Effects of storage and processing parameters on pasting properties of Ofada for production of boiled and mashed rice

Abstract

This study was designed to determine the effect of storage duration and processing conditions on pasting characteristics of Ofada rice and to determine the optimum pasting parameters for the production of boiled and mashed rice. The interactions of variables (storage, soaking, parboiling and drying) were studied using response surface methodology and pasting responses (final viscosity, trough, setback viscosity, breakdown, pasting temperature and pasting time) were analysed. The coefficient of R²and adequate precision ranged between 0.994–0.7374 and 26.825–5.375, respectively, which indicate good fitness of the model. Parboiling temperature, drying temperature and storage duration significantly influenced the pasting properties of grain as revealed by positive coefficients in the model. The pasting requirements for boiled rice are storage of paddy for nine months, soaking for two days and 19 h, parboiling at 90.42°C and drying at 30°C, while for mashed rice storage of paddy for one month followed by soaking for five days, parboiling at 80°C and drying at 54.22°C are required.