Suchergebnisse

Virgin olive oil is unique among plant oils for its high levels of oleic acid, and the presence of a wide range of minor components, which are responsible for both its health-promoting properties and characteristic aroma, and only produced when olives are crushed during the industrial process used for oil production. The genetic variability of the major volatile compounds comprising the oil aroma was studied in a representative sample of olive cultivars from the World Olive Germplasm Collection (IFAPA, Cordoba, Spain), by means of the headspace solid-phase microextraction/gas chromatography–mass spectrometry–flame ionization detection (HS-SPME/GC-MS-FID). The analytical data demonstrated that a high variability is found for the content of volatile compounds in olive species, and that most of the volatile compounds found in the oils were synthesized by the enzymes included in the so-called lipoxygenase pathway. Multivariate analysis allowed the identification of cultivars that are particularly interesting, in terms of volatile composition and presumed organoleptic quality, which can be used both to identify old olive cultivars that give rise to oils with a high organoleptic quality, and in parent selection for olive breeding programs. ; Funding for this research came from the OLEAGEN project of Genoma España and the project AGL2011-24442 from the Programa Nacional de Recursos y Tecnologías Agroalimentarias, both financed by the Spanish Government

A wide genetic diversity has been reported for wild olives, which could be particularly interesting for the introgression of some agronomic traits and resistance to biotic and abiotic stresses in breeding programs. However, the introgression of some beneficial wild traits may be paralleled by negative effects on some other important agronomic and quality traits. From the quality point of view, virgin olive oil (VOO) from olive cultivars is highly appreciated for its fatty acid composition (high monounsaturated oleic acid content) and the presence of several minor components. However, the composition of VOO from wild origin and its comparison with VOO from olive cultivars has been scarcely studied. In this work, the variability for fruit characters (fruit weight and oil content, OC), fatty acid composition, and minor quality components (squalene, sterols and tocopherols content and composition) was studied in a set of plant materials involving three different origins: wild genotypes (n = 32), cultivars (n = 62) and genotypes belonging to cultivar × wild progenies (n = 62). As expected, values for fruit size and OC in wild olives were lower than those obtained in cultivated materials, with intermediate values for cultivar × wild progenies. Wild olives showed a remarkably higher C16:0 percentage and tocopherol content in comparison to the cultivars. Contrarily, lower C18:1 percentage, squalene and sterol content were found in the wild genotypes, while no clear differences were found among the different plant materials regarding composition of the tocopherol and phytosterol fractions. Some common highly significant correlations among components of the same chemical family were found in all groups of plant materials. However, some other correlations were specific for one of the groups. The results of the study suggested that the use of wild germplasm in olive breeding programs will not have a negative impact on fatty acid composition, tocopherol content, and tocopherol and phytosterol profiles provided that selection for these compounds is conducted from early generations. Important traits such as tocopherol content could be even improved by using wild parents. ; CICE project P11-AGR-7301, IFAPA projects AVA201601.2 and PR.PEI.IDF201601.2 partially funded by European Regional Development Fund, and European Union's Horizon 2020 RISE project BeFOre funded under the Marie Skłodowska-Curie grant agreement No. 645595. The conservation and management of olive cultivars at WOGB IFAPA Córdoba has been financially supported by INIA Projects (RFP 2012-00005; RFP 2013-00005). ; Peer reviewed

6 Páginas.-- 2 Figuras ; There is an increasing need for diversification of olive (Olea europaea L.) cultivars, mainly because of the new intensive industry and the current trend of establishing olive productions in new areas outside the Mediterranean basin. Olive breeding has traditionally been focused on the improvement of agronomic traits. However, the nutritional quality of virgin olive oil (VOO) is lately being considered as a breeding target because of the growing weight of scientific evidence supporting the positive impact of VOO on human health. Increasing VOO consumption, through improvement of its nutritional and sensory properties, will in turn have a positive effect on both consumer health and olive-producing areas. VOO metabolites responsible for its nutritional and sensory quality include components such as phenolics and volatile compounds, which are synthesized during the oil extraction process by endogenous enzymes. Here, we aimed to investigate olive diversity regarding the key VOO quality metabolites of olive accessions cultivated around the world. For this purpose, oils from 97 olive cultivars representative of the diversity found at the World Olive Germplasm Collection (CAP-UCO-IFAPA), located at IFAPA Centre "Alameda del Obispo" Cordoba, Spain, were obtained and the phenolic and volatile fractions were further analyzed. The component profiles were compared with those of a similar subset of seedlings arisen from the cross of two widely cultivated olive cultivars having contrasting oil compositions ('Arbequina' and 'Picual'). Results showed that a single cross provides enough variability to produce new olive cultivars with improved quality. The set of cultivars from the collection displayed, in general, higher levels of variability than the progeny cross for the main groups of volatile compounds. However, the latter displayed a wider variability than the set of cultivars under study for most of the main classes of phenolic compounds in the oil, except the lignans. ; Funding for this research came from the OLEAGEN project of Genoma España and AGL2011-24442 project from the Programa Nacional de Recursos y Tecnologías Agroalimentarias, both financed by the Spanish Government. ; Peer reviewed

