Determination of secoisolariciresinol, lariciresinol and isolariciresinol in plant foods by high performance liquid chromatography coupled with coulometric electrode array detection.
The paper describes a method for the determination of selected lignans in plant foods. First, samples were submitted to methanolysis resulting in cleavage of ester bonds between lignan glycosides and organic acids. Glycosidic linkages were then broken by enzymatic hydrolysis using cellulase. The released aglycones were separated isocratically (acetonitrile/10 mM sodium acetate buffer, pH 4.8, 225:775, v:v) by reversed phase high performance liquid chromatography (RP-HPLC) and the compounds were detected coulometrically at four electrodes set on potentials between +260 and +330 mV against palladium reference electrodes. The selectivity and sensitivity of the method allowed quantitation of the lignans secoisolariciresinol, lariciresinol and isolariciresinol in various foodstuffs down to the upper ppb-range with recoveries between 44.7 and 97.0%. Unidentified peaks displaying similar current-voltage curves (CVCs) as the investigated lignans indicated the presence of further possible lignan representatives. In addition, investigation of various foodstuffs involving enzymatic hydrolysis with and without preceding methanolysis showed that the degree of esterification of lignans in plant foods is species dependent.
Schwartz
Heidi
H
Department of Analytical Chemistry and Food Chemistry, Faculty of Chemistry, University of Vienna, Waehringer Strasse 38, A-1090 Vienna, Austria.
Sontag
Gerhard
G
D002072:Butylene Glycols / Q000032:analysis* / Q000302:isolation & purification; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods; D004566:Electrodes; D005663:Furans / Q000032:analysis* / Q000302:isolation & purification; D006868:Hydrolysis; D017705:Lignans / Q000032:analysis* / Q000302:isolation & purification; D008031:Lignin / Q000032:analysis* / Q000302:isolation & purification; D015394:Molecular Structure; D009284:Naphthols / Q000032:analysis* / Q000302:isolation & purification; D010945:Plants, Edible / Q000737:chemistry*; D015203:Reproducibility of Results
D002072:Butylene Glycols; D005663:Furans; D017705:Lignans; D009284:Naphthols; C060284:isolariciresinol; C060282:lariciresinol; D008031:Lignin; C060283:secoisolariciresinol