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Characterization of Olive Products from Greece

A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Natural Products Chemistry".

Deadline for manuscript submissions: closed (31 August 2021) | Viewed by 41412

Special Issue Editors

Laboratory of Analytical Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis Zografou, 157 71 Athens, Greece
Interests: emerging contaminants; (bio)transformation products; fate; ecotoxicology; analytical methods
Special Issues, Collections and Topics in MDPI journals
Food Analytical and Research Laboratories of Athens, Directorate of Laboratories, Hellenic Food Authority (EFET) 143 42, 31 Anagenniseos str, Nea Philadelfeia, Athens, Greece
Interests: food safety; food quality; food authenticity; food microbiology; biotransformation of agroindustrial byproducts
Laboratory of Pomology, School of Agriculture, Aristotle University of Thessaloniki, 570 01 Thessaloniki-Thermi, Greece
Interests: fruit ripening biology; fruit tree physiology; metabolomics; olive cultivation; proteomics

Special Issue Information

Dear Colleagues,

Many projects are currently in progress for the molecular characterization of olive products in Greece (including olive oil, table olives, olive drupes and leaves, and olive mill waste) using a diverse mixture of techniques (MS, NGS, and various applied spectroscopic methods). This is an overall enormous effort of different research groups to reveal the quality, uniqueness, and authenticity of olive products from Greek varieties.

The aims of all these efforts are the following:

  1. To substantiate the authenticity and quality of Greek-originated olive products;
  2. To reveal the bioactive substances in these products;
  3. To explore possibilities for new products with high added value.

Although highly regulated, it is acknowledged that there are still problems in the olive oil sector because fats and oils, including olive oils, are ranked third, after meat and meat products and fish and fish products, in the 2016 EU Food Fraud report on non-compliances per product category. For this reason, EU legislation continuously chases after emerging frauds, with the process of proposing new methods with more efficient analytical solutions to reduce time and/or solvent consumption being constantly in progress.

Furthermore, developments and innovations for the determination and preservation of bioactive compounds in olive oil and edible olives are of utmost importance for proposing health and nutritional claims, other than those already regulated, while olive variety, maturity, processing, and storage, as well as debittering techniques and microbiome, play an essential role.

In light of the numerous advances made in recent years on the above points, this Special Issue will extensively cover the combination of existing and novel analytical techniques and metabolomics approaches for the characterization of Greek olive oil and edible oil authenticity and quality. Scientists are warmly invited to submit their original contributions (reviews, original research papers, and short communication) to this Special Issue, which will be of interest to a wide range of readers. In the cases of review articles, an additional, brief (1–2 pages) description of the topic, including a draft index, is required. This preliminary step is essential to avoid overlapping of topics.

Prof. Dr. Nikolaos S. Thomaidis
Dr. Fragiskos Gaitis
Prof. Dr. Athanassios Molassiotis
Guest Editors

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Keywords

  • olive oil
  • table olives
  • olive drupes
  • olive leaves
  • metabolomics
  • omics approaches
  • authenticity
  • quality
  • origin
  • bioactive substances

Published Papers (13 papers)

