Trans fatty acids in Canadian margarines:: Recent trends

The fatty acid composition and the trans fatty acid content of the top-selling 109 Canadian margarines were determined by a combined capillary gas-liquid chromatography/infrared spectroscopy method. The 109 brands accounted for 68% of the margarine brands sold in Canada and represented 74% of the market share. The mean level of total trans content in tub margarines (n = 79) was 18.8% (g/100 g fatty acids) and ranged from 0.9 to 46.4%. The most frequent occurrence of trans in tub margarines was in the 15-20% range; 48 of the 79 tub brands were in this range but seven brands contained more than 40% trans. The trans content of hard margarines (n = 30) ranged from 16.3 to 43.7% and the mean value was 34.3%. In 20 of the 109 brands, the levels of trans, trans isomers of linoleic acid exceeded the maximum level of 1% recommended for Canadian margarines. The levels of cis,trans/trans,cis isomers of linoleic acid were also high; 78 brands contained more than 1% and in 16 brands, the levels were in the 6-7% range. Linoleic acid content in the 109 brands ranged from 1.0 to 45.2% and averaged 18.3%. In 33 samples, linoleic acid was below the level of 5% recommended by an ad hoc committee of Health Canada. Moreover, in these; the total trans-content exceeded 30%, and trans polyunsaturated fatty acid level was greater than 5%. There were eight margarines prepared from nonhydrogenated fat and their total trans content was below 2.5%. From the trans content and market share of each of the margarine brands, the average intake of trans fatty acids from margarine was estimated as 0.96 g/person/d. The intake of trans fatty acids in Canada from various sources was previously estimated by us as 8.4 g/person/d. Thus it is suggested that only 11% of the dietary trans fatty acids are supplied by margarines and the majority of trans fatty acids in the Canadian diet is derived from hidden fats in fast foods and bakery products.