Enhanced Stability of Refined Soybean Oil Enriched with Phenolic Compounds of Olive Leaves

Abstract

Soybean oil is a common vegetable oil, which is used for edible purposes. However, this oil is rich in unsaturated fatty acids that enhance oil deterioration by their oxidation. Such deterioration can be reduced using suitable antioxidants, preferably natural antioxidants. This work was made to assess the suitability of phenolic compounds that can be extracted from olive leaves to improve soybean oil stability against oxidation. Olive leaves extracts were tested for their content of phenolic compounds and have been then added to soybean oil which was subjected to accelerated oxidation. The oxidation stability was monitored following several technical methods commonly used for this purposes such as peroxide value, p-Anisidine value, as well as induction time by Rancimat method. The results have proved that the extracts of olive leaves can be used efficiently as a safe natural antioxidant in edible oils. However, the dose to be added should be adjusted as to achieve the activity of synthetic antioxidants.