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Research

21 pages, 3014 KiB  
Article
Comparative Evaluation of Different Targeted and Untargeted Analytical Approaches to Assess Greek Extra Virgin Olive Oil Quality and Authentication
by Sofia Drakopoulou, Emmanouil Orfanakis, Ioulia Karagiannaki, Fragiskos Gaitis, Stavroula Skoulika, Andreas Papaioannou, George Boukouvalas, George Petropoulos, Vassilios Katsoudas, Renate Kontzedaki, Aggelos Philippidis, Aikaterini Zoumi, Marilena Dasenaki, Nikolaos S. Thomaidis and Michalis Velegrakis
Molecules 2022, 27(4), 1350; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27041350 - 16 Feb 2022
Cited by 8 | Viewed by 3118
Abstract
Extra virgin olive oil (EVOO) is a key component of the Mediterranean diet, with several health benefits derived from its consumption. Moreover, due to its eminent market position, EVOO has been thoroughly studied over the last several years, aiming at its authentication, but [...] Read more.
Extra virgin olive oil (EVOO) is a key component of the Mediterranean diet, with several health benefits derived from its consumption. Moreover, due to its eminent market position, EVOO has been thoroughly studied over the last several years, aiming at its authentication, but also to reveal the chemical profile inherent to its beneficial properties. In the present work, a comparative study was conducted to assess Greek EVOOs’ quality and authentication utilizing different analytical approaches, both targeted and untargeted. 173 monovarietal EVOOs from three emblematic Greek cultivars (Koroneiki, Kolovi and Adramytiani), obtained during the harvesting years of 2018–2020, were analyzed and quantified as per their fatty acids methyl esters (FAMEs) composition via the official method (EEC) No 2568/91, as well as their bioactive content through liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS) methodology. In addition to FAMEs analysis, EVOO samples were also analyzed via HRMS-untargeted metabolomics and optical spectroscopy techniques (visible absorption, fluorescence and Raman). The data retrieved from all applied techniques were analyzed with Machine Learning methods for the authentication of the EVOOs’ variety. The models’ predictive performance was calculated through test samples, while for further evaluation 30 commercially available EVOO samples were also examined in terms of variety. To the best of our knowledge, this is the first study where different techniques from the fields of standard analysis, spectrometry and optical spectroscopy are applied to the same EVOO samples, providing strong insight into EVOOs chemical profile and a comparative evaluation through the different platforms. Full article
(This article belongs to the Special Issue Characterization of Olive Products from Greece)
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22 pages, 5996 KiB  
Article
Development of Analytical Strategies for the Determination of Olive Fruit Bioactive Compounds Using UPLC-HRMS and HPLC-DAD. Chemical Characterization of Kolovi Lesvos Variety as a Case Study
by Ioannis Martakos, Panagiota Katsianou, Georgios Koulis, Elvira Efstratiou, Eleni Nastou, Stylianos Nikas, Marilena Dasenaki, Michalis Pentogennis and Nikolaos Thomaidis
Molecules 2021, 26(23), 7182; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules26237182 - 26 Nov 2021
Cited by 4 | Viewed by 2484
Abstract
In this study, an overall survey regarding the determination of several bioactive compounds in olive fruit is presented. Two methodologies were developed, one UPLC-Q-TOF-MS method for the determination of olive fruit phenolic compounds and one HPLC-DAD methodology targeting the determination of pigments (chlorophylls [...] Read more.
In this study, an overall survey regarding the determination of several bioactive compounds in olive fruit is presented. Two methodologies were developed, one UPLC-Q-TOF-MS method for the determination of olive fruit phenolic compounds and one HPLC-DAD methodology targeting the determination of pigments (chlorophylls and carotenoids), tocopherols (α-, β, -γ, δ-) and squalene. Target and suspect screening workflows were developed for the thorough fingerprinting of the phenolic fraction of olives. Both methods were validated, presenting excellent performance characteristics, and can be used as reliable tools for the monitoring of bioactive compounds in olive fruit samples. The developed methodologies were utilized to chemical characterize the fruits of the Kolovi olive variety, originating from the island of Lesvos, North Aegean Region, Greece. Twenty-five phenolic compounds were identified and quantified in Kolovi olives with verbascoside, hydroxytyrosol, oleacein and oleomissional found in significantly high concentrations. Moreover, 12 new bioactive compounds were identified in the samples using an in-house suspect database. The results of pigments analysis suggested that Kolovi variety should be characterized as low pigmentation, while the tocopherol and squalene content was relatively high compared to other olive varieties. The characterization of Kolovi olive bioactive content highlighted the high nutritional and possible economic value of the Kolovi olive fruit. Full article
