Φαινολικό αποτύπωμα Ελαιολάδων με βάση το γεωγραφικό υψόμετρο με χρήση LC-QTOF-MS

Σε αυτή την πτυχιακή εργασία, ασχοληθήκαμε με το φαινολικό αποτύπωμα σε εξαιρετικά παρθένα ελαιόλαδα από διάφορες περιοχές της Ελλάδας. Ο στόχος ήταν η ανίχνευση και η ταυτοποίηση τις φαινολικές ενώσεις, η σύγκριση του φαινολικού προφίλ, και η συσχέτιση του φαινολικού προφίλ με το υψόμετρο στο οποίο καλλιεργήθηκε η ελιά. Η πειραματική μέθοδος που χρησιμοποιήθηκε ήταν RP-UHPLC-ESI-QTOF-MS/MS με αρνητικό ιοντισμό. Χρησιμοποιήθηκαν οι τεχνικές στοχευμένης και "ύποπτης" σάρωσης, με τη χρήση λίστας που περιείχε φαινολικές ενώσεις που βρέθηκαν σε κάποια όργανα του ελαιοδέντρου. Έτσι, αναλύθηκαν 39 δείγματα από διάφορες περιοχές από το νησί της Λέσβου. Κατηγοριοποιήθηκαν τα δείγματα σε 3 κατηγορίες, ορεινά, ημιορεινά και πεδινά, έτσι να γίνει σύγκριση του φαινολικού προφίλ σε διαφορετικά υψόμετρα.In this paper, we examined the phenolic footprint in extra virgin olive oils from various regions of Greece. The aim was to detect and identify the phenolic compounds in olive oil, to compare the phenolic profiles, and to correlate the phenolic profile with the altitude at which the olive tree was cultivated. The experimental method we used was RP-UHPLC-ESI-QTOF-MS/MS with negative ionization. The techniques were target and non-target screening, using a list with phenolic compounds found in some organs of the olive tree. Using this method, we analyzed 39 samples from various regions from the island of Lesvos. We categorized each sample in 3 different categories, mountainous, semi-mountainous and lowlands to make comparing the phenolic profiles at each altitude possible

Thorough investigation of the phenolic profile of reputable Greek honey varieties:varietal discrimination and floral markers identification using liquid chromatography–high-resolution mass spectrometry

Honey is a highly consumed commodity due to its potential health benefits upon certain consumption, resulting in a high market price. This fact indicates the need to protect honey from fraudulent acts by delivering comprehensive analytical methodologies. In this study, targeted, suspect and non-targeted metabolomic workflows were applied to identify botanical origin markers of Greek honey. Blossom honey samples (n = 62) and the unifloral fir (n = 10), oak (n = 24), pine (n = 39) and thyme (n = 34) honeys were analyzed using an ultra-high-performance liquid chromatography hybrid quadrupole time-of-flight mass spectrometry (UHPLC-q-TOF-MS) system. Several potential authenticity markers were revealed from the application of different metabolomic workflows. In detail, based on quantitative targeted analysis, three blossom honey markers were found, namely, galangin, pinocembrin and chrysin, while gallic acid concentration was found to be significantly higher in oak honey. Using suspect screening workflow, 12 additional bioactive compounds were identified and semi-quantified, achieving comprehensive metabolomic honey characterization. Lastly, by combining non-targeted screening with advanced chemometrics, it was possible to discriminate thyme from blossom honey and develop binary discriminatory models with high predictive power. In conclusion, a holistic approach to assessing the botanical origin of Greek honey is presented, highlighting the complementarity of the three applied metabolomic approaches

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

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

Ανάπτυξη και επικύρωση μεθόδου προσδριορισμού τοκοφερολών, χρωστικών και σκουαλενίου σε ελαιόλαδο με HPLC-DAD

