Characterizing whole-wheat flours produced using a commercial stone mill, laboratory mills, and household single-stream flour mills:

Abstract

Background and objectives: One hard wheat and one semi-hard wheat were milled on commercial, laboratory, and household-scale flour mills with rotating elements ranging from 0.1 to 1.0 m in diameter and speeds ranging from 65 to 40,000 rpm. The aim of the study was to assess and compare the quality of the flour from each of mills. Findings: Pasting viscosities, Farinograph development time and stability, and loaf volumes (LVOL) were all markedly influenced by whole-wheat flour particle size, which differed markedly between mills. LVOLs were acceptable using the flours produced by all the mills. Best flour quality came from the three mills that produced the finest whole-wheat flour. Of these, the superior flour came from the 1.0-m-diameter Osttiroler stone mill. This mill produced whole-wheat flours with more optimal levels of starch damage and higher water absorption than did the smaller mills. There was no evidence of degradation of gluten functionality even at a flour temperature of 51°C. Conclusions: The mill used affected almost all flour quality traits. However, the characteristics of the wheat applied to the mill were the dominant influence on flour functionality. Starch damage may better indicate milling severity than the heat generated during the milling process. Significance and novelty: This is the only study, that we know of, on the comparative performance of household-scale flour mills. The study also presents an alternative way of visualizing particle size distributions of flours.