(This article belongs to the Special Issue Characterization of Olive Products from Greece)
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9 pages, 798 KiB  
Communication
On the Squalene Content of CV Chondrolia Chalkidikis and Chalkidiki (Greece) Virgin Olive Oil
by Aspasia Mastralexi and Maria Z. Tsimidou
Molecules 2021, 26(19), 6007; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules26196007 - 03 Oct 2021
Cited by 8 | Viewed by 1991
Abstract
This work is a continuation of efforts to establish the nutritional profile of virgin olive oil (VOO) from cv. Chondrolia Chalkidikis and Chalkidiki and to strengthen its positioning in the global VOO landscape. VOOs produced at an industrial scale in different olive mills [...] Read more.
This work is a continuation of efforts to establish the nutritional profile of virgin olive oil (VOO) from cv. Chondrolia Chalkidikis and Chalkidiki and to strengthen its positioning in the global VOO landscape. VOOs produced at an industrial scale in different olive mills of the Chalkidiki (Greece) regional unit as well as VOOs obtained at the laboratory scale from drupes of different maturity stages for four consecutive harvesting years were examined for their squalene (SQ) content using both HPLC and GC procedures. The mean values of SQ were found to be 4228 (HPLC) and 4865 (GC) mg/kg oil (n = 15) and were of the same magnitude as that in VOOs from cv Koroneiki (4134 mg/kg, n = 23). Storage of VOOs in the dark at room temperature for 18 months indicated an insignificant mean SQ content loss (~2%) in comparison to a mean loss of 26% for alpha-tocopherol content. This finding strengthens our view that SQ does not act as a radical scavenger that donates hydrogen atoms to the latter. The four consecutive harvest years studied indicated a clear declining trend in VOO SQ concentration upon olive ripening. To our knowledge, this is the first systematic work concerning the SQ content of Chondrolia Chalkidikis and Chalkidiki VOOs. Full article
(This article belongs to the Special Issue Characterization of Olive Products from Greece)
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19 pages, 4082 KiB  
Article
Characterization of the Phenolic Fingerprint of Kolovi Extra Virgin Olive Oils from Lesvos with Regard to Altitude and Farming System Analyzed by UHPLC-QTOF-MS
by Natasa P. Kalogiouri, Evangelia Kritikou, Ioannis C. Martakos, Constantina Lazarou, Michalis Pentogennis and Nikolaos S. Thomaidis
Molecules 2021, 26(18), 5634; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules26185634 - 17 Sep 2021
Cited by 3 | Viewed by 2423
Abstract
Extra virgin olive oil (EVOO) is recognized for its nutritional virtues and the beneficial health effects deriving from its hydrophilic fraction (phenolic acids, phenolic alcohols, flavonoids, and secoiridoids). The phenolic compounds of EVOOs possess multiple biological properties such as antioxidant, antimicrobial, anticarcinogenic, and [...] Read more.
Extra virgin olive oil (EVOO) is recognized for its nutritional virtues and the beneficial health effects deriving from its hydrophilic fraction (phenolic acids, phenolic alcohols, flavonoids, and secoiridoids). The phenolic compounds of EVOOs possess multiple biological properties such as antioxidant, antimicrobial, anticarcinogenic, and anti-inflammatory properties, among others. Considering that EVOOs produced in Greece are recognized as high-quality products due to their rich phenolic content, it is imperative to characterize Greek monovarietal EVOOs and ensure that their uniqueness is closely linked to their botanical and territorial origin. In this work, an ultra-high-performance liquid chromatography–quadrupole time-of-flight tandem mass spectrometry (UHPLC-QTOF-MS) analytical method combined with target and suspect screening was used to characterize monovarietal EVOOs of the Kolovi variety from Lesvos, and thereby establish their phenolic fingerprint. Overall, 25 phenols were determined, and the total quantification and semi-quantification results ranged between 251 and 1230 mg/kg, highlighting the high phenolic content of the Kolovi variety from the island of Lesvos in the North Aegean. Full article
(This article belongs to the Special Issue Characterization of Olive Products from Greece)
