Effect of hydrothermal pre-treatment on dehulling and nutritional characteristics of Kodo millet

Kodo millet ( Paspalum scrobiculatum ) is a minor millet with high nutritional properties and exhibits exceptional drought-tolerance and insect-resistance. But, the processing of this millet offers considerable challenges due to the presence of thick layers of hull. Hydrothermal pre-treatment before milling has been reported to reduce grain fragility and nutrient loss. The current study aims to assess the effect of hydrothermal pre-treatments on the dehulling, polishing, and nutritional characteristics of kodo millet. The grains were subjected to soaking (4, 6 & 8 h), steaming (10 min), and drying (till 12% moisture content) before polishing. The hydrothermally treated grain is polished by applying shearing and abrasion forces sequentially. The number of shearing passes (2, 4 & 6), and abrasive polishing time (20, 40 & 60 s) has been varied. Multivariate analysis has also been carried out to understand the correlation between different process variables. Results demonstrated that the treatment conditions significantly affect the dehulling and polishing efficiencies and the nutritional compositions of the grain. The increase in shearing and abrasion action increased the dehulling and polishing efficiencies, respectively. The study’s findings could potentially be installed to increase the dehulling and polishing efficiencies while reducing grain losses.