Moisture‐dependent engineering properties of underutilized browntop millet (unhulled and hulled) and characterization of milled flour

Abstract

Browntop millet is an underutilized indigenous cereal crop. It is termed as the nutricereal due to its superiority in terms of nutritional quality. The current study attempted to investigate the effect of moisture content (10%–27%) on properties such as physical, mechanical, aerodynamic, and textural properties of unhulled and hulled browntop millet to uncover the gaps in developing the efficient primary processing machinery. In addition, we investigated the impact of milling on the biochemical, functional, color, structural, and powder flow properties of browntop millet flour. The results revealed that as the moisture content increased, the principle dimensions, 1000 grain weight, terminal velocity, angle of repose, and static coefficient of friction were linearly increased. In the same moisture content range, characteristics such as true density, bulk density, porosity, and hardness displayed an inverse trend. Milling showed a substantial (p < 0.05) influence on the nutritional, functional and color parameters. FTIR spectra and X-ray diffraction patterns demonstrated a slight change in functional groups and a slight decrease in starch crystallinity respectively. All three millet flours were cohesive. These flours, however, exhibited a positive correlation with bulk density and a negative correlation with wall friction and effective internal friction angles as the principle consolidating stress increased. Practical Application Millets are a globally significant food crop with major economic influence in developing nations. They are one of the most significant drought-resistant crops, and a good source of health-promoting complex carbohydrates, dietary fiber, phenolic compounds, and phytochemicals. Despite of their high nutritional superiority and environmental friendliness, production and consumption have declined over the years. The significant factor contributing to this decline is the lack of machinery or equipment available to process on a commercial and residential scale after harvest. The knowledge of the measured properties will encourage researchers to develop and modernize equipment used for destoning, grading, sorting, separation, dehulling, and conveying. The measured nutritional, mineral, functional, structural, and powder flow properties of milled browntop millet fractions will help develop a new product. So that millet can be used to its full potential.