Studies was conducted to assess the thermal stability of oils with variation in the ratio of saturated to monounsaturated to polyunsaturated fatty acids S:M:P. Coconut, sesame and safflower oils were chosen for the study. Considering the nutritional significance of S:M:P ratio of 1:1:1, blends of coconut-sesame, coconut-safflower, sesame-safflower and coconut-sesame-safflower were prepared such that the S:M:P ratio was nearest to 1:1:1. This was achieved through a computer program set for the purpose. GLC analysis showed that the blend consisting of three oils had S:M:P ratio of 1.0:1.0:1.2 which was very close to the desired ratio of 1:1:1. The S:M:P ratios of the individual oils and the blends containing two oils varied widely from the desired S:M:P ratio. The individual oils and the blends were subjected to prolonged heating in an over maintained at 180 deg C for 12 hours. Analysis of the samples before and after heating showed that the blend containing three oils had comparatively superior thermal stability as compared to the blend containing two oils as well as the individual oils. Thus blended oils containing equal amounts of saturated, monounsaturated and polyunsaturated fatty acids have improved thermal stability which is the essential criteriou for frying oils.
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