title: Discrimination of conventional and organic white cabbage from a long-term field trial study using untargeted LC-MS-based metabolomics.
abstract: The influence of organic and conventional farming practices on the content of single nutrients in plants is disputed in the scientific literature. Here, large-scale untargeted LC-MS-based metabolomics was used to compare the composition of white cabbage from organic and conventional agriculture, measuring 1,600 compounds. Cabbage was sampled in 2 years from one conventional and two organic farming systems in a rigidly controlled long-term field trial in Denmark. Using Orthogonal Projection to Latent Structures-Discriminant Analysis (OPLS-DA), we found that the production system leaves a significant (p = 0.013) imprint in the white cabbage metabolome that is retained between production years. We externally validated this finding by predicting the production system of samples from one year using a classification model built on samples from the other year, with a correct classification in 83 % of cases. Thus, it was concluded that the investigated conventional and organic management practices have a systematic impact on the metabolome of white cabbage. This emphasizes the potential of untargeted metabolomics for authenticity testing of organic plant products.
authors.affiliation: Department of Clinical Science and Education, Karolinska Institutet, Södersjukhuset, 11883, Stockholm, Sweden, axel.mie@ki.se.
authors.forename: Axel
authors.initials: A
authors.lastname: Mie
authors.forename: Kristian Holst
authors.initials: KH
authors.lastname: Laursen
authors.forename: K Magnus
authors.initials: KM
authors.lastname: Åberg
authors.forename: Jenny
authors.initials: J
authors.lastname: Forshed
authors.forename: Anna
authors.initials: A
authors.lastname: Lindahl
authors.forename: Kristian
authors.initials: K
authors.lastname: Thorup-Kristensen
authors.forename: Marie
authors.initials: M
authors.lastname: Olsson
authors.forename: Pia
authors.initials: P
authors.lastname: Knuthsen
authors.forename: Erik Huusfeldt
authors.initials: EH
authors.lastname: Larsen
authors.forename: Søren
authors.initials: S
authors.lastname: Husted
mesh_terms: D000383:Agriculture / Q000379:methods*; D001937:Brassica / Q000737:chemistry* / Q000254:growth & development; D002853:Chromatography, Liquid; D003718:Denmark; D016002:Discriminant Analysis; D058870:Food, Organic / Q000032:analysis; D013058:Mass Spectrometry; D055432:Metabolomics; D058871:Organic Agriculture / Q000379:methods; D018515:Plant Leaves / Q000737:chemistry / Q000254:growth & development