Blending of soybean oil with selected vegetable oils: impact on oxidative stability and radical scavenging activity.

BACKGROUND Soybean oil may protect against cancer of the breast and prostate. It may also exert beneficial influence in combination with other oils. Here, blends (20%, v/v) of sea buckthorn oil (SEBO), camellia oil (CAO), rice bran oil (RBO), sesame oil (SEO) and peanut oil (PEO) with soybean oil (SBO) were formulated. MATERIALS AND METHODS Oxidative stability (OS) and radical scavenging activity (RSA) of SBO and blends stored under oxidative conditions (60°C) for 24 days were studied. By blending with different kinds oils, levels of polyunsaturated fatty acids (PUFA) decreased, while monounsaturated fatty acid (MUFA) content increased. Progression of oxidation was followed by measuring peroxide value (PV), p-anisidine (PAV), conjugated dienes (CD) and conjugated trienes (CT). RESULTS Inverse relationships were noted between PV and OS at termination of storage. Levels of CD and CT in SBO, and blends, increased with increase in time. The impact of SEO as additives on SBO oxidation was the strongest followed by RBO, CAO, SEBO and PNO. CONCLUSIONS Oxidative stability of oil blends was better than SBO, most likely as a consequence of changes in fatty acids and tocopherols' profile, and minor bioactive lipids found in selected oils. The results suggest that these oil blends could contribute as sources of important antioxidant related to the prevention of chronic diseases associated to oxidative stress, such as in cancer and coronary artery disease.