Fatty Acid Composition of Edible Oils in the Malaysian Market, with Special Reference to Trans-fatty Acids

A total of 113 samples of various types of palm and palm kernel oil products, their fractions, palm-based and non-palm-based cooking oils obtained from local manufacturers and the retail market were analysed for their trans-fatty acid compositions and contents by capillary gas chromatography. Trans-fatty acids were generally absent in crude palm and palm kernel oils. However, they were present at 0.01%-0.06% in refined palm kernel products and 0%-0.61% in refined palm products, all well below the 1.0% level stipulated by some importers. These trans-fatty acids were formed from their natural cis-isomers as a result of the high temperature used during deodorization. In cooking oil, the trans-fatty acid contents of palm-based products were 0.25%-0.67%, again well below 1%. However, in the non-palm-based cooking oils, the contents of the 14 samples ranged from 0.43%-3.83%. The higher contents in the non-palm-based oils were expected as they had high contents of unsaturated fatty acids, which are more prone to isomerization at elevated temperatures. Journal of Oil Palm Research Vol. 14 No. 1, June 2002, p. 1-8