Trans-fatty acid is detrimental to human health (FAO, 2010). Therefore, many Western countries prohibit the use of trans-fatty acid in food.
Trans-fatty acid is derived from hydrogenation (in particular the partial hydrogenation process) to increase the density of oil in the production of edible oils such as soybean oil. Palm cooking oil, which naturally has a stable composition of saturated fatty acid and unsaturated fatty acid, is already semi-solid with a melting range of between 33oC and 39oC and therefore hydrogenation is unnecessary in the process so trans-fatty acid will not appear (Hariyadi, 2010).
In conclusion, palm cooking oil does not contain free trans-fatty acid. The properties of palm oil, especially stearin, can replace vegetable oils containing trans-fatty acid (Hariyadi, 2010; Giriwono and Andarwulan, 2016).