title: Isotope ratio mass spectrometry in combination with chemometrics for characterization of geographical origin and agronomic practices of table grape.
abstract: BACKGROUND
  Although table grape is one of the most cultivated and consumed fruits worldwide, no study has been reported on its geographical origin or agronomic practice based on stable isotope ratios. This study aimed to evaluate the usefulness of isotopic ratios (i.e.2H/1H,13C/12C,15N/14N and18O/16O) as possible markers to discriminate the agronomic practice (conventional versus organic farming) and provenance of table grape.
  
  
  RESULTS
  In order to quantitatively evaluate which of the isotopic variables were more discriminating, a t test was carried out, in light of which only δ13C and δ18O provided statistically significant differences (P ≤ 0.05) for the discrimination of geographical origin and farming method. Principal component analysis (PCA) showed no good separation of samples differing in geographical area and agronomic practice; thus, for classification purposes, supervised approaches were carried out. In particular, general discriminant analysis (GDA) was used, resulting in prediction abilities of 75.0 and 92.2% for the discrimination of farming method and origin respectively.
  
  
  CONCLUSIONS
  The present findings suggest that stable isotopes (i.e. δ18O, δ2H and δ13C) combined with chemometrics can be successfully applied to discriminate the provenance of table grape. However, the use of bulk nitrogen isotopes was not effective for farming method discrimination. © 2016 Society of Chemical Industry.
authors.affiliation: Dipartimento di Chimica, Università di Bari 'Aldo Moro', Via Orabona 4, I-70126, Bari, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Longobardi
authors.affiliation: Dipartimento di Chimica, Università di Bari 'Aldo Moro', Via Orabona 4, I-70126, Bari, Italy.
authors.forename: Grazia
authors.initials: G
authors.lastname: Casiello
authors.affiliation: Dipartimento di Chimica, Università di Bari 'Aldo Moro', Via Orabona 4, I-70126, Bari, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Centonze
authors.affiliation: Dipartimento di Chimica, Università di Bari 'Aldo Moro', Via Orabona 4, I-70126, Bari, Italy.|Consiglio Nazionale delle Ricerche, Istituto per i Processi Chimico-Fisici (IPCF-CNR), sez. di Bari, Via Orabona 4, I-70126, Bari, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Catucci
authors.affiliation: Dipartimento di Chimica, Università di Bari 'Aldo Moro', Via Orabona 4, I-70126, Bari, Italy.|Consiglio Nazionale delle Ricerche, Istituto per i Processi Chimico-Fisici (IPCF-CNR), sez. di Bari, Via Orabona 4, I-70126, Bari, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Agostiano
mesh_terms: D002247:Carbon Isotopes / Q000032:analysis; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D016002:Discriminant Analysis; D005638:Fruit / Q000737:chemistry* / Q000145:classification; D005843:Geography; D013058:Mass Spectrometry / Q000379:methods*; D009587:Nitrogen Isotopes / Q000032:analysis; D010103:Oxygen Isotopes / Q000032:analysis; D027843:Vitis / Q000737:chemistry* / Q000145:classification
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D010103:Oxygen Isotopes
keywords: agronomic practices; chemometrics; geographical origin; isotope ratio mass spectrometry; table grape