Optimization of hydrothermal treatment for little millet grains (Panicum miliare)

Abstract

Hydrothermal treatment is one of the processes used to improve the milling quality of rice. Little millet is one the minor millet which is used as rice in India. The usage of little millet has been reduced because of problem in milling and higher breakage. In the present study an attempt was done to improve the milling yield and to reduce the breakage by applying hydrothermal treatment and conditions used were different soaking and steaming conditions. Whole little millet grain was soaked at different soaking temperatures of 60, 70 and 80 °C. The soaking time was 3 and 4 h followed by steaming at temperatures 100 and 110 °C for 15, 20 and 25 min. After drying, milling was done. The conditions were standardized by analyzing milling quality, cooking quality, colour values and consumer acceptability. Head rice yield was increased and breakage was decreased with increase in the soaking time, soaking temperature, steaming time and steaming temperature. Colour become darker, cooking time increased as time and temperature of soaking and steaming increased. When all other parameters considered the treatment with initial soaking temperature of 700 °C for 3 h and steaming at 1100 °C for 20 min was found to be optimum with 92.08 % head rice yield, 0.98 % broken, 17.66 min of cooking time, with 4.90 % leached solids and 3.30 g/g of water uptake. The treatment improved milling efficiency by increasing milling yield and reduced breakage.