尿素包合法富集苦瓜籽油中α-桐酸的工艺优化Enrichment of α-eleostearic acid from bitter gourd seed oil by urea adduction fractionation

以超临界CO2萃取的苦瓜籽油为原料，经皂化酸解法制得混合脂肪酸，再采用尿素包合法富集其中的α-桐酸。在单因素试验的基础上，采用正交试验对富集工艺条件进行优化。结果表明，α-桐酸的最佳富集工艺条件为：采用95%乙醇作为尿素溶剂，混合脂肪酸与尿素质量比1∶ 3，尿素与95%乙醇质量比1∶ 5，包合温度4 ℃，包合时间24 h。在最佳工艺条件下，α-桐酸纯度从苦瓜籽油中的28.83%提高至60.03%，产物中共轭亚麻酸相对含量达到71.28%。Using bitter gourd seed oil extracted by supercritical CO2 as raw material, the mixed fatty acid was obtained by saponification and acid hydrolysis, and then the α-eleostearic acid was enriched by urea adduction fractionation. Based on single factor experiment, the enrichment conditions were optimized by orthogonal experiment. The results showed that the optimal process for enriching α- eleostearic acid from bitter gourd seed oil were obtained as follows: with 95% ethanol as urea solvent, mass ratio of mixed fatty acid to urea 1∶ 3, mass ratio of urea to 95% ethanol 1∶ 5, adduction temperature 4 ℃ and adduction time 24 h. Under these conditions, the purity of α- eleostearic acid increased from 2883% (in bitter gourd seed oil ) to 60.03%, the total relative content of conjugated linolenic acid in the product reached 71.28%.