FATTY-ACIDS IN CANADIAN MARGARINES

The fatty acid composition of fifty brands of margarine sold in Canada was determined by a combined procedure of capillary gas liquid chromatography on a polar cyanopropylpolysiloxane liquid phase column and infrared spectrophotometry. The total saturated fatty acids ranged from 13.0 to 31.5% with palmitic acid ranging from 5.9 to 24.3% and stearic acid from 3.4 to 10.7%. A wide range in the linoleic acid levels (3.1 to 54.5%) occurred in the tub margarines; most contained 30 to 40% range followed by another group which contained 10 to 20%. Among the print margarines, 9 of the 19 samples contained less than 5% linoleic, while only 4 samples contained more than 10%. Linolenic acid ranged from 0 to 6.4% with the margarines based on canola and soybean oils having the highest concentrations. The total trans fatty acids in print and tub margarine samples ranged from 26 to 50% and 0 to 36% respectively. Mono-trans-octadecadienoic acid was the major trans polyunsaturated fatty acid group and ranged from 0 to 7.6%. The trans, trans-octadecadienoic acid was generally less than 1% but three samples contained more than 1%. A high concentration of these trans polyunsaturated fatty acids was found in canola and soybean oil based margarines.