title: Combined chemometric analysis of (1)H NMR, (13)C NMR and stable isotope data to differentiate organic and conventional milk.
abstract: The increased sales of organically produced food create a strong need for analytical methods, which could authenticate organic and conventional products. Combined chemometric analysis of (1)H NMR-, (13)C NMR-spectroscopy data, stable-isotope data (IRMS) and α-linolenic acid content (gas chromatography) was used to differentiate organic and conventional milk. In total 85 raw, pasteurized and ultra-heat treated (UHT) milk samples (52 organic and 33 conventional) were collected between August 2013 and May 2014. The carbon isotope ratios of milk protein and milk fat as well as the α-linolenic acid content of these samples were determined. Additionally, the milk fat was analyzed by (1)H and (13)C NMR spectroscopy. The chemometric analysis of combined data (IRMS, GC, NMR) resulted in more precise authentication of German raw and retail milk with a considerably increased classification rate of 95% compared to 81% for NMR and 90% for IRMS using linear discriminate analysis.
authors.affiliation: Chemisches und Veterinäruntersuchungsamt (CVUA) Freiburg, Bissierstraße 5, 79114 Freiburg, Germany. Electronic address: Sarah.Erich@cvuafr.bwl.de.
authors.forename: Sarah
authors.initials: S
authors.lastname: Erich
authors.affiliation: Chemisches und Veterinäruntersuchungsamt (CVUA) Freiburg, Bissierstraße 5, 79114 Freiburg, Germany. Electronic address: Sandra.Schill@cvuafr.bwl.de.
authors.forename: Sandra
authors.initials: S
authors.lastname: Schill
authors.affiliation: Chemisches und Veterinäruntersuchungsamt (CVUA) Freiburg, Bissierstraße 5, 79114 Freiburg, Germany. Electronic address: Eva.Annweiler@cvuafr.bwl.de.
authors.forename: Eva
authors.initials: E
authors.lastname: Annweiler
authors.affiliation: Chemisches und Veterinäruntersuchungsamt (CVUA) Freiburg, Bissierstraße 5, 79114 Freiburg, Germany. Electronic address: Hans-Ulrich.Waiblinger@cvuafr.bwl.de.
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Waiblinger
authors.affiliation: Chemisches und Veterinäruntersuchungsamt (CVUA) Karlsruhe, Weissenburger Straße 3, 76187 Karlsruhe, Germany. Electronic address: Thomas.Kuballa@cvuaka.bwl.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kuballa
authors.affiliation: Chemisches und Veterinäruntersuchungsamt (CVUA) Karlsruhe, Weissenburger Straße 3, 76187 Karlsruhe, Germany. Electronic address: Dirk.Lachenmeier@cvuaka.bwl.de.
authors.forename: Dirk W
authors.initials: DW
authors.lastname: Lachenmeier
authors.affiliation: Chemisches und Veterinäruntersuchungsamt (CVUA) Karlsruhe, Weissenburger Straße 3, 76187 Karlsruhe, Germany; Bruker Biospin GmbH, Silberstreifen 4, 76287 Rheinstetten, Germany; Spectral Service AG, Emil-Hoffmann-Straße 33, 50996 Cologne, Germany; Institute of Chemistry, Saratov State University, Astrakhanskaya Street 83, 410012 Saratov, Russia. Electronic address: yul-monakhova@mail.ru.
authors.forename: Yulia B
authors.initials: YB
authors.lastname: Monakhova
mesh_terms: D000818:Animals; D002247:Carbon Isotopes / Q000032:analysis*; D002417:Cattle; D058870:Food, Organic / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008892:Milk / Q000737:chemistry*
chemical_list: D002247:Carbon Isotopes
keywords: Chemometrics; Data fusion; Linolenic acid (PubChem CID: 5280934); NMR spectroscopy; Organic milk; Stable isotope-ratio mass spectrometry (IRMS)