Study of phenolic compounds in virgin olive oils of the Picual variety

Abstract

Monovarietal Picual olive oils possibly represent 25% of the world's olive oil production. HPLC was used to analyse phenolic compounds and tocopherols in Picual olive oils obtained during two successive crop seasons (1999/2000 and 2000/2001) and from different geographic areas of the Jaén province, which is located in the south of Spain. Oils obtained at the beginning of each season had a higher content of each phenolic compound than those obtained at the end, although this effect was more pronounced for orthodiphenols than for nonorthodiphenols. The main phenolic compound detected in this monovarietal oil was the aglycon of oleuropein followed by the other secoiridoid aglycons. Lignan concentration in oil showed low variability with season and harvesting time, and pinoresinol in particular was present at a concentration of about 40 ppm. Therefore, the total polyphenol content of this monovarietal oil ranged from 300 to 700 ppm. Similarly, significant differences in these compounds were not detected between geographic areas. This monovarietal oil is very stable due to its high content of oleic acid and for this reason, the storage of oils for 2 years in amber glass bottles caused only a 30% decrease in phenolic compounds. An increase was found in simple phenols such as hydroxytyrosol and tyrosol liberated from the acid hydrolysis of the secoiridoid aglycons, and minor losses in tocopherols were also observed. These data provide a basis for the evaluation of polyphenol intake from virgin olive oil consumption, particularly from the monovarietal olive oil most consumed in the world.

Rapid Quantification of the Phenolic Fraction of Spanish Virgin Olive Oils by Capillary Electrophoresis with UV Detection

“…It is possible to say that, in general, the results obtained by this method are in good agreement with those previously reported obtained by using other techniques (5, [28][29][30][31], although the comparison can often be hard because the results are not expressed in identical units (in terms of the same reference standard).…”

Chemical Characterization and Kinetic parameter determination under Rancimat test conditions of four monovarietal virgin olive oils grown in Morocco

“…Therefore the content of phenolic compounds is an important parameter which determines the characteristics and quality of olive oil (Garcia et al, 2002;Kowalski et al, 2004). The total amounts of phenolic compounds in olive oil depend on various factors such as cultivar, climate and irrigation, altitude and technological conditions during extraction (Garc et al 2003;Garcia et al, 2002).…”

Single-cultivar extra virgin olive oil classification using a potentiometric electronic tongue

“…Previously, the use of hydro-methanolic mixtures was already reported to overcome this issue (Rodríguez-Méndez, Apetrei, & de Saja, 2008). These alcoholic extracts are expected to be rich in polar compounds, such as sterols, polyphenols and tocopherols, which differ considerably among olive oils cultivars and are the main contributors to olive oil bitterness, astringency and pungency (Apetrei et al, 2010;Carrasco-Pancorbo et al, 2006;García, Brenes, Garcí, Romero, & Garrido, 2003;García, Brenes, Romero, García, & Garrido, 2002;Matos et al, 2007;Morelló, Romero, & Motilva, 2004;Romero, & Brenes, 2012). Therefore their use as suitable discriminating descriptors was investigated, since it is expected that those compounds (e.g., sterols, polyphenols and tocopherols) are the major constituents of the hydro-ethanolic extracts.…”