Στην παρούσα μεταπτυχιακή εργασία διπλώματος ειδίκευσης έγινε ανάπτυξη, βελτιστοποίηση και επικύρωση μίας μεθόδου ταυτόχρονου προσδιορισμού τοκοφερολών, χρωστικών και σκουαλενίου σε δείγματα εξαιρετικά παρθένου ελαιόλαδου. Στην συνέχεια, έγινε εφαρμογή της μεθόδου σε δείγματα ελαιόλαδου από την Περιφέρεια Βορείου Αιγαίου. Η αξιολόγηση των αποτελεσμάτων έγινε με χρήση στατιστικής, με σκοπό την κατανόηση και συσχέτιση των παραμέτρων καλλιέργειας και ελαιοποίησης με το τελικό προϊόν, έτσι ώστε να προκύψουν χρήσιμες πληροφορίες για τις συγκεντρώσεις των χημικών αυτών ουσιών στο ελαιόλαδο. Ακόμα, αναφέρονται τα συμπεράσματα που προέκυψαν από την ανάπτυξη της μεθόδου, αλλά και από την συσχέτιση των παραμέτρων που ελέγχθηκαν. Η ποικιλία του ελαιόδεντρου, το νησί καλλιέργειας, το επίπεδο ωρίμανσης του καρπού καθώς και η προσθήκη νερού κατά την μάλαξη, είναι παράμετροι που επιδρούν θετικά ή αρνητικά στις συγκεντρώσεις των ουσιών αυτών στο τελικό προϊόν.In this thesis, an analytical method was developed, optimized and validated for the simultaneous determination of tocopherols, pigments and squalene in samples of extra virgin olive oil. The method was applied to extra virgin olive oil samples from the North Aegean Region. The evaluation of the results was carried out using statistics to understand and correlate the cultivation and oil extraction parameters, in order to obtain useful information on the concentrations of these compounds in olive oil. In addition, the conclusions from the development of the method, as well as the correlation of the parameters checked, are reported. The variety of the olive tree, the island of origin, the level of ripening of the fruit and the addition of water during the malaxation, are parameters that influence positively or negatively the concentrations of these substances in the final product

Performance of RDBMS-WWW Interfaces under Heavy Workload

The WWW is currently considered as the most promising and rapidly evolving software platform for the deployment of applications in wide area networks as well as enterprise intranets. Interfacing legacy systems like RDBMS to the WWW has become a very important issue to the computing industry. We discuss the efficiency of RDBMS gateways throughout periods of increased workload. We present a client/server architecture aiming to diminish overheads encountered in conventional gateways. The performance gain is assessed through a series of measurements. Alternative architectures were subject to the same measurements to assess the performance achieved by technologies like ODBC, JDBC, Dynamic SQL, ISAPI, NSAPI and CORBA

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

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

Development of Analytical Strategies for the Determination of Olive Fruit Bioactive Compounds Using UPLC-HRMS and HPLC-DAD. Chemical Characterization of <i>Kolovi</i> Lesvos Variety as a Case Study

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

Geographical Characterization of Olive Oils from the North Aegean Region Based on the Analysis of Biophenols with UHPLC-QTOF-MS

Olive oil is famous due to the nutritional properties and beneficial health effects. The exceptional properties of virgin (VOO) and extra virgin olive oil (EVOO) are credited to the bioactive constituents of their polar fraction, the phenolic compounds. The concentration and composition of biophenols can be influenced by the geographical origin, the cultivar, as well as several agronomic and technological parameters. In this study, an ultra-high-performance liquid chromatography coupled to quadrupole-time of flight tandem mass spectrometry (UHPLC-QTOF-MS) method was used to determine biophenols in Greek EVOOs from five islands originating from the North Aegean Region (Chios, Fournoi, Ikaria, Lesvos, and Samos) through target and suspect screening. In total, 14 suspect and 5 target compounds were determined in the analyzed EVOOs. The quantitative and semiquantitative results were compared to investigate discriminations between different regions. Significant differences were found between the islands based on the overall phenolic content and the concentration levels of individual compounds, as well. In the case of Lesvos, the territory was separated in subdivisions (zones), and each zone was studied individually