title: Minor polar compounds in extra virgin olive oil: correlation between HPLC-DAD-MS and the Folin-Ciocalteu spectrophotometric method.
abstract: Minor polar compounds of 88 extra virgin olive oils were analyzed by HPLC-DAD-MS (high-performance liquid chromatography-diode array detector-mass spectrometry) and by the Folin-Ciocalteu (FC) spectrophotometric method, to validate and evaluate, for olive oils, the linear association between FC and HPLC data. The Pearson correlation coefficients were calculated between HPLC and FC results. The highest, positive R were related with deacetoxyoleuropein aglycone (R = 0.93) and oleuropein aglycone (R = 0.93) as single compounds and with the sum of orthodiphenols (R = 0.94) and the sum of all compounds (R = 0.95), showing that both estimations of total phenols content are reliably correlated, regardless for the absolute contents and are independent of the relative composition of the phenolic fraction. On the other hand the HPLC quantifications of apigenin and lignans showed no significant correlation with FC. These results, supported also by principal component analysis, may suggest caution about the interpretation of FC results to compare olive oils with very different phenolic profiles.
authors.affiliation: Department of Statistic, Informatics and Applications ″G. Parenti″ (DiSIA), University of Florence , Viale Morgagni, 59 - 50134 Firenze (FI), Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Alessandri
authors.forename: Francesca
authors.initials: F
authors.lastname: Ieri
authors.forename: Annalisa
authors.initials: A
authors.lastname: Romani
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005419:Flavonoids / Q000032:analysis; D039823:Iridoids / Q000032:analysis; D017705:Lignans / Q000032:analysis; D013058:Mass Spectrometry; D008982:Molybdenum; D000069463:Olive Oil; D010636:Phenols / Q000032:analysis*; D010938:Plant Oils / Q000737:chemistry*; D013053:Spectrophotometry / Q000379:methods*; D017973:Tungsten Compounds
chemical_list: D005419:Flavonoids; C029556:Folin's phenol reagent; D039823:Iridoids; D017705:Lignans; D000069463:Olive Oil; D010636:Phenols; D010938:Plant Oils; D017973:Tungsten Compounds; D008982:Molybdenum