Methyl esters are prepared via two routes, i.e. transesterification of vegetable oils with methanol or esterification of fatty acids with methanol. The former is the more common method, but the reaction may be incomplete leaving some residual oil with the methyl esters. This oil, or oil residue, should be monitored and preferably removed to produce high quality methyl esters. Gas chromatography is commonly employed to detect oil residue in methyl esters but the technique requires a long time. In view of the importance of this analysis, MPOB has developed a more rapid alternative method.

Main Research: Dr. Mohtar Yusof