Zhu Jing, Gao Yi, Li Xingfei, Lu Cheng, Zhou Xing, Chen Long, Qiu Chao, Jin Zhengyu, Long Jie
The State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi 214122, China.
The State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China.
Food Chem. 2025 Nov 30;493(Pt 1):145748. doi: 10.1016/j.foodchem.2025.145748. Epub 2025 Jul 28.
Maltogenic α-amylase (MA, EC 3.2.1.133), which shows high thermal stability, can cleave long starch chains linked by α-1,4 glycosidic bonds. And glycogen branching enzyme (GBE, EC 2.4.1.18) can increase the branching degree of starch. At high temperatures, Elevated temperatures enhanced starch solubilization, improving the accessibility of both MA and GBE to glucan chains. Therefore, ungelatinized normal corn starch (NCS) emulsion (20 % w/w, dry basis) was first pretreated with α-amylase (MA) at 70 °C for 2 h, followed by enzymatic modification using the thermostable Pyrococcus horikoshii OT3 GBE mutants (H415W and T508K) for an additional 10 h modification. The physicochemical properties of the modified starch were determined by scanning electron microscopy and X-ray diffraction, etc. The results demonstrated that the dual enzyme treatment decreased rapid digestibility by 23.07 % and retrograde enthalpy by 5.51 J/g compared to NCS. This study provides guidance for the industrial enzymatic preparation of highly branched starch.
生麦芽α-淀粉酶（MA，EC 3.2.1.133）具有很高的热稳定性，能切割由α-1,4糖苷键连接的长淀粉链。而糖原分支酶（GBE，EC 2.4.1.18）能增加淀粉的分支程度。在高温下，温度升高会增强淀粉的溶解性，提高MA和GBE对葡聚糖链的可及性。因此，首先将未糊化的普通玉米淀粉（NCS）乳液（20% w/w，干基）在70℃下用α-淀粉酶（MA）预处理2小时，然后使用嗜热栖热菌OT3 GBE突变体（H415W和T508K）进行额外10小时的酶促修饰。通过扫描电子显微镜和X射线衍射等方法测定了改性淀粉的理化性质。结果表明，与NCS相比，双酶处理使快速消化率降低了23.07%，回生焓降低了5.51 J/g。本研究为高支链淀粉的工业酶法制备提供了指导。
