IMPROVING THE STABILITY AND RADICAL-SCAVENGING ACTIVITY OF SUNFLOWER OIL UPON BLENDING WITH BLACK CUMIN (NIGELLA SATIVA) AND CORIANDER (CORIANDRUM SATIVUM) SEED OILS

Blends (10 and 20%, w/w) of black cumin oil (BCO) and coriander oil (CO) with sunflower oil (SFO) were formulated. Oxidative stability (OS) and radical-scavenging activity of SFO and blends stored under oxidative conditions (60C) for 15 days were studied. By increasing the proportion of BCO and CO in SFO, linoleic acid content decreased, while oleic acid content increased. Progression of oxidation was followed by measuring peroxide value (PV), conjugated dienes (CDs) and conjugated trienes (CTs). Inverse relationships were noted between PV and OS at termination of storage. Levels of CDs and CTs in SFO and blends increased with an increase in time. SFO:BCO and SFO:CO blends gave 8-18 and 22-32% inhibition of DPPH center dot radicals, respectively. OS of oil blends was better than SFO, most likely as a consequence of changes in fatty acids' and tocopherols' profile, and minor bioactive lipids found in CO and BCO. PRACTICAL APPLICATIONS Blending of vegetable oil has emerged as an economical way of modifying the physicochemical characteristics of vegetable oils besides enhancement in oxidative stability. Among new sources of vegetable oils, black cumin seed oil (BCO) and coriander seed oil (CO) are of interest and may play a major role in human nutrition and health. At different concentrations of BCO and CO, oxidative stability of high-linoleic sunflower oil (SFO) was enhanced. Furthermore, blends enriched with BCO and CO had a strong antiradical action. The optimal levels of BCO and CO enrichment will depend on the actual application. It is anticipated that commercial exploitation of SFO:CO and SFO:BCO blends will soon be realized.