title: Differentiation of Organically and Conventionally Grown Tomatoes by Chemometric Analysis of Combined Data from Proton Nuclear Magnetic Resonance and Mid-infrared Spectroscopy and Stable Isotope Analysis.
abstract: Because the basic suitability of proton nuclear magnetic resonance spectroscopy ((1)H NMR) to differentiate organic versus conventional tomatoes was recently proven, the approach to optimize (1)H NMR classification models (comprising overall 205 authentic tomato samples) by including additional data of isotope ratio mass spectrometry (IRMS, δ(13)C, δ(15)N, and δ(18)O) and mid-infrared (MIR) spectroscopy was assessed. Both individual and combined analytical methods ((1)H NMR + MIR, (1)H NMR + IRMS, MIR + IRMS, and (1)H NMR + MIR + IRMS) were examined using principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), linear discriminant analysis (LDA), and common components and specific weight analysis (ComDim). With regard to classification abilities, fused data of (1)H NMR + MIR + IRMS yielded better validation results (ranging between 95.0 and 100.0%) than individual methods ((1)H NMR, 91.3-100%; MIR, 75.6-91.7%), suggesting that the combined examination of analytical profiles enhances authentication of organically produced tomatoes.
authors.affiliation: Institute of Pharmacy and Food Chemistry, University of Würzburg , Am Hubland, 97074 Würzburg, Germany.|Bavarian Health and Food Safety Authority , Luitpoldstraße 1, 97082 Würzburg, Germany.
authors.forename: Monika
authors.initials: M
authors.lastname: Hohmann
authors.affiliation: Spectral Service , Emil-Hoffmann-Straße 33, 50996 Cologne, Germany.|Department of Chemistry, Saratov State University , Astrakhanskaya Street 83, 410012 Saratov, Russia.
authors.forename: Yulia
authors.initials: Y
authors.lastname: Monakhova
authors.affiliation: Chemical and Veterinary Investigation Laboratory , Bissierstraße 5, 79114 Freiburg, Germany.
authors.forename: Sarah
authors.initials: S
authors.lastname: Erich
authors.affiliation: Bavarian Health and Food Safety Authority , Luitpoldstraße 1, 97082 Würzburg, Germany.
authors.forename: Norbert
authors.initials: N
authors.lastname: Christoph
authors.affiliation: Bavarian Health and Food Safety Authority , Luitpoldstraße 1, 97082 Würzburg, Germany.
authors.forename: Helmut
authors.initials: H
authors.lastname: Wachter
authors.affiliation: Institute of Pharmacy and Food Chemistry, University of Würzburg , Am Hubland, 97074 Würzburg, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Holzgrabe
mesh_terms: D000383:Agriculture; D002247:Carbon Isotopes / Q000032:analysis; D016002:Discriminant Analysis; D018551:Solanum lycopersicum / Q000737:chemistry* / Q000254:growth & development; D009587:Nitrogen Isotopes / Q000032:analysis; D058871:Organic Agriculture; D010103:Oxygen Isotopes / Q000032:analysis; D066244:Proton Magnetic Resonance Spectroscopy / Q000379:methods*; D013055:Spectrophotometry, Infrared / Q000379:methods*
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D010103:Oxygen Isotopes
keywords: 1H NMR; IRMS; MIR; chemometrics; data fusion; organic tomatoes