of olive oils from various Tunisian regions. Graphic abstract

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

Foods ◽

10.3390/foods11010113 ◽

2022 ◽

Vol 11 (1) ◽

pp. 113

Author(s):

Francesca Calò ◽

Chiara Roberta Girelli ◽

Selina C. Wang ◽

Francesco Paolo Fanizzi

Keyword(s):

Olive Oil ◽

Geographical Origin ◽

Virgin Olive Oil ◽

Geographic Origin ◽

Analytical Techniques ◽

Extra Virgin Olive Oil ◽

Product Authenticity ◽

Mature Field ◽

Analytical Approaches ◽

Origin Assessment

Geographical origin assessment of extra virgin olive oil (EVOO) is recognised worldwide as raising consumers’ awareness of product authenticity and the need to protect top-quality products. The need for geographical origin assessment is also related to mandatory legislation and/or the obligations of true labelling in some countries. Nevertheless, official methods for such specific authentication of EVOOs are still missing. Among the analytical techniques useful for certification of geographical origin, nuclear magnetic resonance (NMR) and mass spectroscopy (MS), combined with chemometrics, have been widely used. This review considers published works describing the use of these analytical methods, supported by statistical protocols such as multivariate analysis (MVA), for EVOO origin assessment. The research has shown that some specific countries, generally corresponding to the main worldwide producers, are more interested than others in origin assessment and certification. Some specific producers such as Italian EVOO producers may have been focused on this area because of consumers’ interest and/or intrinsic economical value, as testified also by the national concern on the topic. Both NMR- and MS-based approaches represent a mature field where a general validation method for EVOOs geographic origin assessment could be established as a reference recognised procedure.

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Exploring the Scientific Interest for Olive Oil Origin: A Bibliometric Study from 1991 to 2018

Foods ◽

10.3390/foods9050556 ◽

2020 ◽

Vol 9 (5) ◽

pp. 556

Author(s):

Astrid Maléchaux ◽

Yveline Le Dréau ◽

Jacques Artaud ◽

Nathalie Dupuy

Keyword(s):

Cluster Analysis ◽

Olive Oil ◽

Analytical Techniques ◽

Strategic Orientation ◽

Bibliometric Study ◽

Scientific Interest ◽

Nutritional Properties ◽

Olive Oils ◽

The Past ◽

Minor Compounds

The authenticity and traceability of olive oils have been a growing concern over the past decades, generating numerous scientific studies. This article applies the tools of bibliometric analyses to explore the evolution and strategic orientation of the research focused on olive oil geographical and varietal origins. A corpus of 732 papers published in 178 different journals between 1991 and 2018 was considered. The most productive journals, authors and countries are highlighted, as well as the most cited articles associated with specific analytical techniques. A cluster analysis on the keywords generates 8 main themes of research, each focused on different analytical techniques or compounds of interest. A network between these thematic clusters and the main authors indicates their area of expertise. The metabolomics methods are drawing increasing interest and studies focused on the relationships between the origin and the sensory or nutritional properties provided by minor compounds of olive oils appear to be future lines of research.

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