Influence of Buckwheat Flour on Physicochemical Properties and Consumer Acceptance of Steamed Bread

Buckwheat flour was incorporated into steamed breads by adding the flour in the range of 0～9% based on the Baker's percentages and the physicochemical properties and consumer acceptance were investigated. After mixing, kneading, proofing, and molding, bread dough was steamed for 15 min using a steam tray and boiling water. The samples were cooled to room temperature for 15 min and packed in airtight bags for further analyses. pH of the steamed bread decreased slightly while titratable acidity increased significantly from 1.02 to 1.37 mL with the incorporation of more buckwheat flour in the formulation (p＜0.05). Water activity was not affected by the buckwheat flour level (p＞0.05). Moisture content slightly decreased from 43.72 to 42.30% while soluble solids content increased from 0.63 to 0.85 as the buckwheat flour concentration increased. As a result of the addition of buckwheat flour, the specific volume decreased from 3.31 to 2.57 mL/g; on the other hand, the spread ratio ranged from 2.17 to 2.21 without significant differences among them (p＞0.05). At the higher level of buckwheat content, lower scores of all color parameters (L*, a*, and b*-values) were observed. Firmness increased significantly with an increase in buckwheat flour content (p＜0.05). Consumer acceptance tests indicated that incorporation of up to 3% buckwheat flour in the formulation of steamed breads did not significantly influence the consumers' acceptability in all attributes tested, except for color and elasticity.