2024 Volume 73 Issue 1.2 Pages 45-52
Trans-fat or trans fatty acid (TFA), an invariable component of industrial fat, is considered as one of the major dietary factors associated with increased risk of coronary heart disease. TFA content in foods is not regulated in Japan. The aim of this study was to provide an understanding of the current status of TFA in edible vegetable oils commercially available in Japan. Using high resolution capillary gas chromatography on a very polar cyanosiloxane stationary phase (SP-2560, 100 m × 0.25 mm i.d.), we determined the fatty acid (FA) composition, total TFA levels, and TFA isomers of the 24 brands of edible vegetable oils obtained from the Japanese market. The total TFA contents of these samples were lower than 12.04 g 100 g−1 (av. 1.32 g 100 g−1), accounting for 1.43 % of total fatty acids. Excluding one brand with an exceptionally high TFA content found in a perilla oil sample, the TFA content averaged 0.92 %, which was similar to currently consumed margarines (0.88 %) and fat spreads (0.90 %) made chiefly from vegetable oils. The TFA profiles of the vegetable oils examined were similar to those in margarines and fat spreads, showing that the major TFA components were partially isomerized trans linoleic acid (9c,12c-18 : 2) and trans α-linolenic acid (9c,12c,15c-18 : 3). This suggests that most of the TFA in margarines and fat spreads are derived from the vegetable oils used as raw materials.
