Suchergebnisse

The olive fly, Bactrocera oleae (Rossi), a serious threat to the olive crop worldwide, displays ovipositon preference for some olive cultivars but the causes are still unclear. In the present work, three Portuguese olive cultivars with different susceptibilities to olive fly (Cobrançosa, Madural, and Verdeal Transmontana) were studied, aiming to determine if the olive volatiles are implicated in this interaction. Olive volatiles were assessed by SPME-GC-MS in the three cultivars during maturation process to observe possible correlations with olive fly infestation levels. Overall, 34 volatiles were identified in the olives, from 7 chemical classes (alcohols, aldehydes, aromatic hydrocarbons, esters, ketones, sesquiterpenes, and terpenes). Generally, total volatile amounts decrease during maturation but toluene, the main compound, increased in all cultivars, particularly in those with higher susceptibility to olive fly. Sesquiterpenes also raised, mainly α-copaene. Toluene and α-copaene, recognized oviposition promoters to olive fly, were correlated with the infestation level of cvs. Madural and Verdeal Trasnmontana (intermediate and highly susceptible cultivars respectively), while no correlations were established with cv. Cobrançosa (less susceptible). No volatiles with inverse correlation were observed. Volatile composition of olives may be a decisive factor in the olive fly choice to oviposit and this could be the basis for the development of new control strategies for this pest. ; This work received financial support from the European Union (FEDER funds through COMPETE) and National Funds (FCT, Fundação para a Ciência e Tecnologia) through projects EXCL/AGR-PRO/0591/2012 "Olive crop protection in sustainable production under global climatic changes: linking ecological infrastructures to ecosystem functions" and Pest-C/EQB/LA0006/2013. Ricardo Malheiro thanks FCT, POPH-QREN (Programa Operacional Potencial Humano – Quadro de Referência Estratégico Nacional) and FSE (Fundo Social Europeu) for PhD grant (SFRH/BD/74675/2010). ; info:eu-repo/semantics/publishedVersion

[EN] The present study was conducted to determine the major bioactive lipid components of the seed oils of nine pomegranate (Punica granatum L.) cultivars grown in Spain, namely fatty acids, vitamin E and sterol compositions. The seeds yielded oil contents ranging from 4.44% to 13.70% of dry matter and showed high contents of polyunsaturated fatty acids (86.7.2–90.3%). The predominant fatty acid was 9,11, 13-octadeca-trienoic acid (punicic acid), a conjugated linolenic acid characteristic from pomegranate seeds, with contents between 3523 and 10,586 mg/100 g of seeds. Total tocopherol contents ranged from 135 to 525 mg/100 g of oil, with g-tocopherol as the main component, and with different compositional ratios between varieties. Concerning sterols in the oil, total amounts ranged from 364 to 553 mg/100 g, with a predominance of b-sitosterol. After performing principal component analysis, intercultivar differences were found, a potential tool for cultivar authenticity purposes. Moreover, the ingestion of pomegranate arils, with their seeds, increases their beneficial health properties. ; Authors are grateful to POCTEP - Programa de Cooperacao Transfronteiriga Espanha - Portugal for financial support (Project "RED/AGROTEC-Experimentation network and transfer for development of agricultural and agro industrial sectors between Spain and Portugal) as well as to the European Union (FEDER funds through COMPETE) and National Funds (FCT, Fundacao para a Ciencia e Tecnologia) through project Pest-C/EQB/LA0006/2013. ; Fernandes, L.; Pereira, JA.; López Cortés, I.; Salazar Hernández, DM.; Ramalhosa, E.; Casal, S. (2015). Fatty acid, vitamina E and sterols composition of seed oils from nine different pomegranate (Punica granatum L) cultivars grown in Spain. Journal of Food Composition and Analysis. 39:13-22. doi:10.1016/j.jfca.2014.11.006 ; S ; 13 ; 22 ; 39