Senanayake S P J Namal, Shahidi Fereidoon
Department of Biochemistry, Memorial University of Newfoundland, St. John's, Newfoundland, A1B 3X9 Canada.
J Agric Food Chem. 2002 Jan 30;50(3):477-83. doi: 10.1021/jf010757p.
Enzymatic acidolysis of borage oil (BO) or evening primrose oil (EPO) with eicosapentaenoic acid (20:5n-3; EPA) was studied. Of the six lipases that were tested in the initial screening, nonspecific lipase PS-30 from Pseudomonas sp. resulted in the highest incorporation of EPA into both oils. This enzyme was further studied for the influence of enzyme load, temperature, time, type of organic solvent, and mole ratio of substrates. The products from the acidolysis reaction were analyzed by gas chromatography (GC). The highest incorporation of EPA in both oils occurred at 45-55 degrees C and at 150-250 enzyme activity units. One unit of lipase activity was defined as nanomoles of fatty acids (oleic acid equivalents) produced per minute per gram of enzyme. Time course studies indicated that EPA incorporation was increased up to 26.8 and 25.2% (after 24 h) in BO and EPO, respectively. Among the solvents examined, n-hexane served best for the acidolysis of EPA with both oils. The effect of the mole ratio of oil to EPA was studied from 1:1 to 1:3. As the mole ratio of EPA increased, the incorporation increased from 25.2-26.8 to 37.4-39.9% (after 24 h). The highest EPA incorporations of 39.9 and 37.4% in BO and EPO, respectively, occurred at the stoichiometric mole ratio of 1:3 for oil to EPA.
研究了用二十碳五烯酸（20:5n-3；EPA）对琉璃苣油（BO）或月见草油（EPO）进行酶促酸解。在初步筛选中测试的六种脂肪酶中，来自假单胞菌属的非特异性脂肪酶PS-30使EPA在两种油中的掺入量最高。进一步研究了该酶在酶负载量、温度、时间、有机溶剂类型和底物摩尔比方面的影响。酸解反应产物通过气相色谱（GC）进行分析。EPA在两种油中的最高掺入量出现在45 - 55摄氏度和150 - 250个酶活性单位时。一个脂肪酶活性单位定义为每克酶每分钟产生的脂肪酸（油酸当量）的纳摩尔数。时间进程研究表明，EPA在琉璃苣油和月见草油中的掺入量分别在24小时后增加到26.8%和25.2%。在所研究的溶剂中，正己烷最适合EPA与两种油的酸解反应。研究了油与EPA的摩尔比从1:1到1:3的影响。随着EPA摩尔比的增加，掺入量从25.2 - 26.8%增加到37.4 - 39.9%（24小时后）。油与EPA的化学计量摩尔比为1:3时，EPA在琉璃苣油和月见草油中的最高掺入量分别为39.9%和37.4%。
