Chemometric characterization of raw olives from important Turkish table olive cultivars Cvs. using HPLC–DAD method based on their biophenolic profiles

In this study, raw fruits of important olive cultivars mostly used in the Turkish table (and oil) olive sector, Ayvalik, Gemlik, Domat, Memecik and Uslu, were investigated based on their biophenolic profiles by a HPLC–DAD method. Biophenolic compounds have great importance in olive processing (table and oil) technology and human nutrition physiology and are commonly found in natural products obtained from fruits and vegetables, including table olives and olive oil. Raw olive fruits samples, grown in Bornova and Kemapaşa which are the experimantal areas of Olive Research Institute (İzmir-Turkey), were harvested in different maturity stages during two corp years (2007–2008). The total phenolic content (TPC) and the simple biophenolic profile analysis of raw olive samples were carried out using UV/VIS spectroscopic and HPLC–DAD methods, respectively. It was showed that domestic olive cultivars, mostly used in table and oil technologies, exposed great differences in biophenolic profiles due to the cultivar and harvest time according to the results of this study. TPC data for all raw samples varied from1 89.8 mg GAE /100 g (Domat) to 421 mg GAE /100 g (Uslu). Hydroxytyrosol (HT) was the major phenolic compound for all raw olive samples and it varied from 58.70 mg/100 g (Uslu) to 27.53 mg/100 g (Memecik). The highest amount of tyrosol (TY) compound was found Uslu (21.23 mg/100 g) while Ayvalik had the lowest amount of this compound (6.13 mg/100 g). In this study, the raw fruits of the domestic five table cultivars were characterized and classified chemometric methods (Principal Component Analysis, PCA and Hierarchical Cluster Analysis, HCA) based on their simple phenolic compounds. Luteloin (LT) was effective on the characterization of Uslu cultivar while Gemlik was classified with the apigenin (APG). The Hydroxytyrosol (HT) was discriminative in classification of Memecik cultivar whereas the tyrosol (TY) played role in characterization of Ayvalik cultivar.