Marchal L M, Jonkers J, Franke G T, de Gooijer C D, Tramper J
Food and Bioprocess Engineering, Department of Food Technology and Nutritional Sciences, Wageningen Agricultural University, Bomenweg 2, 6703 HD Wageningen, The Netherlands.
Biotechnol Bioeng. 1999 Feb 5;62(3):348-57. doi: 10.1002/(sici)1097-0290(19990205)62:3<348::aid-bit11>3.0.co;2-f.
The hydrolysis of amylopectin potato starch with Bacillus licheniformis alpha-amylase (Maxamyl) was studied under industrially relevant conditions (i.e. high dry-weight concentrations). The following ranges of process conditions were chosen and investigated by means of an experimental design: pH [5.6-7.6]; calcium addition [0-120 microg/g]; temperature [63-97 degrees C]; dry-weight concentration [3-37% [w/w]]; enzyme dosage [27.6-372.4 microL/kg] and stirring [0-200 rpm]. The rate of hydrolysis was followed as a function of the theoretical dextrose equivalent. The highest rate (at a dextrose equivalent of 10) was observed at high temperature (90 degrees C) and low pH (6). At a higher pH (7.2), the maximum temperature of hydrolysis shifted to a lower value. Also, high levels of calcium resulted in a decrease of the maximum temperature of hydrolysis. The pH, temperature, and the amount of enzyme added showed interactive effects on the observed rate of hydrolysis. No product or substrate inhibition was observed. Stirring did not effect the rate of hydrolysis. The oligosaccharide composition after hydrolysis (at a certain dextrose equivalent) did depend on the reaction temperature. The level of maltopentaose [15-24% [w/w]], a major product of starch hydrolysis by B. licheniformis alpha-amylase, was influenced mostly by temperature.
在工业相关条件（即高干重浓度）下，研究了地衣芽孢杆菌α-淀粉酶（Maxamyl）对支链淀粉型马铃薯淀粉的水解作用。通过实验设计选择并研究了以下工艺条件范围：pH值[5.6 - 7.6]；钙添加量[0 - 120微克/克]；温度[63 - 97摄氏度]；干重浓度[3 - 37%（w/w）]；酶用量[27.6 - 372.4微升/千克]和搅拌速度[0 - 200转/分钟]。水解速率随理论葡萄糖当量的变化而跟踪测定。在高温（90摄氏度）和低pH值（6）条件下观察到最高水解速率（葡萄糖当量为10时）。在较高pH值（7.2）时，水解的最高温度移至较低值。此外，高钙水平导致水解的最高温度降低。pH值、温度和添加的酶量对观察到的水解速率表现出交互作用。未观察到产物或底物抑制现象。搅拌对水解速率没有影响。水解后（在一定葡萄糖当量下）的低聚糖组成确实取决于反应温度。麦芽五糖（淀粉被地衣芽孢杆菌α-淀粉酶水解的主要产物之一）的含量[15 - 24%（w/w）]主要受温度影响。
