Milling and Differential Sieving to Impact Buckwheat (Fagopyrum esculentum) Flour Techno-Functional Properties and Steamed Buckwheat Cake Quality

Variations in the particle size of cereal flour could influence its techno-functional properties and affect the quality of the end products. In this study, common buckwheat (Fagopyrum esculentum) seeds were milled and then sieved into five fractions (≥200, 150–200, 100–150, 80–100, and 60–80 mesh). Proximate analysis showed that the protein and ash contents of buckwheat flour decreased with decreased particle size, whereas the starch content increased. Reducing the particle size did not change the A-type crystalline structure and the short-range ordered structure of buckwheat starch, whereas the buckwheat batter flowability, foaming properties and foam stability of the batter supernatant increased. The steamed buckwheat cakes made from ≥100-mesh flour showed a desirable appearance, cross-sectional structure, color, flavor, and texture. Pearson correlation analysis revealed that the starch content and relative crystallinity of buckwheat flour were significantly positively correlated with its pasting parameters and the textural properties (springiness, cohesiveness, resilience) and overall acceptability of steamed buckwheat cake, whereas the protein, lipid, and β-sheet content of buckwheat flour showed the opposite trend. This study demonstrated that differential sieving caused a difference in particle size and chemical composition, which were key variables governing the processing performance of buckwheat flour and important to the quality of its end products.