Evaluation of the Effect of Refining Operations on Olive Oil Sterols in Iranian Oil Industry

Olive oil due to the unique characteristics being monounsaturated, resistant to oxidation, having considerable quantities of phenolic compounds namely α-tocopherol, being liquid at room temperature with excellent taste and aroma might be regarded as a healthy oil. The aim of this study is to investigate the effect of refining operation on the sterol content of olive oil in Iran's oil industry.

Samples were prepared before and after refining from three brands of olive oil production industries. Each sample was subjected to determination of iodine, saponification values and isolation of non saponifiable mater. The samples were also subjected to fatty acid and sterol analyses and compositions according to the standard methods defined nationally.

The results of this study indicated that small changes in fatty acid composition and values related to fatty acids have occurred. The study also indicated that the sterols have been affected by refining operations and has been lost and collected mainly in the distillate.

The results of this study confirms that olive oil refining affects the quantities of sterols and these compounds with others namely tocopherols are collected in the distillate. Therefore distillate collected after deodorization of olive oil might be considered as a valuable fraction to be used in industries.