Ohmic heating parboiling as a novel pretreatment to enhance the milling properties of Kodo millet

Abstract

Dehulling of Kodo millet is difficult due to compact husk and small size. Pretreatment before milling has been shown to increase grain hardness and minimize milling loss. Ohmic heating (OH), a novel thermal technique could be employed for parboiling of Kodo millet to enhance the milling properties of millet. A study was conducted to evaluate the effect of ohmic heating parboiling (OP) on milling, physical properties, and nutritional composition of Kodo millet and compared it with conventional parboiling (CP). Kodo millet was soaked at 50°C, 60°C, and 70°C for 5 h, 2.5 h, and 1.5 h respectively to attain a moisture content of 30%. The soaked millet was parboiled for 20 min at a voltage gradient of 14 V/cm. Results showed that this treatment when compared to CP, was found to have higher hardness, head grain yield (HGY), and dehulling efficiency. HGY increased by 22.69% in CP and 28.03 % in OP, however, with an increase in the soaking temperature, HGY increased by 5.19-5.49%. A significant decrease was observed in the broken percentage. OP affected the nutritional profile as it retained higher protein than CP. This indicates that OP is superior in enhancing the milling properties of parboiled millet.