School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
J Agric Food Chem. 2024 Jun 5;72(22):12762-12774. doi: 10.1021/acs.jafc.4c01561. Epub 2024 May 22.
Small-granule starches (SGSs) have technological advantages over starches of conventional sizes for many applications. The study compared the granular characteristics of three SGSs (from amaranth, quinoa, and taro) with those of maize and potato starches and revealed their molecular basis. The results indicated that the supramolecular architecture of starch granules was not necessarily correlated with granule size. Acid hydrolysis of amaranth and quinoa starches was fast due to not only their small granule sizes but also the defects in the supramolecular structure, to which short external and internal chain lengths of amaranth and quinoa amylopectins contributed. By comparison, the granular architecture of taro starch granules was more stable partly due to the longer external chain length of taro amylopectin. Comparison of the molecular composition of branched subunits (released by using α-amylase of ) in amylopectins and that in lintnerized starches suggested a significant heterogeneous degradation of amaranth and quinoa starches at supramolecular levels.
小颗粒淀粉（SGS）在许多应用中比常规大小的淀粉具有技术优势。本研究比较了三种 SGS（来自苋菜、藜麦和芋头）与玉米和马铃薯淀粉的颗粒特性，并揭示了它们的分子基础。结果表明，淀粉颗粒的超分子结构不一定与颗粒大小相关。由于苋菜和藜麦淀粉的小颗粒尺寸以及短的外部和内部链长，其支链淀粉的超分子结构存在缺陷，因此酸水解速度很快。相比之下，芋头淀粉颗粒的颗粒结构更稳定，部分原因是芋头支链淀粉的外部链长更长。通过比较使用α-淀粉酶释放的支链亚基（在支链淀粉中的）的分子组成与糊化淀粉中的分子组成，表明苋菜和藜麦淀粉在超分子水平上发生了明显的不均匀降解。
