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Home    Ταξινόμηση ελαιολάδων διαφόρων κατηγοριών ποιότητας με τη φασματοσκοπία NMR και τη χημειομετρία. Ανίχνευση νοθείας έξτρα παρθένου ελαιόλαδου με ελαιόλαδα κατώτερης ποιότητας  

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Identifier uch.chemistry.msc//2004fragkaki
Title Ταξινόμηση ελαιολάδων διαφόρων κατηγοριών ποιότητας με τη φασματοσκοπία NMR και τη χημειομετρία. Ανίχνευση νοθείας έξτρα παρθένου ελαιόλαδου με ελαιόλαδα κατώτερης ποιότητας
Creator Fragkaki, Georgia
Abstract High field 1H NMR (500 MHz) and 31P NMR (202.2 MHz) spectroscopy was applied to the analysis of 76 samples from four grades of olive oils, namely 34 extra virgin olive oils from various regions of Greece, and from four different olive varieties, 13 samples of refined olive oils, 14 samples of lampante olive oils, and 15 samples of crude olive-pomace oil. Classification of the four grades of olive oils was achieved by two multivariate statistical methods applied to eight variables, the latter being determined upon analysis of the respective 1H NMR and 31P NMR spectra, and selected on the basis of the Fisher F ratios. The Hierarchical clustering (HCA) statistical procedure applied without any a priori hypothesis was able to group three out of four olive oil groups. Subsequent application of Discriminant Analysis to the eight selected variables of oils allowed the grouping of 76 samples according to their quality with only one error. The reliability of the model to classify the oils was assessed by its ability to correctly classify unknown samples. Different artificial mixtures of extra virgin olive-refined olive, extra virgin olive-lampante olive, and extra virgin olive-olive-pomace oils were prepared and analyzed by 1H NMR and 31P NMR spectroscopy. Subsequent Discriminant Analysis of the data allowed detection of adulteration as low as 1% w/w for crude olive-pomace oils, 3% w/w for refined olive oil, and 3% w/w for lampante olive oil. Further application of the classification/prediction model allowed the estimation of the % concentration of refined olive oil in six commercial pure olive oils purchased from supermarkets.
Subject 1H NMR and 31P NMR spectroscopy, extra virgin olive oil, refined olive oil, lampante olive oil, olive-pomace oil, hierarchical cluster analysis, discriminant analysis, adulteration of olive oil, έξτρα παρθένο ελαιόλαδο, ραφιναρισμένο ελαιόλαδο, ελαιόλαδο λαμπάντε, πυρηνέλαιο, ανάλυση συστάδων, ανάλυση διακριτότητας, νοθεία έξτρα παρθένου ελαιολάδου
Issue date 2004-07-01
Date available 2004-08-03
Collection   School/Department--School of Sciences and Engineering--Department of Chemistry--Post-graduate theses
  Type of Work--Post-graduate theses
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