海藻酸钙/硅胶/羧甲基壳聚糖复合微球固定化柚苷酶的研究

Study on Immobilization of Naringinase on Calcium Alginate/Silica Gel/Carboxymethyl Chitosan Composite Microspheres

柚苷酶可对柑橘类水果中的柚皮苷等苦味物质进行水解,从而实现果汁的脱苦或普鲁宁等医药中间体的制备。作者采用滴入法制备具有环境友好且易获得特性的海藻酸钙/硅胶/羧甲基壳聚糖复合微球,以此作为载体,用于柚苷酶的固定化研究。结果表明,在硅胶/羧甲基壳聚糖质量比1.0∶1.5、交联时间2.0 h、固定化温度25℃、偶联时间4 h、给酶量465.6 U/mL的实验条件下,复合微球固定化柚苷酶的比活力、载酶率和酶活力回收率分别可达203.33 U/g、36.80%和62.15%。同时,相比游离柚苷酶,该复合微球固定化柚苷酶对pH和温度变化均显示出更好的稳定性,且更易操作和储藏。此外,海藻酸钙/硅胶/羧甲基壳聚糖复合微球固定化柚苷酶的应用能够进一步拓宽柚苷酶在食品、医药等领域的深入发展。

Naringinase can hydrolyze bitter substances, such as naringin in citrus fruits, which is applied in juice debittering or preparation of pharmaceutical intermediates, for example, prunin. In this study, calcium alginate/carboxymethyl chitosan/silica gel composite microspheres, which were environmental friendly and accessible with abundant resources, were prepared by dropping method and used as carriers for naringinase immobilization. The optimized specific enzyme activity, enzyme loading rate and enzyme activity recovery of immobilized naringinase could reach 203.33 U/g,36.80% and 62.15%, respectively, under the following conditions: silica gel/carboxymethyl chitosan mass ratio of 1.0∶1.5, crosslinking time of 2.0 h, immobilization temperature of 25 ℃, coupling time of 4 h, and enzyme dosage of 465.6 U/mL. Meanwhile, compared with the free naringinase, this immobilized naringinase exhibited better stability to pH and thermal changes, and showed the feasibility of operation and storage. Besides, the application of naringinase immobilized on calcium alginate/silica gel/carboxymethyl chitosan composite microspheres would further expand the development of naringinase in food, medicine and other fields.