Olive trees (cv. `Leccino') were grown in Tuscany (Italy) to assess the effect of irrigation on oil yield and quality. Fruits were harvested at the stage of full pigmentation of the epicarp only (black skin) or at green-black skin color. Free acidity, peroxide number, K(232), K(270) and fatty acid composition were measured using official methods of analysis and volatile compounds by SPME-GS-MS; phenolic compounds were assayed colorimetrically. Irrigation did not affect free acidity, peroxide number and fatty acid composition of oils. The oleic acid ranged from 74.3 to 77.5% of total fatty acids in oils from dry-farmed and irrigated trees, respectively. Irrigation decreased total phenols and ortho-diphenols of oils from black ripe fruits (but not of those from green-black fruits) and increased several volatile compounds related to oil flavours. Irrigation decreased pungency and bitterness and increased flavours, such as fruity-apple or hay-like, of oils from black fruits.
Oil quality of olive cv. Leccino grown under irrigated or dry-farmed conditions
GUCCI, RICCARDO;
2004-01-01
Abstract
Olive trees (cv. `Leccino') were grown in Tuscany (Italy) to assess the effect of irrigation on oil yield and quality. Fruits were harvested at the stage of full pigmentation of the epicarp only (black skin) or at green-black skin color. Free acidity, peroxide number, K(232), K(270) and fatty acid composition were measured using official methods of analysis and volatile compounds by SPME-GS-MS; phenolic compounds were assayed colorimetrically. Irrigation did not affect free acidity, peroxide number and fatty acid composition of oils. The oleic acid ranged from 74.3 to 77.5% of total fatty acids in oils from dry-farmed and irrigated trees, respectively. Irrigation decreased total phenols and ortho-diphenols of oils from black ripe fruits (but not of those from green-black fruits) and increased several volatile compounds related to oil flavours. Irrigation decreased pungency and bitterness and increased flavours, such as fruity-apple or hay-like, of oils from black fruits.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
