title: Oil quality parameters and quantitative measurement of major secoiridoid derivatives in Neb Jmel olive oil from various Tunisian origins using qNMR.
abstract: BACKGROUND
  Olive oil contains compounds with interesting biological activities which are influenced by the cultivar, the geographic origin and other factors. The aims of this work were to (1) investigate these factors in Neb Jmel olive oil from various Tunisian origins; (2) determine the influence of geographic conditions on phenolic composition of Neb Jmel olive oil and consequently on the antioxidant compounds; and (3) verify whether oils could be discriminated based on geographical origin.
  
  
  RESULTS
  The characterisation of extra-virgin Neb Jmel olive oil produced in its original location has been conducted. Owing to the effect of the genotype and environmental, agronomic and technological factors on the chemical composition of olive oil and its quality, all studied olives were collected at the same season, and their oil obtained under the same processing technique. Many analyses were carried out to characterise the different olive oils: free acidity, peroxide value, fatty acid composition, Rancimat assay, pigments content and phenolic compounds by (1) H NMR. A recently developed method for the direct measurement of the oleocanthal and oleacein levels in olive oil by quantitative (1) H NMR was applied. The method was applied to the study of four Neb Jmel olive oils samples, and a broad variation of concentrations of all four secoiridoids was recorded. The concentration of each ranged from 55 to 529 mg kg(-1) and the sum of the four major secoiridoids (known as D3) ranged from 436 to 1063 mg kg(-1) .
  
  
  CONCLUSIONS
  The quantification of major phenolic compounds of olive oil by NMR indicated that environmental conditions influence the production of qualitative phenolic fractions. All these compounds can be used as base 'markers' to characterise and differentiate these olive oil on geographic origin. © 2016 Society of Chemical Industry.
authors: Laboratoire d'Electrochimie et Environnement, Ecole Nationale d'Ingénieurs de Sfax BP «1173» 3038, Université de Sfax, Sfax, Tunisia.
authors: Amir
authors: A
authors: Ben Mansour
authors: Laboratoire d'Electrochimie et Environnement, Ecole Nationale d'Ingénieurs de Sfax BP «1173» 3038, Université de Sfax, Sfax, Tunisia.
authors: Boutheina
authors: B
authors: Gargouri
authors: Department of Pharmacognosy and Natural Products Chemistry, Faculty of Pharmacy, University of Athens, Panepistimiopolis, Zografou, 15771 Athens, Greece.
authors: Eleni
authors: E
authors: Melliou
authors: Department of Pharmacognosy and Natural Products Chemistry, Faculty of Pharmacy, University of Athens, Panepistimiopolis, Zografou, 15771 Athens, Greece.
authors: Prokopios
authors: P
authors: Magiatis
authors: Laboratoire d'Electrochimie et Environnement, Ecole Nationale d'Ingénieurs de Sfax BP «1173» 3038, Université de Sfax, Sfax, Tunisia.|Institut Supérieur de Biotechnologie de Sfax, Université de Sfax, BP «1175» 3038, Sfax, Tunisia.
authors: Mohamed
authors: M
authors: Bouaziz
mesh_terms: D000447:Aldehydes / Q000032:analysis / Q000378:metabolism; D000465:Algorithms; D000975:Antioxidants / Q000032:analysis / Q000378:metabolism; D015415:Biomarkers / Q000032:analysis; D000081004:Cyclopentane Monoterpenes; D003889:Desert Climate; D005227:Fatty Acids / Q000032:analysis / Q000096:biosynthesis; D005513:Food Inspection; D063427:Food Quality; D005638:Fruit / Q000737:chemistry* / Q000254:growth & development / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D039823:Iridoids / Q000032:analysis* / Q000378:metabolism; D008054:Lipid Peroxides / Q000032:analysis / Q000378:metabolism; D019906:Nuclear Magnetic Resonance, Biomolecular; D031658:Olea / Q000737:chemistry* / Q000254:growth & development / Q000378:metabolism; D000069463:Olive Oil / Q000737:chemistry* / Q000145:classification; D010636:Phenols / Q000032:analysis* / Q000378:metabolism; D010860:Pigments, Biological / Q000032:analysis / Q000096:biosynthesis; D013045:Species Specificity; D014416:Tunisia
chemical_list: D000447:Aldehydes; D000975:Antioxidants; D015415:Biomarkers; D000081004:Cyclopentane Monoterpenes; D005227:Fatty Acids; D039823:Iridoids; D008054:Lipid Peroxides; D000069463:Olive Oil; D010636:Phenols; D010860:Pigments, Biological; C578055:oleacein; C503534:oleocanthal
keywords: Neb Jmel cultivar; growing area; oil quality; qNMR; secoiridoid derivatives