COMPARATIVE STUDY OF PENOLIC COMPOUNDS OF LEAVES AND FRUITS OF OLEA EUROPAEA L.

European olive (Olea europaea L.) is one of the oldest cultivated plants on Earth. In addition to the nutritional value of the fruit, medications made from different parts of the olive are of great importance cause they exhibit a wide range of pharmacological action. The main objective of the present study was a comparative analysis of the content of phenolic compounds in the leaves and fruits of varieties and subspecies of European olives growing in the climatic conditions of the Southern Coast of Crimea. Total phenolics and flavonoids were determined spectrophotometrically. HPLC with diode-array detection was applied to determine individual components. As a result of the comparative study of the phenolic compounds of leaves and fruits in four varieties and one subspecies of olives it was found that total phenolics in the leaves of olives are in the range of 740–980 mg/100 g (on a wet weight basis) and total phenolics in fruits are in the range of 840–1260 mg/100 g (on a wet weight basis). Flavonoids content in the leaves is in the range of 190–312 mg/100 g and in the range of 59–990 mg/100 g in the fruits. Luteolin-7-O-glucoside, apigenin-7-O-glucoside, rutin and oleuropein were identified among the phenolics of leaves and fruits. It was found that the oleuropein was a majour component either in leaves or in fruits of four varieties of olives but rutin was a majour component in the fruits of the O. europaea subsp. cuspidata subspecies. The content of flavonoids and oleuropein in the leaves and fruits of the most frost-resistant variety Nikitskaya turned out to be the lowest among all the studied samples. It may be related to the participation of these substances during preparation of the variety to the effects of below-freezing temperatures. It has been shown that the content of phenolic compounds in leaves and fruits of O. europaea depends on the variety and agroclimatic growing conditions.