Determination of trans-octadecenoic acids in German margarines, shortenings, cooking and dietary fats by Ag-TLC/GC.

According to numerous, even recent studies, trans fatty acids (TFA) are related to coronary heart disease. Thus, for the evaluation of the daily TFA-intake precise data on the content of TFA in currently available edible fats are of great interest. The present study gives a comprehensive overview on total trans-octadecenoic acid contents in 93 brands of German margarines, shortenings, cooking and dietary fats purchases in 1994, that were obtained by a two-dimensional chromatography method (Ag-TLC/GC). Conventional margarines were found to contain 0.17-25.90 wt% (n = 46) and shortenings/cooking fats 0.04-32.51 wt% (n = 16) TFA related to total fatty acids. Mean values were 9.32 resp. 9.79%, whereas dietary and reformatory fats exhibited a mean of 0.65% (n = 31) TFA. Among conventional margarines the highest TFA contents were detected in products (n = 11) derived exclusively from sunflower oil (mean value = 20.71%). Seasonal changes in single brands were relatively small.