Fatty acid composition and contents of trans monounsaturated fatty acids in frying fats, and in margarines and shortenings marketed in Denmark

This study examined trans monounsaturated fatty acid contents in all margarines and shortenings marketed in Denmark, and in frying fats used by the fast-food restaurants Burger King and McDonald's. Trans C-18:1 content was 4.1 +/- 3.8% (g per 100 g fatty acids) in hard margarines, significantly higher than the content in soft margarines of 0.4 +/- 0.8%. Shortenings had an even higher content of trans C-18:1, 6.7 +/- 2.3%, than the hard margarines. Margarines and shortenings with high contents of long-chain fatty acids had about 20% total trans monoenoic of which close to 50% were made up of trans long-chain fatty acids. Both fast-food frying fats contained large amounts of trans C-18:1, 21.9 +/- 2.9% in Burger King and 16.6 +/- 0.4% in McDonald's. In Denmark the per capita supply of trans C-18:1 from margarines and shortenings and frying fats has decreased steadily during recent years. The supply of trans C-18:1 from margarines and shortenings in the Danish diet is now 1.1 g per day.