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13 pages, 1626 KiB  
Article
Chemometric Study of Fatty Acid Composition of Virgin Olive Oil from Four Widespread Greek Cultivars
by Panagiota-Kyriaki Revelou, Marinos Xagoraris, Athanasia Alexandropoulou, Charalabos D. Kanakis, George K. Papadopoulos, Christos S. Pappas and Petros A. Tarantilis
Molecules 2021, 26(14), 4151; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules26144151 - 08 Jul 2021
Cited by 5 | Viewed by 2903
Abstract
Virgin olive oil (VOO) is one of the key components of the Mediterranean diet owing to the presence of monounsaturated fatty acids and various bioactive compounds. These beneficial traits, which are usually associated with the cultivar genotype, are highlighting the demand of identifying [...] Read more.
Virgin olive oil (VOO) is one of the key components of the Mediterranean diet owing to the presence of monounsaturated fatty acids and various bioactive compounds. These beneficial traits, which are usually associated with the cultivar genotype, are highlighting the demand of identifying characteristics of olive oil that will ensure its authenticity. In this work, the fatty acid (FA) composition of 199 VOO samples from Koroneiki, Megaritiki, Amfissis, and Manaki cultivars was determined and studied by chemometrics. Olive cultivar greatly influenced the FA composition, namely, oleic acid (from 75.36% for Amfissis to 65.81% for Megaritiki) and linoleic acid (from 13.35% for Manaki to 6.70% for Koroneiki). Spearman’s rho correlation coefficients revealed differences and similarities among the olive oil cultivars. The use of the forward stepwise algorithm identified the FAs arachidonic acid, gadoleic acid, linoleic acid, α-linolenic acid, palmitoleic acid, and palmitic acid as the most significant for the differentiation of samples. The application of linear and quadratic cross-validation discriminant analysis resulted in the correct classification of 100.00% and 99.37% of samples, respectively. The findings demonstrated the special characteristics of the VOO samples derived from the four cultivars and their successful botanical differentiation based on FA composition. Full article
(This article belongs to the Special Issue Characterization of Olive Products from Greece)
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15 pages, 292 KiB  
Article
The Potential of Virgin Olive Oil from cv. Chondrolia Chalkidikis and Chalkidiki (Greece) to Bear Health Claims according to the European Legislation
by Aspasia Mastralexi and Maria Z. Tsimidou
Molecules 2021, 26(11), 3184; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules26113184 - 26 May 2021
Cited by 3 | Viewed by 2177
Abstract
The European food legislation authorizes the use of certain health claims based on a scientific basis. This study aimed to evaluate the fatty acid, tocopherol, and polar phenol composition of virgin olive oil (VOO) from cv. Chondrolia Chalkidikis and Chalkidiki regarding the fulfillment [...] Read more.
The European food legislation authorizes the use of certain health claims based on a scientific basis. This study aimed to evaluate the fatty acid, tocopherol, and polar phenol composition of virgin olive oil (VOO) from cv. Chondrolia Chalkidikis and Chalkidiki regarding the fulfillment of official requirements for the health claims of ‘oleic acid’, ‘vitamin E’, and ‘olive oil polyphenols’. The examination of representative industrial VOOs from 15 olive mills of the Chalkidiki regional unit showed that the two cultivars yield oils contained the necessary concentrations of the responsible bioactive compounds. This evidence was further substantiated by a four harvest study whereby olives from different maturity stages were sampled from three olive groves. Oils were extracted at a laboratory scale and examined for their content in the above-mentioned three categories of constituents. Oils produced at industrial scale from olives harvested on the ‘technological optimum’ stage according to the olive grove proprietor were also analyzed. Extra virgin olive oil of the studied cultivars can safely bear the generic claims for ‘oleic acid’ and ‘vitamin E’. The cultivars present great potential regarding the total hydroxytyrosol and tyrosol content of the extracted oil required to attain the third health claim that may be influenced negatively by manufacturing practices. Full article
(This article belongs to the Special Issue Characterization of Olive Products from Greece)
19 pages, 4110 KiB  
Article
Classification of Greek Olive Oils from Different Regions by Machine Learning-Aided Laser-Induced Breakdown Spectroscopy and Absorption Spectroscopy
by Nikolaos Gyftokostas, Eleni Nanou, Dimitrios Stefas, Vasileios Kokkinos, Christos Bouras and Stelios Couris
