利用筛分的方法将小麦粉筛分为140～160目、160～180目、180～200目、200目以上4个粒度区间，分析原粉和不同粒度区间小麦粉的基本理化特征、流变学特性，将这些小麦粉分别制作馒头，对各馒头样品的理化性质、质构特性、微观结构和感官评价进行分析。结果显示,不同粒度区间小麦粉的理化性质和流变学特性存在显著差异(p<0.05)，破损淀粉和灰分含量随着小麦粉粒度减小逐渐增加；180～200目区间小麦粉还有较高的粗蛋白和湿面筋含量，面筋指数也较高，此区间小麦粉馒头面团中结合水含量最高，其持水能力较强。随着小麦粉粒度减小，各粒度区间小麦粉所制作的馒头的白度逐渐升高，pH值和水分的差异对馒头品质影响不大。180～200目区间小麦粉馒头比容最高。质构分析发现，180～200目区间样品馒头的弹性表现最好，硬度和咀嚼性适中。扫描电镜观察发现，180～200目区间样品馒头面筋网状结构连续性良好，而原粉和200目以上区间样品的网状结构略差，含有大量孔洞，面筋结构松散。感官评价显示，在比容、风味和口感方面不同粒度区间样品馒头无明显差异，而180～200目区间样品综合得分最高，内部结构均匀，弹性好，风味好。综合以上结果，180～200目粒度区间小麦粉最适合制作馒头。

The effects of different size of wheat flour on the quality of steamed bread were studied. The wheat flour was selected into four particle size: 140-160 mesh, 160-180 mesh , 180-200 mesh and 200 mesh above. The basic physicochemical indexes and rheological properties of raw wheat flour and different particle size groups were analyzed. Steamed bread's physicochemical indexes, texture analyses, microstructure observations, and sensory evaluations of steamed bread by different particle size flour were analyzed. The results showed that the physicochemical properties and rheological characteristics of wheat flour had significant difference (p<0.05): damaged starch and ash content in wheat flour increased with the decrease of particle size; the crude protein and wet gluten content within 180-200 mesh were higher than others and its gluten index was also higher; the steamed bread dough made of 180-200 mesh wheat flour had the highest elasticity, and better water holding capacity. With the decrease of particle size, the whiteness of steamed bread increased gradually, and the differences of pH values and water contents had little effect on steamed bread quality. The steamed bread made of 180-200 mesh flour had the highest specific volume. Texture analysis showed that the elastic value of 180-200 mesh flour was the best, and its hardness and chewiness were moderate. Scanning electron microscopy observed that steamed bread made of 180-200 mesh flour had a better continuity of gluten network structure, but the network structures of raw flour and 200 mesh flour was slightly worse and contained a large number of holes and loose gluten structure. The sensory evaluation showed that no significant differences in the specific volume, flavor and taste of steamed bread of wheat flour with different particle size ranges. However, the sample of 180-200 mesh had the highest total score, and it had a homogeneous structure and excellent elasticity and flavor. The comprehensive results showed that wheat flour of 180-200 mesh was the most suitable for making steamed bread.