Effect of modification with 1,4-α-glucan branching enzyme on the rheological properties of cassava starch
Effect of modification with 1,4-α-glucan branching enzyme on the rheological properties of cassava starch
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DOI：
10.1016/j.ijbiomac.2017.05.045
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发表时间：
2017-10-01
影响因子：
8.2
通讯作者：
Li, Zhaofeng
中科院分区：
文献类型：
--
作者：
Li, Yadi;Li, Caiming;Li, Zhaofeng
采用稳态和动态剪切实验研究了热葡萄糖苷地杆菌STB02中1,4- α -葡聚糖分支酶（GBE）修饰的木薯淀粉的流变学特性。GBE处理降低了木薯淀粉糊的滞回圈面积、活化能（Ea）值和流变模型参数。此外，GBE处理增加了其存储（G′）和损耗（G′）模量，降低了它们的tan δ （G′/G′之比）值和频率依赖性。扫描电镜研究表明GBE对淀粉颗粒的选择性和特异性攻击，x射线衍射分析表明GBE处理使直链淀粉和支链淀粉的结构发生了显著变化。这些变化表明，GBE改性产生的木薯淀粉具有更结构化的网络和更好的机械加工稳定性。差示扫描量热分析和温度扫描表明，随着GBE处理时间的增加，颗粒破裂的抵抗能力增强，凝胶刚性提高，初始构象有序率大幅下降。流变学参数的显著变化表明GBE改性提高了木薯淀粉的稳定性和在食品加工工业中的适用性。(C) 2017 Elsevier B.V.版权所有
Steady and dynamic shear measurements were used to investigate the rheological properties of cassava starches modified using the 1,4-alpha-glucan branching enzyme (GBE) from Geobacillus thermoglucosidans STB02. GBE treatment lowered the hysteresis loop areas, the activation energy (Ea) values and the parameters in rheological models of cassava starch pastes. Moreover, GBE treatment increased its storage (G') and loss (G") moduli, and decreased their tan delta (ratio of G"/G') values and frequency-dependencies. Scanning electron microscopic studies showed the selective and particular attack of GBE on starch granules, and X-ray diffraction analyses showed that GBE treatment produces significant structural changes in amylose and amylopectin. These changes demonstrate that GBE modification produces cassava starch with a more structured network and improved stability towards mechanical processing. Differential scanning calorimetric analysis and temperature sweeps indicated greater resistance to granule rupture, higher gel rigidity, and a large decrease in the rate of initial conformational ordering with increasing GBE treatment time. Pronounced changes in rheological parameters revealed that GBE modification enhances the stability of cassava starch and its applicability in the food processing industry. (C) 2017 Elsevier B.V. All rights reserved.