Characterization by chemometry of the most important domestic and foreign olive cultivars from the National Olive Collection Orchard of Turkey

Abstract

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.<br><br>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

Geographical Classification of Turkish Virgin Olive Oils from the Aegean Region for Two Harvest Years Based on Their Fatty Acid Profiles

“…The linoleic acid (18:2n6) levels for the two harvest years ranged from 8.08 to 17.17% and 5.36 to 18.76%, respectively ( Table 1). The oleic acid/ linoleic acid ratios (minimum value of 7) [9], as an indicator for cultivar characterization and oxidative stability, for the two harvest years ranged from 3.85 to 9.52 and 3.27 to 14.77, respectively. The nutritional (18:2/18:3, l/ln) fatty acid ratios (a value considered to be optimal) of the oil samples of domestic cultivars ranged from 10.17 to 39.93 and 8.93 to 26.76 for the two harvest years, respectively.…”

“…Among the components of olive oil, fatty acid profiles are extremely useful for characterization and discrimination of an olive cultivar or its geographical location [2,5]. There are several studies on geographical characterization of virgin olive oils from Turkish [6][7][8][9][10] and North countries of Mediterranean basin [11][12][13][14][15][16][17][18][19][20][21][22][23][24] based on fatty acid profiles.…”

“…Multivariate statistical (PCA, DA or CA) evaluation of data is not a solution, but is a very promising approach for the evaluation of analytical data as to the geographical origin of a virgin olive oil sample. However, some studies have attempted to verify and classify the origins of certain virgin olive oils from major olive oil-producing countries (Italy, Spain, France, Greece, and nowadays Turkey), using their fatty acid profiles aided by multivariate statistical methods, such as principal component analysis (PCA), hierarchical cluster analysis (HCA) and discriminant analysis (DA) [5,6,[9][10][11][12][13][14][15][16][17][18][19][20][21][22]24]. Although Turkey is the world's fifth largest producer of olive oil (5%) and contributes 11.3% of the world's exports [3], there is a lack of data elucidating the characterization and classification of olive oil produced and marketed in Turkey.…”

Fatty Acid Profiles of Virgin Olive Oils from the Five Olive‐Growing Zones of Extremadura (Spain)

“…MUFAs in olive oil are particularly relevant because of their nutritional value and their effect in increasing the oil's oxidative stability [14]. The main FA of this group was oleic acid, with contents ranging from 68.82 % for La Siberia to 79.30 % for Sierra Norte de Cáceres.…”

“…The other principal FAs are linoleic (18:2), palmitic (16:1) and stearic (18:0) acids. While variations in the FA profiles depend mainly on the variety, there is also a dependence on the production zone, climate, latitude, degree of ripeness of the olives at the time of harvest, extraction system and storage conditions [13][14][15][16].…”