Improving the oxidative stability of sunflower oil by blending with Sclerocarya birrea and Aspongopus viduatus oils

Abstract

Improvement of the oxidative stability of sunflower kernel oil (SKO) by blending with highly stable unconventional edible Sudanese oils was investigated. Blends (9 :1, 8 :2, 7 : 3, 6 : 4, ww) of sunflower oil with Sclerocarya (Sclerocarya birrea) oil (SCO) and melon bug (Aspongopus viduatus) oil (MBO), respectively, were studied with respect to the fatty acid composition, the oxidative stability (Rancimat 120C) and stability at 70C using peroxide value. By increasing the proportion of SCO and MBO in SKO, the linoleic acid content decreased from 46.3 to 31.2% (SCO) and 30.1% (MBO), respectively, while the oleic acid content increased from 41.3 to 51.0% (SCO) and 43.9% (MBO), respectively. As a result of blending SKO with SCO and MBO, respectively, the oxidative stability in the Rancimat test was improved from 47 to 147% in (SCO) and from 5 to 68% (MBO) compared to the SKO as control, with increasing parts of SCO and MBO, respectively. Storage of the blends at 70C showed that the increase of the peroxide value as a measure of oxidation was remarkably lower for the mixtures of MBO and SCO with SKO than for pure SKO. This study demonstrated a means for improving the stability of sunflower oil by blending with SCO and MBO. © Copyright 2005, Blackwell Publishing.