Parboiling brown rice using super heated steam fluidization technique

Abstract

This research is a study of parboiling of brown rice using superheated steam fluidization technique. The influence of soaking temperature and time, steaming temperature, and bed depth on qualities of product: head rice yield, white belly, whiteness, and viscosity of rice flour were focused. The experiments were set up at the material initial moisture content of 12.8% dry basis (d.b.), soaking temperatures of 70–90 °C, soaking times of 0.5–2.0 h., steaming temperatures of 120–160 °C, velocity of 3.9 m/s and bed depths of 8–12 cm. The experimental result showed that gelatinization occurred while product moisture content decreased and final moisture content about 28% d.b. gave the acceptable levels of the whiteness and white belly. The final moisture content lower than 28% and 18% d.b. resulted in the lower percent of head rice yield and whiteness, respectively. Considering white belly, it was found that the white belly decreased with increasing drying time. Additionally, peak viscosity, breakdown viscosity and setback viscosity of rice flour were found lower than those of raw rice.