Unusually low pour point of fatty acid methyl esters with low saturated fatty acid content

Many oilseeds grown in Canada have unusual fatty acid profiles including Cruciferous oilseed varieties that have very low levels (<3%) of saturated fatty acid. In this study oil samples were obtained from five cultivars of Brassica rapa L ., seven cultivars of Brassica napus L. and five cultivars from other oilseeds species namely Brassica juncea L., Sinapis alba L., Camelina sativa L. and Linum usitatissimum L. The fatty acid profile, cloud point (CP) and pour point (PP) were determined for each oil sample. Fatty acid methyl esters (FAME) were synthesized from each oil sample. The saturated fatty acid content was highly correlated ( R 2 = 0.93) with PP in methyl esters prepared from Brassica sp. oils. In addition, we identified three publications where PP was measured on fatty acid methyl esters and found that the correlation of PP with saturated fat content was consistent with data presented herein. Since B. rapa oil exhibited superior low temperature properties, it was chosen for further studies of oxidative stability. B. rapa cultivars, with less than 3.5% saturated fat and less than 20% polyunsaturated fat, can be an excellent feedstock for production of oils with improved cold fluidity and oxidative stability. Practical applications: Here, we report studies on the relationship of saturated fat level with cold flow properties and polyunsaturated fat level with oxidative stability in fatty acid methyl esters made from oils with less than 10% total saturates. This research reveals potential keys to producing FAME with good oxidative stability and excellent low temperature performance. Brassica rapa with less than 3.5% saturated fat and less than 20% polyunsaturated fat has a pour point that is substantially better than oils with higher levels of saturated FAME. The lowest observed pour point was −21°C. FAME with this low temperature property could be used in a range of applications, such as cold‐flow improvers for biodiesel or bio‐lubricants. Effect of saturated fatty acid content on pour point (PP) of fatty acid methyl ester.