Jennings B H, Akoh C C
Department of Food Science and Technology, Food Science Building, The University of Georgia, Athens, Georgia 30602-7610, USA.
J Agric Food Chem. 2000 Sep;48(9):4439-43. doi: 10.1021/jf000372r.
Capric acid (C10:0) was incorporated into rice bran oil with an immobilized lipase from Rhizomucor miehei as the biocatalyst. Effects of incubation time, substrate mole ratio, enzyme load, and water addition on mole percent incorporation of C10:0 were studied. Transesterification was performed in an organic solvent, hexane, and under solvent-free condition. Pancreatic lipase-catalyzed sn-2 positional analysis and tocopherol analysis were performed before and after enzymatic modification. Products were analyzed by gas-liquid chromatography (GLC) for fatty acid composition. After 24 h of incubation in hexane, there was an average of 26.5 +/- 1.8 mol % incorporation of C10:0 into rice bran oil. The solvent-free reaction produced an average of 24.5 +/- 3.7 mol % capric acid. In general, as the enzyme load, substrate mole ratio, and incubation time increased, the mole percent of capric acid incorporation also increased. Time course reaction indicated C10:0 incorporation increased up to 27.0 mol % at 72 h, for the reaction in hexane, and up to 29.6 mol % at 12 h, for the solvent-free reaction. The highest C10:0 incorporations (53.1 and 43.2 mol %) for the mole ratio experiment occurred at a mole ratio of 1:8 for solvent and solvent-free reactions, respectively. The highest C10:0 incorporation (27.9 mol %) for the reaction in hexane occurred at 10% enzyme load, and the highest incorporation (34.4 mol %) for the solvent-free reaction occurred at 20% enzyme load. Incorporation of C10:0 into rice bran oil declined with the addition of increasing amounts of water after reaching 30.3 mol % at 2% water addition in hexane, and in the solvent-free reaction after reaching 35.9 mol %.
以米黑根毛霉固定化脂肪酶作为生物催化剂，将癸酸（C10:0）掺入米糠油中。研究了孵育时间、底物摩尔比、酶负载量和加水量对C10:0摩尔掺入百分比的影响。酯交换反应在有机溶剂己烷中以及无溶剂条件下进行。在酶促改性前后进行了胰脂肪酶催化的sn-2位分析和生育酚分析。通过气液色谱法（GLC）分析产物的脂肪酸组成。在己烷中孵育24小时后，平均有26.5±1.8摩尔%的C10:0掺入米糠油中。无溶剂反应产生的癸酸平均为24.5±3.7摩尔%。一般来说，随着酶负载量、底物摩尔比和孵育时间的增加，癸酸掺入的摩尔百分比也增加。时间进程反应表明，对于己烷中的反应，在72小时时C10:0掺入量增加至27.0摩尔%，对于无溶剂反应，在12小时时增加至29.6摩尔%。摩尔比实验中，对于溶剂和无溶剂反应，C10:0的最高掺入量（分别为53.1和43.2摩尔%）分别出现在摩尔比为1:8时。己烷中反应的C10:0最高掺入量（27.9摩尔%）出现在10%的酶负载量下，无溶剂反应的最高掺入量（34.4摩尔%）出现在20%的酶负载量下。在己烷中加入2%的水后，C10:0掺入米糠油的量在达到30.3摩尔%后随着加水量的增加而下降，在无溶剂反应中达到35.9摩尔%后也出现这种情况。
