Abstract Crystallized debranched waxy rice starch had higher resistant starch (RS) content and crystallinity than crystallized debranched normal rice starch. Thus, debranched waxy rice starch (Unf) with molecular-weight dispersity (DM) at 2.161 was fractionated into F1, F2 and F3 with the DM at 1.604, 1.466 and 1.658, respectively. Moreover, the peak molecular weight of Unf, F1, F2 and F3 was 3.146e + 03, 2.906e + 03, 3.585e + 03, and 4.178e + 03 Da, respectively. Obviously, Unf had higher molecular weight but wider distribution than F1. After crystallization, Unf and F1 had similar RS content and crystallinity. Similar phenomenon occurred to F2 and F3. These results suggested that narrowing molecular weight distribution promoted crystallization of starch and improved its resistance. To further improve efficiency of preparing RS by crystallization, crystallization of F3 was optimized. Under the optimal conditions, the yield and RS content of crystallized F3 reached 81.2% and 80.6%, respectively.

中文翻译：

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通过缩小分子量分布提高结晶淀粉的抗性

摘要 结晶脱支糯米淀粉比结晶脱支普通大米淀粉具有更高的抗性淀粉(RS)含量和结晶度。因此，分子量分散度 (DM) 为 2.161 的脱支糯米淀粉 (Unf) 被分馏为 F1、F2 和 F3，DM 分别为 1.604、1.466 和 1.658。此外，Unf、F1、F2 和 F3 的峰值分子量分别为 3.146e + 03、2.906e + 03、3.585e + 03 和 4.178e + 03 Da。显然，Unf 比 F1 具有更高的分子量但分布更广。结晶后，Unf 和 F1 具有相似的 RS 含量和结晶度。F2和F3也出现了类似的现象。这些结果表明，缩小分子量分布促进了淀粉的结晶并提高了其抗性。为了进一步提高结晶制备 RS 的效率，F3 的结晶得到优化。在最佳条件下，结晶F3的收率和RS含量分别达到81.2%和80.6%。