BLENDING OF SUNFLOWER OIL WITH GRAPE SEED OIL: IMPACT ON PHYSICO-CHEMICAL PARAMETERS AND RADICAL SCAVENGING ACTIVITY

Abstract

Sunflower oil (SFO) was blended with grape seed oil (GSO) in order to improve its quality. If sunflower oil is a traditional one on Romania market the grape seed oil is a non-conventional one which has a high content in unsaturated fatty acids like oleic and linoleic ones and a large amount of tannins like the oligomeric proanthocyanosides. Also, grape seed oil is rich in bioactive compounds like phenolic components, tocopherols, e.g. thus making it a valuable source in order to improve the nutritional quality of the blended oils. The main goal of the present work was to compare and correlate the physical-chemical and radical scavenging activity of the SFO blended with GSO in different proportions: 10:0, 9:1, 8:2, 7:3 and 0:10, w/w. The physical-chemical properties analyzed in this study were refractive index, iodine value, peroxide value, saponification value and acid value. The radical scavenging activity was measured by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method. The results showed that by increasing the proportion of GSO in SFO,  the physico-chemical  parameters values decreased, while the radical scavenging activity increased. Oxidative stability of oil blends was improved with the level increase of GSO. This study showed that the quality of sunflower oil may be improved with the addition of grape seed oil.