35 Páginas; 2 Tablas; 5 Figuras ; Phenolics are claimed to be one of the main responsible for the health benefits associated to the long term consumption of virgin olive oil (VOO). The variability of the phenolic composition was studied in an olive cultivar core collection which holds an extensive genetic diversity. The most abundant VOO phenolics were the secoiridoid derivatives resulting from the hydrolysis of oleuropein, ligstroside and demethyloleuropein present in the fruit, which showed to be on average their main phenolic glucosides. Total phenolic compounds in the fruits and the oils were, in general, significantly and positively strong correlated (r = 0.82) with p < 0.001. Thus, the fruit phenolic content seems to be the main factor determining the synthesis of VOO phenolics during oil extraction. Data on phenolic composition would be of interest for the selection of optimal parents in olive breeding programs with the aim of obtaining new cultivars with improved functional quality. ; The funding for this research came from projects AGL2011-24442 and AGL2015-67652-R from the Programa Nacional de Recursos y Tecnologías Agroalimentarias financed by the Spanish Government. R G-R and C R-S are recipients of FPI fellowships. We are grateful to Mar Pascual for her excellent technical assistance. ; Peer reviewed

16 Páginas.-- 4 Figuras ; Ethanol is a substrate for the chemical synthesis of fatty acid ethyl esters (FAEE) during storage of virgin olive oil whose contents are officially regulated. Given the impact that the ethanol content might have on the olive oil commercialization, the level of this metabolite has been studied in an array of olive genotypes representing the diversity available in olive (Olea europaea L.). Substantial levels of ethanol have been found in the oils of all genotypes under study. Moreover, increasing levels of alcohol dehydrogenase activity have been found during olive fruit ripening in good correspondence with the accumulation of ethanol in advanced stages of fruit maturation. The results suggest that ethanol has a ubiquitous character in the fruits of Olea europaea and, therefore, in all the oils obtained from them. Besides, their concentration seems to depend on the cultivar, ripening stage and climatology, not discarding the influence of the growing conditions. Data suggest that the application of olive oil regulation for FAEE levels should consider the presence of basal levels of ethanol in the oils, which are quite high in many cultivars. ; Funding for this research came from the OLEAGEN project of Genoma España and the project AGL2011-24442 from the Programa Nacional de Recursos y Tecnologías Agroalimentarias, both financed by the Spanish Government. The plant materials evaluated here were obtained from the cooperative breeding program carried out at the University of Cordoba, and at the Institute of Agricultural and Fishery Research and Training (IFAPA), Spain. We are grateful to Mar Pascual for her excellent technical assistance. ; Peer reviewed

Virgin olive oil (VOO) is the only food product requiring official sensory analysis to be classified in commercial categories, in which the evaluation of the aroma plays a very important role. The selection of parents, with the aim of obtaining new cultivars with improved oil aroma, is of paramount importance in olive breeding programs. We have assessed the volatile fraction by headspace-solid-phase microextraction/gas chromatography-mass spectrometry-flame ionization detection (HS-SPME/GC-MS-FID) and the deduced aroma properties of VOO from a core set of olive cultivars (Core-36) which possesses most of the genetic diversity found in the World Olive Germplasm Collection (IFAPA Alameda del Obispo) located in Cordoba, Spain. The VOO volatile fractions of Core-36 cultivars display a high level of variability. It is mostly made of compounds produced from polyunsaturated fatty acids through the lipoxygenase pathway, which confirms to be a general characteristic of the olive species ( Olea europaea L.). The main group of volatile compounds in the oils was six straight-chain carbon compounds derived from linolenic acid, some of them being the main contributors to the aroma of the olive oils according to their odor activity values (OAV). The high level of variability found for the volatile fraction of the oils from Core-36 and, therefore, for the aroma odor notes, suggest that this core set may be a very useful tool for the choice of optimal parents in olive breeding programs in order to raise new cultivars with improved VOO aroma. ; This work was supported by the research projects AGL2011-24442 and AGL2015-67652-R from the Programa Nacional de Recursos y Tecnologias Agroalimentarias funded by the Government of Spain. We are grateful to Mar Pascual for her excellent technical assistance. ; We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI).