Submitted to: European Journal of Lipid Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/28/2016
Publication Date: 5/8/2016
Publication URL: http://handle.nal.usda.gov/10113/5642496
Citation: Lew, H.N., Latona, R.J., Wagner, K., Nunez, A., Ashby, R.D., Dunn, R.O. 2016. Synthesis and low temperature characterization of iso-oleic ester derivatives. European Journal of Lipid Science and Technology. 118:1915-1925.
Interpretive Summary: Since saturated fats have high melting points, they are solids which can be harmful to our health and can cause damage to machinery. There is an urgent need to develop methods to produce fats with low melting points to replace the unwanted fats. In this paper, the researchers at ARS synthesized a series of modified branched-chain fatty acid ester derivatives that are liquid at room temperature with enhanced fluidity. These ester fats have been found to perform much better than the original fatty acids and saturated fats. These findings are important as these branched-chain ester fats can potentially replace solid materials which are often problematic at low temperatures.
Technical Abstract: Three new iso-oleic ester derivatives (i.e., isopropyl esters (IOA-iPrE), n-butyl esters (IOA-n-BuE), and 2-ethylhexyl esters (IOA-2-EHE)) were synthesized from iso-oleic acid (IOA) using a standard esterification method. These esterified alcohols were chosen because of their bulky and branched-chain alkyl groups which can reduce melting point in comparison to a smaller alkyl group such as methyl ester. The differential scanning calorimetry (DSC), cloud point and pour point results showed that the IOA-iPrE, IOA-n-BuE and IOA-2-EHE had much lower melting transition temperatures and cold flow properties than the methyl (IOA-FAME) and parent IOA. The oxidative and thermal stability by pressure (P-DSC) and thermogravimetric analysis (TGA) results also showed a very similar trend where the bulkier and branched-chain alkyl esters had better stability than the smaller headgroup esters.