本文采用了大孔树脂NKA-9作为载体负载脂肪酶RML，然后用于催化油酸含量为25%的大豆油脂以酶促脱酸并同时制备富含甘油二酯（DAG）的油脂产品。研究采用了扫描电镜（SEM）和X-射线光电能谱仪（XPS）对NKA-9负载酶前后进行了结构表征，结果表明RML已成功负载在NKA-9上。所得固定化酶RML@NKA-9催化油酸含量为25%的大豆油脱酸及DAG制备的优化条件为：反应温度50 ℃，甘油用量为油脂质量的8%，RML@NKA-9用量为油脂质量的3%，在该条件下反应8 h后达到平衡，此时DAG含量58.95%，游离脂肪酸（FFA）含量降低至1.50%。此外研究了RML@NKA-9的重复利用性，结果表明，RML@NKA-9重复使用4次后其酶活几乎没有损失，重复使用6次后其酶活为初始酶活的49.10%。本研究制备的RML@NKA-9能有效脱除高酸价油脂中的FFA，并获得了可观含量的DAG，具有一定的重复利用性，因此，RML@NKA-9具有较大的应用前景。

Macroporous resin NKA-9 was used as the support for the immobilization of lipase from the fungus Rhizomucor miehei (RML). The resin-supported RML (RML@NKA-9) was then used in the enzymatic deacidification of high-acid soybean oil with an oleic acid content of 25% for diacylglycerol (DAG) production. Structural characterization of the resin before and after RML loading using SEM and XPS revealed that RML had been successfully immobilized onto NKA-9. The optimized reaction conditions for enzymatic deacidification and DAG production were as follows: reaction temperature, 50°C; amount of glycerol, 8 wt% of the high-acid oil; and amount of RML@NKA-9, 3 wt% of the high-acid oil. Under these conditions, equilibrium was reached after 8 h of reaction, DAG content of 58.95% was achieved, and free fatty acid (FFA) content was reduced to 1.50%. Subsequently, the reusability of RML@NKA-9 was evaluated. Results indicated almost no activity loss after four cycles of use, and the retention of 49.10% of initial activity after six cycles of use. The RML@NKA-9 prepared in this study enabled the effective removal of FFAs from high-acid oil, achieved the production of considerable DAG content, and demonstrated a certain degree of reusability. Therefore, RML@NKA-9 possesses promising prospects for applications in oil processing.

国家自然科学基金项目（31772000）；广东药科大学2018-2019大学生“专创融合”项目