Determination of the Quality and Purity Characteristics of Olive Oils Obtained from Olives Cultivated in Different Regions of Turkey, Depending on Climatic Conditions

Abstract

Virgin olive oils (VOO) obtained from olives grown in different regions of our country, under changing climatic conditions, show different sensory and chemical properties. Due to the fact that primary production is affected by climatic and agricultural conditions and VOOs are supplied to the market by only physical processing. In order to determine whether these deviations are due to climatic conditions, VOOs were obtained from the olive samples collected from 39 orchards in four Region where VOO production is intense in Turkey. Analyzes were carried out regarding the quality and purity criteria of the VOOs. Samples were collected in 2017/18-2020/21 harvest years (-2 on-2 off). The maturity index (MI) values of olives and free fatty acidity (FFA), fatty acid ethyl esters (FAEE), delta-7-stigmastenol values of olive oils ranged between 0.94-4.15 and 0.07-1.27 (in oleic acid %), 1.56-27.32 mg/kg, 0.16-1.14%, respectively. Delta-7-stigmastenol values in 21 samples were outside the limit specified in the legislation (0.50-1.14%). The Fatty acid methyl esters (FAME) and FAEE of all olive oil samples were within the specified limits. In the study, multiple regression analysis was performed to investigate whether there is a relationship between climate data and delta-7-stigmastenol values by years. According to this result, it has been determined that the delta-7-stigmastenol value is high when the annual average relative humidity is low and the annual average temperature is high. There is an urgent need to make forward-looking plans due to climate change.