Evaluation of Fatty Acid Compositions of the Margarines, Fat Spreads and Butters Currently Consumed in Japan

Using high-resolution capillary gas chromatography with flame ionization detection, we determined the fatty acid compositions of each ten sample of the margarines, fat spreads and butters currently consumed in Japan, with special reference to trans fatty acids. The total trans fatty acid contents of the margarines, fat spreads and butters examined were 0.19-1.49 g 100 g(-1) (av. 0.71 g 100 g(-1)), 0.16-0.88 g 100 g(-1) (av. 0.51 g 100 g(-1)), and 2.49-3.37 g 100 g(-1) (av. 2.74 g 100 g(-1)), respectively, clearly showing lower levels of trans fatty acids in all the samples of margarines and fat spreads than those of butters. In addition, the total saturated fatty acid contents of the margarines, fist spreads and butters were 17.3-45.6 g 100 g(-1) (av. 29.7 g 100 g(-1)), 4.51-25.6 g 100 g(-1) (av. 16.2 g 100 g(-1)), and 48.8-54.8 g 100 g(-1) (av. 52.4 g 100 g(-1)), respectively, also showing lower levels of saturated fatty acids in all the samples of margarines and fat spreads than those of butters. The most predominant trans fatty acid of butters is vaccenic acid (11t-18 : 1), comprising ay. 30.4 % of total trans fatty acids, while in margarines and fat spreads trans 18:2 (9c,12t- and 9t,12c-isomers) and trans 18:3 (9c,12c,15t- and 9t,12c,15c-isomers) were the major ones, suggesting that they were derived from refined vegetable oils as raw materials. The present study demonstrates that modern Japanese margarines and fat spreads have significantly lower levels of trans fatty acids and saturated fatty acids than butters.