School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, PR China.
School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, PR China.
Int J Biol Macromol. 2020 Feb 15;145:133-140. doi: 10.1016/j.ijbiomac.2019.12.102. Epub 2019 Dec 13.
To understand the contribution of granule inner portion to the pasting property of acetylated potato starch under the electric field and ultrasonic treatment, these starches were subjected to chemical surface gelatinization by 4.0 mol/L CaCl to obtain remaining granules with pasting time 0, 6, 12, 18, 24, 30 min, respectively. The structure of remaining granule was studied by the fitted distribution curve. Their morphological change, crystal structure and thermal property were investigated with scanning electron microscopy (SEM), X-ray diffractometry (XRD) and differential scanning calorimetry (DSC). The degree of substitution was obviously improved (DS was 0.37). The distribution curve of acetyl groups and amylose content showed that acetyl groups, both amylose and amylopectin populations were unevenly distributed. A large extent of acetylation took place in the outer lamellae. The SEM presented that the remaining potato starch granules had a rough surface with a lamella structure. The XRD and DSC showed that the acetylation was confirmed to mainly occur the amorphous region and only take place in the outer lamellae of crystalline regions of starch granule. The distribution of amorphous and crystalline regions was uneven. Chemical gelatinization was a process of stepwise removal of the outer layer.
为了理解颗粒内部对乙酰化马铃薯淀粉在电场和超声处理下糊化性质的贡献，将这些淀粉用 4.0mol/L CaCl2 进行化学表面糊化，分别得到糊化时间为 0、6、12、18、24 和 30min 的剩余颗粒。通过拟合分布曲线研究剩余颗粒的结构。用扫描电子显微镜（SEM）、X 射线衍射（XRD）和差示扫描量热法（DSC）研究其形态变化、晶体结构和热性能。取代度明显提高（DS 为 0.37）。乙酰基和直链淀粉含量的分布曲线表明，乙酰基、直链淀粉和支链淀粉群体分布不均匀。大量的乙酰化发生在外壳层。SEM 显示剩余的马铃薯淀粉颗粒表面粗糙，具有层状结构。XRD 和 DSC 表明，乙酰化主要发生在无定形区，仅发生在淀粉颗粒结晶区的外壳层。无定形区和结晶区的分布不均匀。化学糊化是一个逐步去除外层的过程。
