β-葡萄糖苷酶的固定化及其用于制备大豆异黄酮的研究

采用25%脱乙酰壳聚糖滴入15%的NaOH与30%的CH3OH组合的成球凝结溶液制备中空球形脱乙酰壳聚糖。适量的β-葡糖糖苷酶用4%戊二醛与中空球形脱乙酰壳聚糖偶联，实现β-葡糖糖苷酶的固定化。中空球形壳聚糖固定化的β-葡萄糖苷酶适宜pH值为4.0、适宜温度为68℃、相对酶活力为87.9%。在50℃用60%乙醇提取大豆异黄酮糖苷，得率约为4.0mg/g。再用固定化β-葡糖糖苷酶水解异黄酮糖苷，70℃、1h后，再经超滤、固定化酵母细胞等处理，可制备纯度达94%的大豆异黄酮甙元。

Study on Immobilization of β-Glucosidase and Production of Soybean Isoflavones with Immobilizedβ-Glucosidase

The hollow globular chitosan was made by injecting mixture of 15% NaOH and 30% CH3OH into 25% chitosan solution. Thenβ-glucosidase was immobilized by the coupling effect of 4% gluluraldehyde and the hollow globular chitosan. It was found that the optimum reaction temperature and pH and relative activity of immobilized β-glucosidase are 68 ℃, 4.0 and 87.9%, respectively. The soybean isoflavone glucoside was firstly extracted with a yield of 4.0 mg/g from soybean meal by 60% alcohol at 50 ℃, and then hydrolyzed by immobilizedβ-glucosidase at 70 ℃ for 1 h. After treatments of ultrafiltration and immobilized yeast fermentation, finally soybean isoflavone with the purity of 94% was obtained.