Organoleptic and Chemical Properties of Coconut and Sesame Oils and their Blends

The chemical properties of six blends of coconut and sesame oils, and the organoleptic qualities of the blends and foods prepared with them were studied. The blends prepared for testing were: (1) 100% coconut oil; (2) 90 % coconut and 10 % sesame; (3) 75 % coconut and 25 % sesame; (4) 50 % coconut and 50 % sesame; (5) 25 % coconut and 75 % sesame; and (6) 100 % sesame oil. In sensory evaluations, on a Five-point Hedonic scale, all the oil blends were found to be acceptable for deep frying of fish and oil cakes, and shallow frying of noodles. Oil blends 1, 2 and 3, in descending order, received high sensory scores (4.2-3.8) for taste of deep fried fish; blends 6, 4 and 5 scored less (3.0 points each), but were acceptable. Blend 3 received the highest score of 4.3 for taste of both oil cakes and noodles; other blends ranged from 3.6-3.9. Colour and smell of oil blends 6, 5 and 4 scored only 2.2-2.5 and were not acceptable. Blends with 75% or more of coconut oil scoring 4.2-3.8 for colour and 3.7-3.3 for smell, were acceptable. All the oil blends stored well up to five months without exceeding the prescribed SLS standard for FFA values for edible coconut (white oil) and sesame oils. Blends 1, 2 and 3, containing less than 50 % sesame oil, can be stored for 6 months. After 6 months FFA levels showed an increasing trend. Iodine value did not change significantly but Peroxide values increased steadily during storage. Oil blends with higher proportions of coconut oil had relatively low peroxide values. Fatty acid composition of coconut oil can be altered by blending with sesame oil to increase the unsaturated fatty acid content of coconut oil without affecting its organoleptic qualities. Key words: sesame oil, saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, oil blends   doi: 10.4038/cocos.v18i0.990COCOS (2007), 18