Molecules 2021, 26(5), 1241; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules26051241 - 25 Feb 2021
Cited by 16 | Viewed by 2715
Abstract
In the present work, the emission and the absorption spectra of numerous Greek olive oil samples and mixtures of them, obtained by two spectroscopic techniques, namely Laser-Induced Breakdown Spectroscopy (LIBS) and Absorption Spectroscopy, and aided by machine learning algorithms, were employed for the [...] Read more.
In the present work, the emission and the absorption spectra of numerous Greek olive oil samples and mixtures of them, obtained by two spectroscopic techniques, namely Laser-Induced Breakdown Spectroscopy (LIBS) and Absorption Spectroscopy, and aided by machine learning algorithms, were employed for the discrimination/classification of olive oils regarding their geographical origin. Both emission and absorption spectra were initially preprocessed by means of Principal Component Analysis (PCA) and were subsequently used for the construction of predictive models, employing Linear Discriminant Analysis (LDA) and Support Vector Machines (SVM). All data analysis methodologies were validated by both “k-fold” cross-validation and external validation methods. In all cases, very high classification accuracies were found, up to 100%. The present results demonstrate the advantages of machine learning implementation for improving the capabilities of these spectroscopic techniques as tools for efficient olive oil quality monitoring and control. Full article
(This article belongs to the Special Issue Characterization of Olive Products from Greece)
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16 pages, 3779 KiB  
Article
A New Definition of the Term “High-Phenolic Olive Oil” Based on Large Scale Statistical Data of Greek Olive Oils Analyzed by qNMR
by Panagiotis Diamantakos, Kostas Ioannidis, Christos Papanikolaou, Annia Tsolakou, Aimilia Rigakou, Eleni Melliou and Prokopios Magiatis
Molecules 2021, 26(4), 1115; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules26041115 - 19 Feb 2021
Cited by 20 | Viewed by 4413
Abstract
In the last few years, a new term, “High-phenolic olive oil”, has appeared in scientific literature and in the market. However, there is no available definition of that term regarding the concentration limits of the phenolic ingredients of olive oil. For this purpose, [...] Read more.
In the last few years, a new term, “High-phenolic olive oil”, has appeared in scientific literature and in the market. However, there is no available definition of that term regarding the concentration limits of the phenolic ingredients of olive oil. For this purpose, we performed a large-scale screening and statistical evaluation of 5764 olive oil samples from Greece coming from >30 varieties for an eleven-year period with precisely measured phenolic content by qNMR. Although there is a large variation among the different cultivars, the mean concentration of total phenolic content was 483 mg/kg. The maximum concentration recorded in Greece reached 4003 mg/kg. We also observed a statistically significant correlation of the phenolic content with the harvest period and we also identified varieties affording olive oils with higher phenolic content. In addition, we performed a study of phenolic content loss during usual storage and we found an average loss of 46% in 12 months. We propose that the term high-phenolic should be used for olive oils with phenolic content > 500 mg/kg that will be able to retain the health claim limit (250 mg/kg) for at least 12 months after bottling. The term exceptionally high phenolic olive oil should be used for olive oil with phenolic content > 1200 mg/kg (top 5%). Full article
(This article belongs to the Special Issue Characterization of Olive Products from Greece)
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13 pages, 1091 KiB  
Article
Laminarin Induces Defense Responses and Efficiently Controls Olive Leaf Spot Disease in Olive
by George T. Tziros, Anastasios Samaras and George S. Karaoglanidis
Molecules 2021, 26(4), 1043; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules26041043 - 17 Feb 2021
Cited by 12 | Viewed by 3903
Abstract
Olive leaf spot (OLS) caused by Fusicladiumoleagineum is mainly controlled using copper fungicides. However, the replacement of copper-based products with eco-friendly alternatives is a priority. The use of plant resistance-inducers (PRIs) or biological control agents (BCAs) could contribute in this direction. In [...] Read more.
