IMPROVING THERMAL STABILITY OF HIGH LINOLEIC CORN OIL BY BLENDING WITH BLACK CUMIN AND CORIANDER OILS

摘要

The aim of the present study was to enhance thermal stability and functionality of high linoleic corn oil by blending with healthy oils. Oil blends (10% and 20%, w/w) of black cumin oil and coriander oil with corn oil were formulated. Thermal oxidative stability and radical scavenging activity of corn oil and blends stored under oxidative conditions (60℃) for 15 days were studied. By increasing the proportion of black cumin oil and coriander oil in corn oil, levels of polyunsaturated fatty acids decreased, while monounsaturated fatty acids content increased. Progression of oxidation was followed by measuring peroxide value, conjugated dienes, and conjugated trienes. Inverse relationships were noted between peroxide value and oxidative stability at termination of storage. Levels of conjugated dienes and conjugated trienes in corn oil and blends increased with an increase in time. Corn oil:black cumin oil and corn oil:coriander oil blends gave 12-22% and 26-36% inhibition of 1,1-diphenyl-2-picrylhydrazyl radicals, respectively. Oxidative stability of oil blends were better than corn oil, most likely as a consequence of changes in fatty acids and tocopherols' profile, and minor bioactive lipids found in coriander and black cumin oils.