State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China.
Joint International Research Laboratory of Agriculture and Agri-Product Safety, College of Agriculture, Yangzhou University, Yangzhou, Jiangsu Province 225009, China.
Carbohydr Polym. 2017 Nov 1;175:265-272. doi: 10.1016/j.carbpol.2017.07.084. Epub 2017 Jul 31.
Pregelatinized starch was made from indica rice starch using a so-called "improved extrusion cooking technology" (IECT) under 30%-70% moisture content. IECT-pregelatinized starch (IPS) had higher water solubility and water absorbability compared to native starch at low temperature. For pasting properties, the breakdown and setback viscosities of IPS were significantly (p<0.05) lower than native starch, suggesting improved gel stability and reduced short-term retrogradation. The rice starch granules lost their integrity in IPS, and formed a honeycomb-like structure with increased moisture content in the raw material. These properties can be explained in terms of molecular structural features, particularly the large reduction in the size of molecules, but without significant changes in the chain-length distributions of amylopectin component, and no significant change in amylose fraction. These results indicate that IECT is suitable for preparing IPS with desirable water solubility and gel stability properties.
预糊化淀粉是由籼米淀粉采用所谓的“改良挤压蒸煮技术”（IECT）在 30%-70%水分含量下制成的。与天然淀粉相比，IECT-预糊化淀粉（IPS）在低温下具有更高的水溶性和吸水性。就糊化特性而言，IPS 的破裂和回生粘度明显（p<0.05）低于天然淀粉，表明凝胶稳定性提高，短期回生减少。IPS 中的大米淀粉颗粒失去了完整性，形成了具有蜂窝状结构的物质，原料中的水分含量增加。这些特性可以从分子结构特征来解释，特别是分子尺寸的大幅减小，但支链淀粉成分的链长分布没有明显变化，直链淀粉部分也没有明显变化。这些结果表明，IECT 适合用于制备具有理想水溶性和凝胶稳定性的 IPS。
