Seperation And Enrichment Technologies For Unsaturated Fatty Acid From Hippophae Rhamnoides L. Seed Oil

The seperation and enrichment technologies for the unsaturated fatty acids—oleic acid,linoleic acid andα-linolenic acid from Hippophae rhamnoides L.seed oil have been studied,maily including the saponification conditions of Hippophae rhamnoides L.seed oil and the optimizeation of the molecular distillation parameters.The factors which influence the saponification of Hippophae rhamnoides L seed oil including time,temperature and the alkali concentration were studied.The results showed that the optimal conditions for the saponification of Hippophae rhamnoides L seed oil were that the saponification time,temperature and the alkali concentration were 60min.,70℃and 1.0mol/L respectively.Under these conditions,a fatty acid yield of 91.08%was obtained,and the product contained 17.8%Oleic acid,27.2% linoleic acid and 24.9%linolenic acid.The seperation and enrichment of unsaturated fatty acid from Hippophae rhamnoides L.seed oil was carried out by molecular distillation.A central composite rotate design was used in order to optimize the operation parameters:distilling temperature and feed flow.Through response surface methodology,the optimal molecular distillation conditions were determined and the quadratic response surfaces were drawn from the mathematical models.The results suggested that distilling temperature and feed flow significantly affected both unsaturated Fatty Acid content and oil recovery in the two models.The optimum conditions for the recovering of unsaturated fatty acid were: distilling temperature 107.5℃and feed flow 1.0mL/min.Optimal values predicted by RSM for the total unsaturated fatty acid content and oil recovery were 82.4%and 62.6%,respectively.Experimental values were 82.7%and 65.7%,which are close to the predicted values.The content of oleic acid,linoleic acid and linolenic acid were 19.6%,32.6%,30.5%,which increased by 49.6%,31.9%and 43.9%respectively compared with the original oil. After that,ethyl esterification and following molecular distillation of Hippophae rhamnoides L seed oil have been studied.At the same condition(vacuum:0.1pa and the roller wiper speed:415rpm),the content of unsaturated fatty acids ethyl esters reached 88.2%with a recovery 82.1%when feed speed was 1.3～1.4mL/min and distilled temperation was 80～85℃.The results showed that ethyl esterification could decrease distilling temperature by 20～25℃,and increase feed speed by 30～40% with a much higher recorvery(82.1%) and largely increased content of unsaturated fatty acids(88.2%) to compare with that of direct distillation without ethyl esterification.(65.7%and 82.7%)...