Irrigation effects on quality, phenolic composition, and selected volatiles of virgin olive oils cv. Leccino.
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.
Servili
Maurizio
M
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
Esposto
Sonia
S
Lodolini
Enrico
E
Selvaggini
Roberto
R
Taticchi
Agnese
A
Urbani
Stefania
S
Montedoro
Gianfrancesco
G
Serravalle
Matteo
M
Gucci
Riccardo
R
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
D005227:Fatty Acids; D000069463:Olive Oil; D010636:Phenols; D010938:Plant Oils; D014867:Water