Olive leaf spot (OLS) caused by Fusicladiumoleagineum is mainly controlled using copper fungicides. However, the replacement of copper-based products with eco-friendly alternatives is a priority. The use of plant resistance-inducers (PRIs) or biological control agents (BCAs) could contribute in this direction. In this study we investigated the potential use of three PRIs (laminarin, acibenzolar-S-methyl, harpin) and a BCA (Bacillus amyloliquefaciens FZB24) for the management of OLS. The tested products provided control efficacy higher than 68%. In most cases, dual applications provided higher (p < 0.05) control efficacies compared to that achieved by single applications. The highest control efficacy of 100% was achieved by laminarin. Expression analysis of the selected genes by RT-qPCR revealed different kinetics of induction. In laminarin-treated plants, for most of the tested genes a higher induction rate (p < 0.05) was observed at 3 days post application. Pal, Lox, Cuao and Mpol were the genes with the higher inductions in laminarin-treated and artificially inoculated plants. The results of this study are expected to contribute towards a better understanding of PRIs in olive culture and the optimization of OLS control, while they provide evidence for potential contributions in the reduction of copper accumulation in the environment. Full article
(This article belongs to the Special Issue Characterization of Olive Products from Greece)
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12 pages, 1938 KiB  
Article
Isotopic Traceability (13C and 18O) of Greek Olive Oil
by Petros Karalis, Anastasia Elektra Poutouki, Theodora Nikou, Maria Halabalaki, Charalampos Proestos, Effie Tsakalidou, Sofia Gougoura, George Diamantopoulos, Maria Tassi and Elissavet Dotsika
Molecules 2020, 25(24), 5816; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules25245816 - 09 Dec 2020
Cited by 7 | Viewed by 2526
Abstract
In recent years, isotopic analysis has been proven a valuable tool for the determination of the origin of various materials. In this article, we studied the 18O and 13C isotopic values of 210 olive oil samples that were originated from different [...] Read more.
In recent years, isotopic analysis has been proven a valuable tool for the determination of the origin of various materials. In this article, we studied the 18O and 13C isotopic values of 210 olive oil samples that were originated from different regions in Greece in order to verify how these values are affected by the climate regime. We observed that the δ18O isotopic values range from 19.2 ‰ to 25.2 ‰ and the δ13C values range from −32.7 ‰ to −28.3 ‰. These differences between the olive oils’ isotopic values depended on the regional temperature, the meteoric water, and the distance from the sea. Furthermore, we studied the 13C isotopic values of biophenolic extracts, and we observed that they have same capability to differentiate the geographic origin. Finally, we compared the isotopic values of Greek olive oils with samples from Italy, and we concluded that there is a great dependence of oxygen isotopes on the climatic characteristics of the different geographical areas. Full article
(This article belongs to the Special Issue Characterization of Olive Products from Greece)
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13 pages, 4246 KiB  
Article
Verifying the Geographical Origin and Authenticity of Greek Olive Oils by Means of Optical Spectroscopy and Multivariate Analysis
by Renate Kontzedaki, Emmanouil Orfanakis, Georgia Sofra-Karanti, Katerina Stamataki, Aggelos Philippidis, Aikaterini Zoumi and Michalis Velegrakis
Molecules 2020, 25(18), 4180; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules25184180 - 12 Sep 2020
Cited by 12 | Viewed by 3670
Abstract
Olive oil samples from three different Greek regions (Crete, Peloponnese and Lesvos) were examined by optical spectroscopy in a wide spectral region from ultraviolet to near infrared using absorption, fluorescence and Raman spectroscopies. With the aid of machine learning methods, such as multivariate [...] Read more.
Olive oil samples from three different Greek regions (Crete, Peloponnese and Lesvos) were examined by optical spectroscopy in a wide spectral region from ultraviolet to near infrared using absorption, fluorescence and Raman spectroscopies. With the aid of machine learning methods, such as multivariate partial least squares discriminant analysis, a clear classification of samples originating from the different Greek geographical regions was revealed. Moreover, samples produced in different subareas of Crete and Peloponnese were also well discriminated. Furthermore, mixtures of olive oils from different geographical origins were studied employing partial least squares as a tool to establish a model between the actual and predicted compositions of the mixtures. The results demonstrated that optical spectroscopy combined with multivariate statistical analysis can be used as an emerging innovative alternative to the classical analytical methods for the identification of the origin and authenticity of olive oils. Full article
