果胶酶生产及其在苹果汁澄清中的应用

对黑曲霉(Aspergillus niger)LLW-1菌株固态发酵生产酸性果胶酶的发酵培养基组成和发酵条件以及利用果胶酶澄清苹果汁的工艺条件进行了研究。固态发酵产酶条件为:250 mL三角瓶装10 g基料(豆饼∶麸皮=2.0 g∶8.0 g),(NH4)2SO420 g/kg,Tween-80 1.5 g/kg,玉米浆50 mL/kg,KH2PO43.0 g/kg,CaCl21.0 g/kg,MgSO4.7H2O 1.0 g/kg(均相对于基料),料水比1∶1.2,自然pH;31℃静置培养72 h,期间在为24 h翻曲1次,果胶酶活力达2 418 IU/g(干曲)。酸性果胶酶澄清苹果汁的工艺条件为:果汁自然pH值,果胶酶用量500IU/L(果汁),明胶添加量0.05 g/L(果汁),酶解温度和时间分别为45℃和1 h。

Production of Pectinanses and Its Application in Clarification of Apple Juice

Fermentation medium and conditions of solid-state fermentation for production of pectinases by Aspergillus niger LLW-1 strain and the process conditions of apple juice clarification treated with the pectinases were studied in this paper.The results of solid-state fermentation tests showed the optimum conditions∶ m(soybean flour) ∶ m(wheat bran) = 2∶8,corn steep of 50 mL/kg,(NH4)2SO4 20 g/kg,KH2PO4 3.0 g/kg,CaCl2 1.0 g/kg,MgSO4 1.0 g/kg,Tween-80 1.5 g/kg, water to base medium ratio of 1∶1.2,and natural pH.The pectinases activity reached 2 418 IU/g dry medium at 31℃ for 72 h.The process of apple juice clarification process treated with the pectinases were pectinases of 500 IU/L,gelatin of 0.05 g/L,apple juice of natural pH,and 45℃ for 1 hour.