Effect of dry and wet millings on physicochemical properties of black rice flours

The physicochemical properties of black rice flours produced from dry and wet milling were carried out to investigate their applications in food processing industry. The dry milled black rice flours showed lower fat, protein, ash, and anthocyanin contents than those of wet milled black rice flours with no effect due to number of millings. Average particle sizes (379~288 μm) of dry milled flours were bigger than those (336~253 μm) of wet milled flours. Particles with 60 mesh or more increased with increasing milling times. Wet milled flours had higher damaged starch, water solubility index (WSI), and water absorption index (WAI) compared to dry milled flours. Pasting properties measured by rapid visco analyzer (RVA) resulted in higher pasting temperatures in dry milled flours (62.5~69.4°C) than wet milled flours (46.1~46.4°C). As the number of milling times increased, pasting temperature of wet milled flours were not effected. Dry and wet milling resulted in reduced trough, final viscosity, and consistency with increasing milling times.