title: Irrigation effects on quality, phenolic composition, and selected volatiles of virgin olive oils cv. Leccino.
abstract: Field-grown olive trees (Olea europaea L. cv. Leccino) were used over two growing seasons to determine the effect of deficit irrigation regimes on virgin olive oil (VOO) quality. Drip irrigation was managed to maintain a predawn leaf water potential (PLWP): (a) higher than -1.1 MPa (full irrigation: FI); (b) between -1.0 and -3.3 MPa (deficit irrigation: DI); (c) higher than -4.2 MPa (severe deficit irrigation: SI). The fruit yield and oil yield of DI trees were over 90% of those of FI treatments in both years, respectively, whereas yields of SI trees ranged from 61 to 76%. The irrigation regime had minor effects on the free acidity, peroxide value, and fatty acid composition of VOO. The concentrations of phenols and o-diphenols in VOO were negatively correlated with PLWP. The concentrations of the dialdehydic form of decarboxymethyl elenolic acid linked to (3,4-dihydroxyphenyl)ethanol (3,4-DHPEA-EDA), the isomer of the oleuropein aglycon (3,4-DHPEA-EA), and the dialdehydic form of decarboxymethyl elenolic acid linked to (p-hydroxyphenyl)ethanol (p-HPEA-EDA) were lower in FI than in SI treatments. The concentrations of lignans (+)-1-acetoxipinoresinol and (+)-1-pinoresinol were unaffected by the irrigation regime. The tree water status had a marked effect on the concentration of volatile compounds, such as the C(6)-saturated and unsaturated aldehydes, alcohols, and esters.
authors.affiliation: Dipartimento di Scienze Economico-Estimative e degli Alimenti, Sezione di Tecnologie e Biotecnologie degli Alimenti, Università degli Studi di Perugia, Via S. Costanzo, 06126 Perugia, Italy. servimau@unipg.it
authors.forename: Maurizio
authors.initials: M
authors.lastname: Servili
authors.forename: Sonia
authors.initials: S
authors.lastname: Esposto
authors.forename: Enrico
authors.initials: E
authors.lastname: Lodolini
authors.forename: Roberto
authors.initials: R
authors.lastname: Selvaggini
authors.forename: Agnese
authors.initials: A
authors.lastname: Taticchi
authors.forename: Stefania
authors.initials: S
authors.lastname: Urbani
authors.forename: Gianfrancesco
authors.initials: G
authors.lastname: Montedoro
authors.forename: Matteo
authors.initials: M
authors.lastname: Serravalle
authors.forename: Riccardo
authors.initials: R
authors.lastname: Gucci
mesh_terms: D000383:Agriculture / Q000379:methods*; D005227:Fatty Acids / Q000032:analysis*; D006801:Humans; D031658:Olea / Q000254:growth & development*; D000069463:Olive Oil; D010636:Phenols / Q000032:analysis*; D010938:Plant Oils / Q000737:chemistry*; D012677:Sensation; D014835:Volatilization; D014867:Water
chemical_list: D005227:Fatty Acids; D000069463:Olive Oil; D010636:Phenols; D010938:Plant Oils; D014867:Water