EFFECTS OF PERIODS AND ALTITUDES ON THE PHENOLIC COMPOUNDS AND OIL CONTENTS OF OLIVES, cv. AYVALIK

Abstract

This study aimed to investigate the influence of periods and altitudes on the phenolic compounds of olive fruits and leaves; and oil contents of olives cv. Ayvalık located in Balıkesir province in Turkey. Surveys conducted in 4 different periods (July 2009, October 2009, January 2010 and April 2010) on 3 different altitudes (0 m, 300 m and 600 m from sea level). Fruit and leaf samples were collected with 3 replications for each periods & altitudes interaction. Phenolic compounds of both leaf and fruit samples were then investigated. Furthermore, acid compounds of fruits, fruit moisture contents (%), leaf moisture contents (%), pulp contents (%), fruit weight (kg/1000 fruits) and oil contents (%) were also tested for each samples. According to the results obtained, among the surveyed altitudes, highest fruit moisture content was measured at 300 m with 43.54%, whereas among the survey periods, the highest moisture content was found in October with 49.34%. Not surprisingly, among the tested period & altitude interactions, October 300 m was found to have highest fruit moisture content with 50.53% and followed by October 600 m with 49.37%. Highest leaf moisture content was measured from 0 and 300 m altitudes with 48.43% and 48.21%, respectively, where the April period was found to have highest leaf moisture content among the periods with 48.09%. Pulp content (%) results of present study are in accordance with the fruit moisture content (%) results. Fruit weight (kg/1000 fruits) was found to be highest in October and followed by July and January with 3.30 kg, 2.93 kg and 2.71 kg, respectively. Oil contents (%) have found to have clear differences among periods with lowest 1.52% in July and 28.89% in January. Altitude was also found to influence oil content where it was found that highest oil content was measured at highest altitude. Among the tested acid, Oleic acid was found to be highest and is followed by Palmitic acid, Linoleic acid, Stearic acid and Palmitoleic acid. Periods and altitudes are found to influence acid contents. Highest Oleic acid content was measured at 300 m altitude where the highest contents of other acids were measured at 600 m altitudes. Similarly, with the acid contents, phenolic compounds in leaf and fruit samples were found to be influenced by periods and altitudes. Highest Oleuropein content (µg g-1) in fruits measured in July at 0 m altitude with 825.50 where the lowest was measured at October 0 m 54.10. July period and 0 m altitude were found to have highest Oleuropein contents. On the other hand, no statistical difference was determined among the Oleuropein contents (µg g-1) in leaves among the tested altitudes. Furthermore, January period was found to have highest Oleuropein contents among the tested periods which has the lowest in fruits. Results may suggest that, as fruits ripen, Oleuropein accumulation in fruits decrease whereas it increases in leaves.