一步法反应挤出法化学修饰大米淀粉的结构变化。
Structural changes of chemically modified rice starch by one-step reactive extrusion.
机构信息
The State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China.
出版信息
Food Chem. 2019 Aug 1;288:354-360. doi: 10.1016/j.foodchem.2019.03.017. Epub 2019 Mar 8.
Structural changes of chemically modified rice starch (CMRS) by one-step reactive extrusion (REX) via esterification, acetylation, hydroxypropylation, and cross-linking or dual-modification (hydroxypropylation-cross-linking and acetylation-cross-linking) were investigated. REX treatments exhibited a significant effect on the structure of rice starch granules, resulting in the destruction of the starch crystalline structure and formation of new crystalline complexes. The original A-type crystalline structure was transformed to V-type after REX treatments, which were further confirmed by DSC experiments since a new endotherm at 100-122 °C was detected. Due to the susceptibility differences in shear-induced breakdown of amylopectin and amylose, the molecular degradation was heterogeneous and retarded by esterification but enhanced by cross-linking. Morphology analysis showed that the original starch granular structure was lost and replaced with a rougher and more irregular structure. In consequence, REX process exerted significant influences on rice starch granules which enhanced its resistance to enzyme hydrolysis.
采用一步法反应挤出（REX）对酯化、乙酰化、羟丙基化、交联或双重改性（羟丙基化交联和乙酰化交联）的化学改性大米淀粉（CMRS）的结构变化进行了研究。REX 处理对大米淀粉颗粒的结构有显著影响，导致淀粉结晶结构的破坏和新结晶复合物的形成。REX 处理后，原有的 A 型结晶结构转变为 V 型，这通过 DSC 实验进一步得到证实，因为在 100-122°C 检测到了新的吸热峰。由于剪切诱导的支链淀粉和直链淀粉断裂的敏感性差异，分子降解是不均匀的，酯化会使其减缓，而交联会使其加速。形貌分析表明，原有的淀粉颗粒结构丢失，取而代之的是更粗糙和不规则的结构。因此，REX 工艺对大米淀粉颗粒产生了显著影响，增强了其对酶水解的抵抗力。
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