Trans fatty acids content in worldwide edible fats and oils: current trends and challenges

Trans fatty acids (TFA) have been related with multiple cardiovascular risk factors and higher risk of coronary heart disease. Partial hydrogenation, which converts liquid vegetable oils into solid or semi-solid fats with appropriate melting properties suitable for the production of shortenings and margarines, is one of the sources of TFA. In this study a worldwide comparison regarding the TFA content in edible oils and fats was performed. Oils and fats, from vegetable or animal origin, are essential ingredients for a variety of food products. The major dietary sources of TFA are foods containing partially hydrogenated vegetable oils, namely, shortenings and/or margarines, and animal fats as butter, while edible vegetable oils, in general have low contents. The content of TFA of vegetable oils can increase when subjected to drastic heating, for example deep-fat frying or oven baking. However, TFA formation strongly depends on several factors, namely, frying conditions (type of fryer, duration and temperature), frying material (oil/fat and the food itself), among others. In conclusion, a great variability between countries was observed for example for margarines, where Canada was one of the countries with the highest percentage of TFA (42.9% of total fatty acids) for margarines produced with partially hydrogenated vegetable oils. On the other hand, in Germany, Portugal, Austria and Canada as well, the identified margarines with lower content of TFA are mainly produced with nonhydrogenated fats. With respect to edible vegetable oils, in general, these have lower contents of TFA than margarines, shortenings and butters, as expected.This work was funded by National Institute of Health Dr. Ricardo Jorge, I.P., under the project ’PTranSALT’ (2012DAN828). Tania Goncalves Albuquerque acknowledges the PhD fellowship (SFRH/BD/99718/2014) funded by the FCT, FSE and MEC. This work has also been supported by the project ’Operacao NORTE-01-0145-FEDER-000011-denominada Qualidade e Segurança Alimentar-uma abordagem (nano)tecnológica’ and the project UID/QUI/50006/2013- POCI/01/0145/FEDER/007265 with financial support from FCT/MEC through national funds and co-financed by FEDER.