Abstract The difference between superior grains (SG) and inferior grains (IG) is an important factor that directly determines rice yield and quality. In this study, four varieties with different amylose contents were used to examine differences in the starch structure, physicochemical and functional properties as well as texture characteristics between SG and IG. A higher amylose content (AAC), long chain (degree of polymerization ≥ 37) content, average degree of polymerization, and larger granule size were observed in SG, while the short chain (DP 6–12) content and relative crystallinity showed the opposite result. This resulted in a lower swelling factor, higher gelatinization temperature, retrogradation tendency and harder texture in SG. SG were found to have higher slowly digestible starch (SDS) and resistant starch (RS) contents compared with IG, which means a better functional properties. This study indicated that higher amylose and long-chain amylopectin contents in SG probably degrades the rice eating and cooking qualities but improves functional properties as compared with IG.

中文翻译：

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不同直链淀粉含量水稻品种优劣粒淀粉结构、理化性质和质构特征的差异

摘要 优粒（SG）与劣粒（IG）的差异是直接决定水稻产量和品质的重要因素。在这项研究中，使用具有不同直链淀粉含量的四个品种来检查 SG 和 IG 在淀粉结构、理化和功能特性以及质地特征方面的差异。在SG中观察到更高的直链淀粉含量（AAC）、长链（聚合度≥37）含量、平均聚合度和更大的颗粒尺寸，而短链（DP 6-12）含量和相对结晶度则相反结果。这导致 SG 具有较低的溶胀系数、较高的糊化温度、回生倾向和较硬的质地。发现SG与IG相比具有更高的慢消化淀粉（SDS）和抗性淀粉（RS）含量，这意味着更好的功能特性。该研究表明，与 IG 相比，SG 中较高的直链淀粉和长链支链淀粉含量可能会降低大米的食用和烹饪品质，但会改善功能特性。