title: Effect of nutrient-based fertilisers of olive trees on olive oil quality.
abstract: BACKGROUND
  This work was conducted to determine the effects of two nutrient-based fertilisers on the general physicochemical characteristics (including free fatty acid content, peroxide value and UV spectrophotometric characteristics), fatty acid profile, total phenols, o-diphenols and phytosterol composition of olive oil. Foliar applications were carried out in two successive years and included four treatments: TC (control, without foliar nutrition), T1 (rich in nitrogen, applied at the start of vegetation, 10 days later and 20 days later), T2 (rich in boron, magnesium, sulfur and manganese, applied at the beginning of flowering and 10 days later) and T3 (T1+T2). At the end of the experiment (after 2 years), oils were extracted and analysed.
  
  
  RESULTS
  No effect was found on either general physicochemical characteristics or fatty acid composition. Foliar fertilisation caused a significant decrease in both polyphenol and o-diphenol contents. Total sterol content was unaffected by foliar fertilisation. However, the phytosterol composition of the oil, particularly its β-sitosterol level, was markedly improved after foliar nutrient application. Principal component analysis of the phytosterol composition showed discrimination between the control oil and the oils from T1, T2 and T3 treatments.
  
  
  CONCLUSIONS
  The results of this study extend the current knowledge of such cross-talk between plant nutrition and quality of oil.
authors: Laboratoire de Biochimie, USCR Spectrométrie de Masse, UR Nutrition et Désordres Métaboliques, Faculté de Médecine, Université de Monastir, 5019, Monastir, Tunisia. meriem_tekaya@yahoo.fr
authors: Meriem
authors: M
authors: Tekaya
authors: Beligh
authors: B
authors: Mechri
authors: Amani
authors: A
authors: Bchir
authors: Faouzi
authors: F
authors: Attia
authors: Hechmi
authors: H
authors: Cheheb
authors: Mohamed
authors: M
authors: Daassa
authors: Mohamed
authors: M
authors: Hammami
mesh_terms: D005227:Fatty Acids / Q000737:chemistry; D005308:Fertilizers; D031658:Olea / Q000502:physiology*; D000069463:Olive Oil; D010636:Phenols / Q000737:chemistry; D010840:Phytosterols / Q000737:chemistry; D010938:Plant Oils / Q000737:chemistry* / Q000592:standards*
chemical_list: D005227:Fatty Acids; D005308:Fertilizers; D000069463:Olive Oil; D010636:Phenols; D010840:Phytosterols; D010938:Plant Oils