title: Traceability of different apple varieties by multivariate analysis of isotope ratio mass spectrometry data.
abstract: BACKGROUND
  The awareness of customers of the origin of foods has become an important issue. The growing demand for foods that are healthy, safe and of high quality has increased the need for traceability and clear labelling. Thus, this study investigates the capability of C and N stable isotope ratios to determine the geographical origin of several apple varieties grown in northern Italy.
  
  
  METHODS
  Four apple varieties (Cripps Pink, Gala, Golden Delicious, Granny Smith) have been sampled in orchards located in the Districts of Bolzano, Ferrara, Verona and Udine (northern Italy). Carbon (δ(13) C) and nitrogen (δ(15) N) isotope values of the whole apple fruits and three sub-fractions (peel, pulp and seed) have been determined simultaneously by isotope ratio mass spectrometry.
  
  
  RESULTS
  The δ(13) C and δ(15) N values of apples and apple sub-fractions, such as peel, seed and pulp, were significantly affected by the geographical origin and the fruit variety. The four varieties could be distinguished to a certain extent only within each district. A 99% correct identification of the samples according to their origin was, however, achieved by cross validation with the 'leave-one-out' method.
  
  
  CONCLUSIONS
  This study proves the potential of stable isotopes to discriminate the geographical origin of apples grown in orchards located only a few hundreds of kilometres apart. Stable isotopes were also able to discriminate different apple varieties, although only within small geographical areas.
authors.affiliation: Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100, Bolzano, Italy.
authors.forename: Tanja
authors.initials: T
authors.lastname: Mimmo
authors.affiliation: Food Quality and Nutrition Department, Research and Innovation Centre, Fondazione Edmund Mach, Via Mach 1, 38010, Trento, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Camin
authors.affiliation: Food Quality and Nutrition Department, Research and Innovation Centre, Fondazione Edmund Mach, Via Mach 1, 38010, Trento, Italy.
authors.forename: Luana
authors.initials: L
authors.lastname: Bontempo
authors.affiliation: Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100, Bolzano, Italy.
authors.forename: Calogero
authors.initials: C
authors.lastname: Capici
authors.affiliation: Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100, Bolzano, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Tagliavini
authors.affiliation: Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100, Bolzano, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Cesco
authors.affiliation: Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100, Bolzano, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Scampicchio
mesh_terms: D002247:Carbon Isotopes / Q000032:analysis; D016002:Discriminant Analysis; D005638:Fruit / Q000737:chemistry / Q000145:classification; D027845:Malus / Q000737:chemistry* / Q000145:classification; D013058:Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D015999:Multivariate Analysis; D009587:Nitrogen Isotopes / Q000032:analysis
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes