title: Discrimination of geographical origin of lentils (Lens culinaris Medik.) using isotope ratio mass spectrometry combined with chemometrics.
abstract: The aim of this study was to predict the geographic origin of lentils by using isotope ratio mass spectrometry (IRMS) in combination with chemometrics. Lentil samples from two origins, i.e. Italy and Canada, were analysed obtaining the stable isotope ratios of δ(13)C, δ(15)N, δ(2)H, δ(18)O, and δ(34)S. A comparison between median values (U-test) highlighted statistically significant differences (p<0.05) for all isotopic parameters between the lentils produced in these two different geographic areas, except for δ(15)N. Applying principal component analysis, grouping of samples was observed on the basis of origin but with overlapping zones; consequently, two supervised discriminant techniques, i.e. partial least squares discriminant analysis and k-nearest neighbours algorithm were used. Both models showed good performances with external prediction abilities of about 93% demonstrating the suitability of the methods developed. Subsequently, isotopic determinations were also performed on the protein and starch fractions and the relevant results are reported.
authors.affiliation: Dipartimento di Chimica, Università di Bari "Aldo Moro", Via Orabona 4, 70126 Bari, Italy. Electronic address: francesco.longobardi@uniba.it.
authors.forename: F
authors.initials: F
authors.lastname: Longobardi
authors.affiliation: Dipartimento di Chimica, Università di Bari "Aldo Moro", Via Orabona 4, 70126 Bari, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Casiello
authors.affiliation: Dipartimento di Chimica, Università di Bari "Aldo Moro", Via Orabona 4, 70126 Bari, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Cortese
authors.affiliation: IASMA Fondazione Edmund Mach, via Mach 1, 38010 San Michele all'Adige (TN), Italy.
authors.forename: M
authors.initials: M
authors.lastname: Perini
authors.affiliation: IASMA Fondazione Edmund Mach, via Mach 1, 38010 San Michele all'Adige (TN), Italy.
authors.forename: F
authors.initials: F
authors.lastname: Camin
authors.affiliation: Dipartimento di Chimica, Università di Bari "Aldo Moro", Via Orabona 4, 70126 Bari, Italy; Consiglio Nazionale delle Ricerche, Istituto per i Processi Chimico-Fisici (IPCF-CNR), sez. di Bari, Via Orabona 4, 70126 Bari, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Catucci
authors.affiliation: Dipartimento di Chimica, Università di Bari "Aldo Moro", Via Orabona 4, 70126 Bari, Italy; Consiglio Nazionale delle Ricerche, Istituto per i Processi Chimico-Fisici (IPCF-CNR), sez. di Bari, Via Orabona 4, 70126 Bari, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Agostiano
mesh_terms: D002170:Canada; D002247:Carbon Isotopes / Q000032:analysis; D004044:Dietary Proteins / Q000032:analysis; D016002:Discriminant Analysis; D005504:Food Analysis / Q000379:methods*; D005843:Geography; D007558:Italy; D016018:Least-Squares Analysis; D027806:Lens Plant / Q000737:chemistry*; D013058:Mass Spectrometry; D009587:Nitrogen Isotopes / Q000032:analysis; D010103:Oxygen Isotopes / Q000032:analysis; D013213:Starch / Q000032:analysis
chemical_list: D002247:Carbon Isotopes; D004044:Dietary Proteins; D009587:Nitrogen Isotopes; D010103:Oxygen Isotopes; D013213:Starch
keywords: Chemometrics; Geographic origin; Isotope ratio mass spectrometry; Lentils