Chemometric characterization and sensory properties of virgin olive oils produced in Milas and Bodrum (Muğla) districts

Virgin olive oil is one of the most important sources of vegetable oil in daily consumption. in daily consumption in the Mediterranean diet, declaring as the one of cultural heritage of the world by UNESCO. Olive cultivation and olive oil production has been carried out since ancient times in Milas and Bodrum (Mugla) districts, which are important historical settlements of the Ancient Carian Civilization. Milas olive oil, under its own name, is an agro-industrial product having national (TPI Geographical Indication) and international (EU Geographical Indication – the first and only Turkish olive oil recognized by the EU for now) recognition product. Milas and Bodrum natural olive oils are also important in terms of history, culture, tourism and gastronomy. In this study, commercial and domestic virgin olive oil samples produced by the three-phase continuous system from Memecik variety olives, a single variety (monocultivar), grown in 12 different locations (n = 12) in Milas and Bodrum districts (Muğla) at the 2020-21 harvest year (during October-November) were analyzed. The large variation and significance differences were determined among chosen quality parameters FFA (0.5 – 4,22 oleic asit%); PV0,8 – 2,7 meq O2/kg yağ); K232 (0.85 – 2,31) and K270 (0,08 – 0,42) of the oil groups, according to the Milas and Bodrum locations.On the basis of national and international norms, the virgin oil samples of Milas and Bodrum locations are classified in different categories according to their FFA. Contents. FFA content of Memecik oil samples from Milas locations (2/6 extra virgin and 4/6 virgin olive oil) were found to be lower than those in Bodrum locations (1/6 virgin olive oil and 5/6 ordinary/lampante olive oil). The pigments of the oil samples (chlorophyll and carotenoid, respectively) ranged from 1.70 – 5.75 mg/kg and 1.13 – 3.80 mg/kg. Other chemical parameters, there was a wide variation and significant difference among the total phenolic contents (79,04 – 494,10 CAE mg/kg), DPPH (Antioxidant Activity 7,97 –41,72 %), alpha- tocopherol content (92,54 - 224,82 mg/kg) and oxidative stability [rancimat method – 110 °C, 20 lt/h air] (1,50 – 7,59 hours) according to Milas and Bodrum locations of the Memecik oil samples. The purity properties (fatty acids [FAs] profile, triacylglycerols [TAGs] distributions, and the sterol compositions and also an authenticity indicator of virgin olive oils) of all oil samples are generally in accordance with national and international official regulations. According to the results of the statistical tests, there were wide variations and significant differences among the major FAs and TAGs profiles and calculated their parameters of the oil samples based on Milas and Bodrum locations. The alterations of major FAs and their parameters were oleic (61,61 – 72,17%); Linoleic (10,10 – 19,73 %); linolenic (0,70 – 1,05%), palmitic (12,45 – 14,32%); Oleic / Linoleic (3,16 –7,15); Linoleic / Linolenic (13,42 – 19,27); IV (86,04 – 95,58); Oxidative Succ (597 ,88 – 1037,07) and TOSI (9,46 – 10,92 hours). The changes of major TAGs and some of their parameters were determined as OOO (24,15 – 36,81%); POO (17,99 – 23,36%); LOO (14,33 – 19,43%); OLL (2,39 – 7,52%) SOO (3,57 – 5,19%) and LLL (0,10 – 1,09%) also, LLL/ECN42 (0,23 – 0,56); ECN48/ECN46 (1,39 – 2,72); LOO/PLO (6,24 – 20,30). Virgin olive oil samples of Milas and Bodrum locations were classified by some biochemical profiles (fatty acids, TAGs and sterols) using the principal component analysis (PCA) by chemometrics from multivariate statistical methods. The glycerdic structures (TAGs and fatty acid profiles) and sterol compositions can be used for identification of monocultivar olive oils (Memecik cv growing Milas and Bodrum locations) with regard to authenticity and geographical classification.