The effect of olive growing region and storage temperature on physicochemical properties of extracted oil

The aim of this study was to evaluate the effect of different storage conditions of olive (yellow variety) harvested from two different regions of the Ardabil province (Parsabad and Aslandouz) on the some physicochemical characteristics. Climatic conditions are reasons for different methods of storage in each area. For this purpose, harvested olives from two different regions were packed in polyethylene bags and stored at temperatures of 20°C, 5°Cand-18°Cfor 60 days, respectively and during this time, sampling was done at different times and the process of changes in the quality of oils (such as acidity, humidity, peroxide index and sum of saturated and unsaturated fatty acids) produce dfrom olives were investigated after 60 days. The results showed that the harvest region and differen tstorage condi tions of olive had a significant effect (P<0.05) on various properties. The results of mean comparison in different samples of olive oil showed that increasing of temperature and storage time were lead to increase of extracted oil content, acidity and pero xide value of olive oil, but the moisture content of olive oil was reduced. Also, Acidity of all samples was about 0.62% in terms of oleic acidin the first day of storage, so that the most of increase in the acidity of olives (up to 3.5% in terms of oleic acid) were belonged to olives stored at 20°C in the 40 thday of storage. Moreover, the results of the GC showed that the highest total unsaturated fatty acids (including palmitoleic, oleic, linoleic and linolenic acids) and the lowest total saturated fatty acids (including palmitic, stearic and arachidic acids) were 80.35% and 19.57% from Parsabad region olives (stored at-18°C), respectively. Inoverall, the treatment related to olive oil from Parsabad region (stored at-18°C), had lower moisture content, acidity and peroxide value than the other olives.