Diversity for olive oil composition in a collection of varieties from the region of Valencia (Spain)

Olive (Olea europaea) has a long history of cultivation in the Mediterranean region of Valencia (Spain) and many local varieties exist in the area. According to their economic importance, varieties are classified as National, Principal, Secondary, Local, Disseminate, and Minor. We have evaluated during four seasons the olive paste moisture content, fat content, and olive yield, and the olive oil acidity, peroxide index, K232 and K270 parameters, total phenolics, K225 parameter, and fatty acids content in 45 varieties from the Collection of Olive Varieties from the Region of Valencia. Considerable diversity existed among varieties for all traits studied, and the variety effect was much greater than the season effect. Wide ranges of variation have been found for most traits, with differences among varieties being of more than 10-fold for total phenolics. The coefficient of genetic variation and heritability values have been generally high, in particular for fatty acids content. A few varieties were found to present values outside the ranges established in the regulations for several olive oil composition traits, although in some cases, like a variety with above the limit content of oleic acid, they are of interest for breeding. Several correlations were found to be significant between the K232 index and fatty acids profile, in particular with oleic acid. The values obtained for variety averages as well as the principal components analysis show that economically relevant varieties present a lower diversity for composition than varieties with low economic importance. In this respect, selection among traditional materials can be of interest to recover neglected varieties with specific composition profiles, as well as to identify sources of variation for breeding programmes. Discriminant analysis allowed a correct classification of 99.4% of samples, showing that composition profiles, in particular fatty acids content, is a powerful tool for chemometry and fingerprinting of olive oil. Overall, the results show that the wide diversity found in the collection studied, in particular in the less economically important varieties, is of interest for the selection and breeding of olive varieties with improved quality.Authors are grateful to Sergio Paz (Instituto Valenciano de Investigaciones Agrarias, Moncada, Spain) for his technical help, and also to the Laboratorio Agroalimentario de la Conselleria de Agricultura, Pesca, Alimentacion y Agua of the Generalitat Valenciana for the providing the facilities and funds for this research.Ruiz Dominguez, ML.; Raigón Jiménez, MD.; Prohens Tomás, J. (2013). Diversity for olive oil composition in a collection of varieties from the region of Valencia (Spain). Food Research International. 54(2):1941-1949. doi:10.1016/j.foodres.2013.06.023S1941194954

Caracterización por quimiometria de las variedades más importantes de aceitunas autóctonas y foráneas procedentes de la Colección Nacional de Cultivos de Aceituna de Turquía

In this study, twelve samples from domestic olive cultivars (Memecik, Uslu, Domat, Ayvalik, Çelebi, Memeli, Erkence, Gemlik, Çakir, Izmir Sofralik, Çekişte and Çilli) and nine samples from foreign olive cultivars (Picholine, Arbequnia, Hojiblanca, Manzanilla, Frontoio, Leccio, Saurani, Baroui and Meski) were investigated. All olive samples were collected from the National Olive Collection Orchard at Kemalpaşa – Izmir, Turkey. Basic qualitative parameters (free fatty acidity, peroxide value and spectrophotometric indexes), color scale and fatty acid profiles were determined in virgin olive oils obtained from domestic and foreign olive cultivars growing in the same pedoclimatic conditions. Large variations were observed among the cultivars, despitethe fact that the cultivars are planted in the same pedoclimatic conditions. Oils extracted from 21 samples obtained from domestic and foreign olive cultivars in the National Olive Genetic Bank of Turkey were classified with the multivariete stastistical method (Hierarchical Cluster Analysis, HCA) based on their fatty acid profiles. According to the HCA results (Euclidian method), the oils obtained from the domestic and foreign cultivars were separated into two and three groups, respectively.En este estudio, doce muestras de diferentes variedades de aceituna autóctonas (Memecik, Uslu, Domat, Ayvalik, Çelebi, Memeli, Erkence, Gemlik, Çakir, Izmir Sofralik, Çekişte y Çilli) y nueve muestras de diferentes variedades foráneas (Picholine, Arbequnia, Hojiblanca, Manzanilla, Frontoio, Leccio, Saurani, Baroui and Meski) fueron investigadas. Todas las muestras de aceitunas fueron obtenidas del National Olive Collection Orchard de Kemalpaşa – Izmir, Turquía. Los parámetros básicos cualitativos (acidez, valor de peróxidos e índices espectrofotométrico), escala de color y perfil de ácidos grasos fueron determinados en aceites de oliva virgen obtenidos de las aceitunas de las variedades autóctonas y foráneas, cultivadas en las mismas condiciones pedoclimáticas. Variaciones grandes fueron observadas entre todas las variedades, a pesar de que todas las variedades fueron cultivadas en las mismas condiciones pedoclimáticas. Los aceites extraidos de las 21 muestras obtenidas de variedades autóctonas y foráneas de aceitunas del National Olive Genetic Bank de Turquia fueron clasificados mediante métodos estadísiticos multivariante (ACH) basado en el perfil de ácidos grasos. De acuerdo a los resultados del HCA (método Euclidiano), los aceites obtenidos de las variedades autóctona y foráneas fueron separadas en tres y dos grupos, respectivamente