An experiment was carried out in a high-density olive (Olea europaea L. 'Frantoio') orchard in Tuscany over two growing seasons to compare the effect of three different irrigation regimes on virgin olive oil (VOO) quality. Subsurface drip irrigation was used to supply 100% (FI), 46-48% (DI) or 2-6% (CI) of water needs for about 14 weeks during the summer. The irrigation regime had no effect on fatty acids composition of VOO and the unsaturated/saturated and mono-unsaturated/polyunsaturated ratios. On the contrary, FI trees yielded oils with lower concentrations of total phenols and ortho-diphenols than those obtained from severely stressed trees (55 and 40% of CI oils, respectively). Over the two-year period regulated deficit irrigation allowed to recover 85 and 84% of total phenols and ortho-diphenols, respectively, of the maximum concentrations yielded by CI trees. Tree water status had a marked effect on the concentrations of volatile compounds. In particular, oils from CI trees had lower concentration of alcohols and esters than FI oils (28 and 38%, respectively), whereas no significant differences were observed between FI and DI oils. These results show that deficit irrigation can be used to optimize the concentration of phenolic and volatile compounds in VOO.
Effect of different irrigation regimes on quality of virgin olive oil
CARUSO, GIOVANNI;GUCCI, RICCARDO;
2014-01-01
Abstract
An experiment was carried out in a high-density olive (Olea europaea L. 'Frantoio') orchard in Tuscany over two growing seasons to compare the effect of three different irrigation regimes on virgin olive oil (VOO) quality. Subsurface drip irrigation was used to supply 100% (FI), 46-48% (DI) or 2-6% (CI) of water needs for about 14 weeks during the summer. The irrigation regime had no effect on fatty acids composition of VOO and the unsaturated/saturated and mono-unsaturated/polyunsaturated ratios. On the contrary, FI trees yielded oils with lower concentrations of total phenols and ortho-diphenols than those obtained from severely stressed trees (55 and 40% of CI oils, respectively). Over the two-year period regulated deficit irrigation allowed to recover 85 and 84% of total phenols and ortho-diphenols, respectively, of the maximum concentrations yielded by CI trees. Tree water status had a marked effect on the concentrations of volatile compounds. In particular, oils from CI trees had lower concentration of alcohols and esters than FI oils (28 and 38%, respectively), whereas no significant differences were observed between FI and DI oils. These results show that deficit irrigation can be used to optimize the concentration of phenolic and volatile compounds in VOO.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
