Developmental expression of amylases during barley malting
Developmental expression of amylases during barley malting
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DOI：
10.1006/jcrs.2001.0367
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发表时间：
2001-05-01
影响因子：
3.8
通讯作者：
Cavalli-Molina, S
中科院分区：
文献类型：
--
作者：
Georg-Kraemer, JE;Mundstock, EC;Cavalli-Molina, S
本文研究了10个巴西大麦品种的淀粉酶活性和淀粉酶同工酶的质的变化随大麦苗龄的变化。所有品种在萌发初期均表现出少量同工酶。一般活动的增加，随后在接下来的几天里，新的同工酶被检测到，那些已经观察到，因为早期发芽增加了他们的活动。所有品种的淀粉酶活性增加，直到第三或第四天的发芽。一些品种保持这种高活性，直到分析的最后一天。其他品种在第5或第6天活性下降。没有检测到负责较高淀粉酶活性的电泳图谱或等位基因。β-淀粉酶活性总是上级于α-淀粉酶活性。高β-淀粉酶活性已经观察到的第二天的发芽，而α-淀粉酶活性开始增加，只有从第三天on. The获得的结果表明，至少对于分析的品种，有一个高的一般淀粉酶发芽的第四天左右，这表明发芽可以停止在这一刻，确保水解酶的活性在酿造过程中所需的得到满足。β-淀粉酶与糖化力呈轻度相关（r = 0.565），而α-淀粉酶与糖化力无相关性（r = -0.128），α-淀粉酶和β-淀粉酶与麦芽品质无相关性（r = 0.153和r =-0.348）。这些结果表明，大麦籽粒中的β-淀粉酶活性比α-淀粉酶活性更能很好地预测糖化力。(C)北京：科学出版社.
Amylase activity and qualitative changes in amylase isoenzymes as a function of barely seedling age were investigated in 10 Brazilian barley cultivars. All cultivars showed few isoenzymes in early germination. An increase in general activity ensued in the following days when new isoenzymes were detected and those already observed since early germination had their activity increased. All cultivars disclosed increase in amylase activity until the third or fourth day of germination. Some cultivars maintained this high activity until the last day analysed. other cultivars presented a decrease in activity in the fifth or sixth day. No electrophoretic pattern or allelomorph responsible for a higher amylase activity was detected. Beta-amylase activity was always superior to alpha-amylase activity. High beta-amylase activity was already observed on the second day of germination while alpha-amylase activity began to increase only from the third day on. The results obtained suggest that, at least for the cultivars analysed, there is a high general amylase around the fourth day of germination, indicating that germination could stop at this moment, ensuring that hydrolitic enzymes activity required in the brewing process is met. Beta-amylase was lightly correlated with diastatic power (r = 0.565) but no correlation was observed between alpha-amylase and diastatic power (r = -0.128), or neither between alpha- and beta-amylase with malting quality (r = 0.153 and r = -0.348, respectively). These results indicate that beta-amylase activity in barley grains, more than alpha-amylase, can be a good predictor of diastatic power. (C) 2001 Academic Press.