MCM-41固定化柚苷酶脱苦葡萄柚汁

Naringinase immobilized on MCM-41 to debitter grapefruit juice

以介孔分子筛MCM-41为载体,戊二醛为交联剂,采用吸附-交联法进行了柚苷酶的固定化。研究了酶液浓度、戊二醛浓度、吸附交联时间和固定化pH对固定化效果的影响,对影响固定化效果的因素进行了分析。确定最佳的固定化条件为:酶液浓度为0.4mg/mL,戊二醛浓度2.0%,吸附交联时间为6h,固定化pH为4.0(醋酸缓冲液)。采用海藻酸钠和聚乙烯醇对制备的固定化酶进行二次包埋处理,并应用于葡萄柚汁的脱苦。结果显示,游离酶和MCM-41固定化酶对果汁的脱苦率分别为96.65%和92.90%,海藻酸钠和聚乙烯醇二次固定化的柚苷酶脱苦率分别为72.64%和70.90%。脱苦后的果汁营养成分与理化指标均有一定程度降低。为柚苷酶的固定化提供了一种新型的载体材料,为固定化柚苷酶在果汁脱苦中的工业化应用提供了理论基础。

The mesoporous molecular sieve MCM-41 was employed as a support to immobilize naringinase.And adsorption method and crosslinked with the bifunctional agent glutaraldehyde（GA） were adopted to improve enzyme loading.The effects of naringinase and GA concentration,immobilization time and pH on the activity of immobilized naringianse were investigated.The main factors which influenced the immobilization process and properties of the immobilized enzyme also were analyzed and discussed.The optimum conditions for immobilization of naringinase were as follows：naringianse and GA concentration were 0.4mg/mL and 2.0% respectively,and the immobilization time of 6h in pH 4.0（acetate buffer）.Sodium alginate（SA） and polyvinyl alcohol（PVA） were used to embed the immobilized MCM41-naringinase secondly and apply to debitter grapefruit juice.The results showed that debittering rate of the free and immobilized MCM41-narnginase were 96.65% and 92.90%,and embedded naringinase secondly with SA and PVA were 72.64% and 70.90%,respectively.The nutrition and physical characteristics of the grapefruit juice after debittered were decreased to some extent.A new matrix material to immobilize naringinase and provided the theoretical basis for its industrial applications in debitter juice.