Abstract:

The technological conditions of purifying polyunsaturated fatty acids（PUFAs）derived from Jatropha curcas L. seed oil were studied by using urea adduction fractionation method. Different purification conditions on the purity of PUFAs were investigated，such as the kind of solvent，the mass ratio of unsaturated fatty acids（UFAs）-urea-methanol，crystallization temperature and cooling method. Methanol displayed the best results during the isolating process among three solvents. The purity of PUFAs increased gradually when the mass ratios of UFAs-urea were 1∶1，1∶1.5，1∶2 and 1∶2.5，with respective contents of PUFAs 69.38%，84.58%，94% and 100%，but the yield of PUFAs reduced from 54.51% to 9.63%. Increasing methanol dosage and keeping UFAs-urea mass ratio unchanged，the product yield of PUFAs increased evidently，but with slightly lower purity. Both purity （94.52%） and yield （23.78%）of PUFAs were optimized when inclusion temperature was －20 ℃. Slow cooling could lead to increased yield of raw PUFAs and purified product，with higher percentages of 10% and 4%，respectively，compared with rapid cooling.