State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122 Jiangsu, People's Republic of China.
Appl Biochem Biotechnol. 2012 Sep;168(2):364-74. doi: 10.1007/s12010-012-9780-y. Epub 2012 Sep 5.
The ability of immobilized lipase from Rhizomucor miehei (Lipozyme RM IM) to catalyze the reaction of high-acid rice bran oil (RBO) and monoglyceride (MG) for diacylglycerol-enriched rice bran oil (RBO-DG) preparation was investigated. The effects of substrate ratio, reaction temperature, time, and enzyme load on the respective content of free fatty acid (FFA) and DG in the final RBO-DG products was investigated. Enzyme screening on the reaction was also investigated. Response surface methodology (RSM) was used to optimize the effects of the reaction temperature (50-70 °C), the enzyme load (2-6 %; relative to the weight of total substrates), and the reaction time (4-8 h) on the respective content of FFA and DG. Validation of the RSM model was verified by the good agreement between the experimental and the predicted values. The optimum preparation conditions were as follows: MG/RBO, 0.25; temperature, 56 °C; enzyme load, 4.77 %; and reaction time, 5.75 h. Under the suggested conditions, the respective content of FFA and DG was 0.28 and 27.98 %, respectively. Repeated reaction tests indicated that Lipozyme RM IM could be used nine times under the optimum conditions with 90 % of its original catalytic activity still retained.
研究了固定化米根霉脂肪酶（Lipozyme RM IM）催化高酸值米糠油（RBO）与单甘酯（MG）反应制备富含二酰基甘油的米糠油（RBO-DG）的能力。考察了底物比、反应温度、时间和酶用量对最终 RBO-DG 产品中游离脂肪酸（FFA）和 DG 各自含量的影响。还对反应中的酶筛选进行了考察。采用响应面法（RSM）优化了反应温度（50-70°C）、酶用量（2-6%；相对于总底物的重量）和反应时间（4-8 h）对 FFA 和 DG 各自含量的影响。通过实验值与预测值之间的良好一致性验证了 RSM 模型的验证。最佳制备条件如下：MG/RBO，0.25；温度，56°C；酶用量，4.77%；反应时间，5.75 h。在建议的条件下，FFA 和 DG 的各自含量分别为 0.28%和 27.98%。重复反应试验表明，在最佳条件下，Lipozyme RM IM 可重复使用 9 次，其原始催化活性仍保留 90%。
