title: Comparison of polyacetylene content in organically and conventionally grown carrots using a fast ultrasonic liquid extraction method.
abstract: A rapid and sensitive analytical method for quantification of polyacetylenes in carrot roots was developed. The traditional extraction method (stirring) was compared to a new ultrasonic liquid processor (ULP)-based methodology using high-performance liquid chromatography-ultraviolet (HPLC-UV) and mass spectrometry (MS) for identification and quantification of three polyacetylenes. ULP was superior because a significant reduction in extraction time and improved extraction efficiencies were obtained. After optimization, the ULP method showed good selectivity, precision [relative standard deviations (RSDs) of 2.3-3.6%], and recovery (93% of falcarindiol) of the polyacetylenes. The applicability of the method was documented by comparative analyses of carrots grown organically or conventionally in a 2 year field trial study. The average concentrations of falcarindiol, falcarindiol-3-acetate, and falcarinol in year 1 were 222, 30, and 94 mug of falcarindiol equiv/g of dry weight, respectively, and 3-15% lower in year 2. The concentrations were not significantly influenced by the growth system, but a significant year-year variation was observed for falcarindiol-3-acetate.
authors.affiliation: Department of Food Chemistry, National Food Institute, Technical University of Denmark, Mørkhøj Bygade 19, DK-2860 Søborg, Denmark.
authors.forename: Malene
authors.initials: M
authors.lastname: Søltoft
authors.forename: Morten Rosbjørn
authors.initials: MR
authors.lastname: Eriksen
authors.forename: Anne Wibe Braendholt
authors.initials: AW
authors.lastname: Träger
authors.forename: John
authors.initials: J
authors.lastname: Nielsen
authors.forename: Kristian Holst
authors.initials: KH
authors.lastname: Laursen
authors.forename: Søren
authors.initials: S
authors.lastname: Husted
authors.forename: Ulrich
authors.initials: U
authors.lastname: Halekoh
authors.forename: Pia
authors.initials: P
authors.lastname: Knuthsen
mesh_terms: D000383:Agriculture; D005591:Chemical Fractionation / Q000295:instrumentation / Q000379:methods*; D018552:Daucus carota / Q000737:chemistry*; D058870:Food, Organic / Q000032:analysis*; D010936:Plant Extracts / Q000032:analysis / Q000302:isolation & purification*; D018517:Plant Roots / Q000737:chemistry; D053279:Polyynes / Q000032:analysis / Q000302:isolation & purification*; D014465:Ultrasonics
chemical_list: D010936:Plant Extracts; D053279:Polyynes