(This article belongs to the Special Issue Characterization of Olive Products from Greece)
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14 pages, 4078 KiB  
Article
Varietal and Geographical Discrimination of Greek Monovarietal Extra Virgin Olive Oils Based on Squalene, Tocopherol, and Fatty Acid Composition
by Theano Mikrou, Elisavet Pantelidou, Niki Parasyri, Andreas Papaioannou, Maria Kapsokefalou, Chrysavgi Gardeli and Athanasios Mallouchos
Molecules 2020, 25(17), 3818; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules25173818 - 21 Aug 2020
Cited by 23 | Viewed by 2878
Abstract
Extra virgin olive oil (EVOO) is an important component of the Mediterranean diet and a highly priced product. Despite the strict legislation to protect it from fraudulent practices, there is an increasing demand to characterize EVOOs and evaluate their authenticity. For this purpose, [...] Read more.
Extra virgin olive oil (EVOO) is an important component of the Mediterranean diet and a highly priced product. Despite the strict legislation to protect it from fraudulent practices, there is an increasing demand to characterize EVOOs and evaluate their authenticity. For this purpose, 68 monovarietal EVOOs, originating from three regions of Greece (Peloponnese, Crete, and Lesvos) and two local cultivars (Koroneiki and Kolovi), were obtained during the harvesting period of 2018–2019. Fatty acids, squalene, and tocopherols were determined chromatographically according to official methods in order to study the effect of cultivar and geographical origin. Squalene and γ-tocopherol differed significantly amongst the cultivars tested. Koroneiki samples exhibited higher squalene content than Kolovi samples, whereas the opposite was observed for γ-tocopherol. The tocopherol level was highly geographical dependent, with EVOOs from Peloponnese displaying the highest concentration of α-tocopherol, whereas the content of γ-tocopherol was significantly higher in samples from Lesvos. Unsupervised and supervised multivariate analysis resulted in a satisfactory grouping of EVOOs according to cultivar. γ-Tocopherol, squalene, and the majority of fatty acids were the most discriminant variables, with γ-tocopherol, linoleic, linolenic, and gadoleic acid being present at higher levels in samples from the Kolovi cultivar. Koroneiki samples were characterized with higher levels of squalene, palmitic, palmitoleic, and arachidic acid. Full article
(This article belongs to the Special Issue Characterization of Olive Products from Greece)
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22 pages, 4361 KiB  
Article
NMR-Based Metabolic Profiling of Edible Olives—Determination of Quality Parameters
by Stavros Beteinakis, Anastasia Papachristodoulou, Georgia Gogou, Sotirios Katsikis, Emmanuel Mikros and Maria Halabalaki
Molecules 2020, 25(15), 3339; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules25153339 - 23 Jul 2020
Cited by 19 | Viewed by 3813
Abstract
Edible olive drupes (from Olea europaea L.) are a high-value food commodity with an increasing production trend over the past two decades. In an attempt to prevent fraud issues and ensure quality, the International Olive Council (IOC) issued guidelines for their sensory evaluation. [...] Read more.
Edible olive drupes (from Olea europaea L.) are a high-value food commodity with an increasing production trend over the past two decades. In an attempt to prevent fraud issues and ensure quality, the International Olive Council (IOC) issued guidelines for their sensory evaluation. However, certain varieties, geographical origins and processing parameters are omitted. The aim of the present study was the development of a method for the quality assessment of edible olives from the Konservolia, Kalamon and Chalkidikis cultivars from different areas of Greece processed with the Spanish or Greek method. A rapid NMR-based untargeted metabolic profiling method was developed along with multivariate analysis (MVA) and applied for the first time in edible olives’ analysis complemented by the aid of statistical total correlation spectroscopy (STOCSY). Specific biomarkers, related to the classification of olives based on different treatments, cultivars and geographical origin, were identified. STOCSY proved to be a valuable aid towards the assignment of biomarkers, a bottleneck in untargeted metabolomic approaches. Full article
(This article belongs to the Special Issue Characterization of Olive Products from Greece)
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