title: Virgin olive oil quality of hedgerow 'Arbequina' olive trees under deficit irrigation.
abstract: BACKGROUND
  Regulated deficit irrigation (RDI) is used in hedgerow olive orchards to achieve a sustainable balance between water savings, tree vigor and oil production. Its effects on the presence of compounds responsible for the taste of the oil and its nutritional value are controversial. The present 3-year study was conducted in an 'Arbequina' orchard (1667 trees ha-1) under a full irrigation (FI) treatment (470.1 mm year-1of water) and two RDI treatments scaled to replace 60% and 30%, respectively, of FI. The quality parameters, antioxidant contents and volatiles of the extracted virgin olive oil (VOO) were analyzed.
  
  
  RESULTS
  In general, oils from the 30% RDI treatment had higher contents of pigments and phenolic compounds, a higher oleic/linoleic ratio and the highest oxidative stability, despite their lower tocopherol content. FI oils showed higher (E)-2-hexenal, 1-penten-3-one, ocimene, E-2-pentenal and pentene dimer contents than 30RDI oils, but lower contents of (E)-2-pentenol and volatile esters.
  
  
  CONCLUSIONS
  The results of the present study suggest that a RDI strategy supplying 30% of the total irrigation needs induces an increase in natural antioxidants in VOO. Neither yield, nor the rest of the quality parameters were affected by the reduced irrigation. However, abundant autumn precipitation can over-ride these effects of 30% RDI treatment on oil quality. © 2016 Society of Chemical Industry.
authors.affiliation: Instituto de la Grasa (IG-CSIC) Campus Universidad Pablo de Olavide, Edificio 46, Carretera Sevilla-Utrera km 1, 41013 Sevilla, Spain.
authors.forename: José M
authors.initials: JM
authors.lastname: García
authors.affiliation: Departamento de Ciencias Agroforestales, ETSIA, Universidad de Sevilla, Carretera de Utrera km 1, 41013 Sevilla, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Morales-Sillero
authors.affiliation: Instituto de la Grasa (IG-CSIC) Campus Universidad Pablo de Olavide, Edificio 46, Carretera Sevilla-Utrera km 1, 41013 Sevilla, Spain.
authors.forename: Ana G
authors.initials: AG
authors.lastname: Pérez-Rubio
authors.affiliation: Instituto de Recursos Naturales y Agrobiología (IRNAS, CSIC), Avenida de Reina Mercedes, n. 10, 41012 Sevilla, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Diaz-Espejo
authors.affiliation: Instituto de Recursos Naturales y Agrobiología (IRNAS, CSIC), Avenida de Reina Mercedes, n. 10, 41012 Sevilla, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Montero
authors.affiliation: Instituto de Recursos Naturales y Agrobiología (IRNAS, CSIC), Avenida de Reina Mercedes, n. 10, 41012 Sevilla, Spain.
authors.forename: José E
authors.initials: JE
authors.lastname: Fernández
mesh_terms: D057914:Agricultural Irrigation / Q000379:methods*; D000447:Aldehydes / Q000032:analysis / Q000378:metabolism; D000975:Antioxidants / Q000032:analysis / Q000378:metabolism; D003247:Conservation of Natural Resources; D000069599:Crop Production; D018556:Crops, Agricultural / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism; D005062:European Union; D063427:Food Quality; D005638:Fruit / Q000737:chemistry* / Q000254:growth & development* / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009753:Nutritive Value; D031658:Olea / Q000737:chemistry* / Q000254:growth & development* / Q000378:metabolism; D000069463:Olive Oil / Q000032:analysis* / Q000592:standards; D010084:Oxidation-Reduction; D010422:Pentanones / Q000032:analysis / Q000378:metabolism; D010860:Pigments, Biological / Q000032:analysis / Q000096:biosynthesis; D013030:Spain; D024505:Tocopherols / Q000032:analysis / Q000378:metabolism; D015854:Up-Regulation; D055549:Volatile Organic Compounds / Q000032:analysis / Q000378:metabolism
chemical_list: D000447:Aldehydes; D000975:Antioxidants; D000069463:Olive Oil; D010422:Pentanones; D010860:Pigments, Biological; D055549:Volatile Organic Compounds; C051750:2-hexenal; C064599:2-pentenal; C057461:1-pentene-3-one; D024505:Tocopherols
keywords: acidity; natural antioxidants; oxidative alterations; sensory quality; stability; super-high density