Classification of organic and conventional sweet peppers and lettuce using a combination of isotopic and bio-markers with multivariate analysis

Pilar Flores, Alicia López, José Fenoll, Pilar Hellín, Simon Kelly

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24 Citations (Scopus)


In order to verify the authenticity of organic products, multivariate data (δN values, key-metabolites and mineral content) were used to classify organic and conventional peppers and lettuce by means of canonical discriminant analysis. Different origins and types of fertilisers were considered. This is the first paper to look into the influence of biosolarisation, a soil disinfection technique widely used in organic cultivation, on the differentiation between organic and conventional crops. The use of pre-harvest parameters (plant and soil δN and plant weight) allowed 78.8% and 65.4% of pepper and lettuce samples, respectively, to be correctly classified. In pepper, this percentage was reduced (69.2%) when only post-harvest sampling parameters were used to build the classification model. In lettuce, the use of biomarkers significantly improved the model, allowing 90.4% of cases to be correctly classified. This methodology showed a high potential for use as an authenticity control tool for organic cultivation.
Original languageEnglish
Pages (from-to)217-225
Number of pages9
JournalJournal of Food Composition and Analysis
Issue number2
Publication statusPublished - Sep 2013


  • Pepper
  • Bell pepper
  • Sweet pepper
  • Capsicum annuum L. cv. Quito
  • Lettuce
  • Lactuca sativa L. cv. Little Gem Ferro
  • Organic farming practices
  • Horticulture and nutrition
  • Authenticity
  • N-15
  • Sugars
  • Organic acids
  • Phenolic
  • Vitamin C
  • Chlorophyll
  • Food analysis
  • Food composition

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