摘要
阿拉伯呋喃糖苷水解酶(Arabinoxylan arabinofuranohydrolase,AXAH)是阿拉伯木聚糖完全降解的关键酶之一。本文比较了过滤性能差异显著的江苏单二和港啤大麦麦芽与进口Metcalfe和Baudin大麦麦芽中的AXAH活力,发现单二和港啤中的AXAH平均活力只是Metcalfe和Baudin中平均活力的60%。为了进一步确定AXAH对大麦麦芽过滤性能的影响,文章通过硫酸铵分级沉淀、SP FF和Q FF离子柱层析以及Sephacryl S-100 HR凝胶过滤层析技术对单二大麦麦芽中AXAH进行了纯化,并将其添加到协定糖化过程的起始阶段。结果发现,当加酶量达到6mU/g时,协定糖化麦汁的过滤速度提高了34.2%,粘度降低了5.5%,麦汁浊度增加了32.5%。这一结果表明,添加AXAH及其与其他水解酶协同作用,促进了多聚阿拉伯木聚糖、β-葡聚糖以及高分子氮的降低,也促进了阿拉伯木聚糖和麦汁总氮含量的升高。
Arabinoxylan arab inofuranohydrolase（AXAH） is one of the key degrading enzymes of arabinoxylan. The activities of AXAH between Jiangsu barley malt（Dan＇er and Gangpi） and imported barley malt（Metcalfe and Baudin） with different filterability were compared,the results found that AXAH average activities in Dan＇er and Gangpi was only about 60% of that in Metcalfe and Baudin. In order to confirm effect of AXAH on the malt filterability, AXAH was isolated from Dan＇er barley malt by ammonium sulfate precipitation,SP FF and Q FF ion exchange chromatography and Sephacryl S-100 HR gel filtration chromatography,and was then added into mash during the initial period of congress mash. The filtration rate of wort increased 34.2% when 6mU/g of AXAH was added, the viscosity decreased 5.5% but the turbidity increased 32.5%. These results showed that the added AXAH and its synergistic effect with others hydroLases promote the decrease of contents of polymeric arabinoxylans （PAX）,β-glucan and macromolecular nitrogen, but the increase of contents of AX and total nitrogen of wort.
出处
《食品工业科技》
CAS
CSCD
北大核心
2014年第14期237-240,255,共5页
Science and Technology of Food Industry
基金
国家自然科学基金项目(31171736)
国家863计划(2013AA102109)
江苏省普通高等学校科研成果产业化推进项目(JHB2012-26)
江苏省科技支撑计划(BE2012397)
中央高校基本科研业务费专项资金资助(JUDCF10047)
江苏高校优势学科建设工程资助项目
