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This report's general objective is to propose a method for extracting the polyphenols in lyophilised olive pulp. We studied the qualitative profiles of the corresponding phenolic extracts, using samples of Picual, Hojiblanca and Arbequina olive varieties, in order to compare the proposed method with traditional fresh pulp methods. The proposed method, based on the extraction of lyophilised olive pulp with a mixture of ethanolewater (80:20 v/v), resulted in less hydrolysis of oleuropein and ligstroside, and the extract was obtained in a 33% shorter time using 30% less solvent. © 2010 Elsevier Ltd., This study was made possible by AGL2007-66139-C02-01 from the Interministerial Science and Technology Commission (CICYT, Spain).

A study has been conducted to determine the influence of integrated olive production on the quality of extra virgin olive oil. On two different dates, samples from three different holdings were taken in integrated production (I) parcels, and in conventional production (C) parcels, both adjacent. The analytical determinations were free acidity, peroxide value, K232 and K270, fatty acid composition, esterols, phenolic compounds, tocopherols, stability to oxidation and sensory analysis. Most interesting among the results obtained were total contents of esterols and tocopherols, higher in olive oils of integrated production. Se ha realizado un estudio para ver la influencia de la producción integrada del olivar sobre la calidad del aceite de oliva virgen. Se tomaron muestras de aceitunas de tres fincas distintas, en parcelas correspondientes a olivar de secano, de producción integrada (I), y en parcelas adyacentes a estas de producción convencional (C), en dos fechas diferentes. Las determinaciones analíticas realizadas han sido acidez libre, índice de peróxidos, K232 y K270, composición de ácidos grasos, esteroles, compuestos fenólicos, tocoferoles, estabilidad oxidativa y análisis sensorial. En los resultados obtenidos destaca que los valores más altos de esteroles totales y tocoferoles corresponden a los aceites de producción integrada. Así mismo, los aceites de producción convencional presentan mayor contenido de fenoles totales y parecen ofrecer mayor estabilidad.

Phenolic compounds in Spanish virgin olive oil were analyzed by GC-MS after an SPE diol cartridge extraction and clean-up procedure. Posterior derivatization to trimethylsilyl (TMS) ethers using a mixture of hexamethyldisilazane:dimethylclorosilane (HMDS:DMCS) in pyridine (3:1:9) was performed. Several compounds were detected and 21 of them were identified. Free phenols such as hydroxytyrosol, tyrosol, tyrosyl and hydroxytyrosyl acetate, and aldehydic and dialdehydic forms of elenolic acid linked to tyrosol and hidroxytyrosol were the most abundant compounds. Likewise, oxidation products coming from the aldehydic and dialdehydic forms of elenolic acid, and of ligstroside and oleuropein aglycons, were detected, and their structure confirmed by other mass spectrometry technique, i.e., HPLC-APCI-MS. Individual oxidation products were isolated from an oxidized sample by preparative HPLC, converted to TMS ethers and re-analyzed by GC-MS. When necessary and for identification purposes, selective ion monitoring, namely, GC-MS-SIM, was employed. This is the first time that structures of oxidized forms are determined by GC-MS. © 2005 Elsevier B.V. All rights reserved., This study was supported by a CICYT research project (AGL 2001-2004 –CO2).

The present study developed two objetives: 1) to study the possibility of repeatedly using disposable C18 columns 2) to determine an appropriate analytical scheme and the inherent systematic error in the method to evaluate bitter substances in virgin olive oil. The results confirmed that we were able to recover the principles of olive oil without reducing the effectiveness of the C18 a columns with repeated uses at least ten times. The evaluation method errors of the bitter taste have been determined, in order to determine it precision. The confidence limits calculated for defined work schemes have given sufficient precision. El presente trabajo ha perseguido dos objetivos fundamentales: 1) estudiar la posibilidad de utilizar repetidamente las columnas "disposable" (de un sólo uso) C18 y 2) determinar el error y esquema analítico apropiado del método de evaluación del amargor del aceite de oliva virgen. Los resultados obtenidos nos permiten afirmar que las recuperaciones de los productos responsables del amargor del aceite no disminuyen al reutilizarse las columnas al menos durante las diez utilizaciones probadas. Se han determinado los errores del método de evaluación del amargor para determinar su precisión. Los límites de confianza calculados para definir los esquemas de trabajo han dado suficiente precisión.