胡椒经地衣芽孢杆菌发酵脱皮过程中的主要酶系及pH值变化  

Dynamic Changes in Main Enzyme Activities and pH during Pepper(Piper nigrum L.) Decortication by Bacillus licheniformis Fermentation

作　　者：熊海波[1,2] 侯源源[1] 刘四新[1] 苗子健[1] 李从发[1] 

机构地区：[1]海南大学食品学院,海南海口570228 [2]海南大学环境与植物保护学院,海南海口570228

出　　处：《食品科学》2011年第15期205-208,共4页Food Science

基　　金："十一五"国家科技支撑计划项目(2007BAD76B02)

摘　　要：采用地衣芽孢杆菌进行静置液态发酵对胡椒进行脱皮,与生产实践中传统水沤法脱皮对比,研究二者发酵脱皮过程中的果胶酶、木聚糖酶、纤维素酶和发酵液pH值的动态变化。结果表明:在发酵脱皮过程中,两种方法的聚半乳糖醛酸酶(PG)和果胶裂解酶(PL)变化规律相似,都出现两次酶活力高峰;而纤维素酶活力都很低,果胶酯酶(PE)酶活力都比较高;在传统水沤法中木聚糖酶活力出现两个高峰,而在发酵法中木聚糖酶活力在脱皮后期逐渐上升;pH值变化总趋势也相似,脱皮完成时pH值均在5～5.5之间。由此推知,胡椒鲜果发酵脱皮过程中果胶酶系起主要作用,脱皮前期PG、PL先作用于果胶类物质,破坏胶质复合体的稳定结构,PE再作用于果胶分子,形成果胶酸,同时pH值降低,脱皮后期木聚糖酶活力上升,半纤维素降解加快,在多种酶的协同作用下,胡椒鲜果最终完成彻底脱皮。Static liquid-state Bacillus licheniformis fermentation was used for pepper decortication and compared with traditional water retting.Meanwhile,the dynamic changes of pectinases,xylanase,cellulase and pH during pepper decortication by the two methods were explored.The results showed that the changes of polygalacturonase（PG） and pectin lyase（PL） revealed a similar pattern with two activity peaks during both decortication processes.However,cellulase activity was low and the pectin esterase（PE） activity remained high.Similar pH changes were observed during both decortication processes pH was between 5 and 5.5 at the end of decortication.Xylanase activity showed two peaks in traditional water retting method and a gradual increase in the late stage of Bacillus licheniformis fermentation.Therefore,pectinase might play an important role during pepper decortication.In the early stage of decortication,PG and PL first acted on pectin substances and damaged the pectin complex structure,and then PE hydrolyzed pectin molecules to form pectic acid accompanied with pH decrease.Further,xylanase activity increased gradually in the late stage of decortication and as a result,hemicellulose was rapidly depolymerized.Therefore,pepper decortication was completed under the synergistic action of multiple enzymes.

关 键 词：胡椒 脱皮 发酵法 水沤法 地衣芽孢杆菌 果胶酶 木聚糖酶 纤维素酶 

分 类 号：Q814.9[生物学—生物工程]