尿素包合法纯化小桐子油多不饱和脂肪酸的工艺

Purification of polyunsaturated fatty acid from Jatropha Curcas L.seed oil by urea adduction fractionation

研究了尿素包合法纯化小桐子油脂中多不饱和脂肪酸(PUFAs)的工艺条件。考察了溶剂种类、不饱和脂肪酸/尿素/甲醇质量比、包合温度和降温方式对PUFAs纯化效果的影响。3种溶剂中,甲醇对PUFAs的纯化效果最好。当UFAs/尿素质量比为1∶1、1∶1.5、1∶2、1∶2.5时,PUFAs纯度不断提高,分别为69.38%、84.58%、94%和100%,PUFAs收率从54.51%逐步降至9.63%;UFAs/尿素质量比一定,甲醇用量增加,PUFAs收率明显提高,但对其纯度略有下降。包合温度为-20℃时,PUFAs的纯度(94.52%)和收率(23.78%)两个因素可同时得到兼顾。缓慢降温有利于PUFAs的收率和产品得率的提高,快速降温得到的PUFAs的收率比缓慢降温低10%左右,产品得率比缓慢降温的低4%左右。

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.