Study of Physicochemical Properties of Extra Virgin Olive Oil Extracted from Koroneiki Variety in the Golestan Province durin Storage

Detection and determination of physicochemical properties, effective compounds of olive oil as well as its oxidative stability during storage is of particular importance, therefore, in this study, some properties of extra virgin olive oil obtained from the olive fruit of Kronaikei cultivar during two years of storage at 4°C and in darkness were investigated. The results showed that the acid value, peroxide value, anisidine index and wax content increased and the unsaponifiable matter, total sterol, and total phenol contents as well as antioxidant activity decreased. No significant change was observed in the amounts of equivalent carbon equivalent (ECN) of triacylglycerols during storage (p > 0.05). The main fatty acid and sterol were oleic acid and bet-sitosterol, respectively, and the major biophenolic compound was ferulic acid followed by cafeic acid, catechin, and oleuropein, respectively. Also, the monounsaturated fatty acid content decreased and the content of polyunsaturated fatty acids increased. No important change was seen in the quantity of fatty acid and sterol compounds of storaged olive oils. All quality parameters and physicochemical properties measured during the two years of storage of olive oils were in the range of the limits specified for extra virgin olive oil in the National Standard of Iran No. 1446 as titled “olive oil - characteristics and test methods”.