College of Food Science and Technology, Henan University of Technology, Zhengzhou 450001, China; Institute of Physical Science and Engineering, Zhengzhou University, Zhengzhou 450001, China.
College of Food Science and Technology, Henan University of Technology, Zhengzhou 450001, China.
Int J Biol Macromol. 2020 Jun 15;153:1299-1309. doi: 10.1016/j.ijbiomac.2019.10.265. Epub 2019 Nov 20.
The objective of the present investigation was to compared the structural and functional properties of starch isolated from fresh raw Chinese yam (FYS) and the Chinese yam after freeze-drying pretreatment (FDS), after hot-air drying pretreatment (HADS), after subcritical dimethyl ether dewaterization pretreatment (SDDS). Freeze-drying (FD) process reduced the short-and long-range molecular order of Chinese yam starch. Hot-air drying (HAD) process promoted the formation of ordered structure of starch granules. SEM images displayed the presence of protein-starch complexes in the HADS and SDDS samples. The FDS had the smallest Mw of amylopectin with 4.09 × 10 g/mol, but the Mw values of amylose molecules for FYS was highest. The branch chain length of amylopectin in HADS had a smaller proportion of short chains and less long chains and higher proportion of long chains compared with other starches. These molecular structure changes caused by the various drying pretreatment processes, resulting in the difference in functional properties including solubility and swelling power, gelatinization parameters, pasting characteristics and rheological properties. This study provided important information for the suitable application of starches isolated from various dried Chinese yam.
本研究的目的是比较鲜生山药（FYS）和经冷冻干燥预处理（FDS）、热风干燥预处理（HADS）、亚临界二甲醚脱水预处理（SDDS）后的山药淀粉的结构和功能特性。冷冻干燥（FD）过程降低了山药淀粉的短程和长程分子有序性。热风干燥（HAD）过程促进了淀粉颗粒有序结构的形成。SEM 图像显示 HAD 和 SDDS 样品中存在蛋白质-淀粉复合物。FDS 具有最小的支链淀粉Mw（4.09×10⁵g/mol），但 FYS 的直链淀粉Mw 值最高。与其他淀粉相比，HADS 中支链淀粉的短链比例较小，长链比例较大。这些由各种干燥预处理过程引起的分子结构变化，导致了功能特性（包括溶解度和膨胀力、糊化参数、糊化特性和流变特性）的差异。本研究为不同干燥山药淀粉的适宜应用提供了重要信息。
