Development of a low-moisture-content storage system for brown rice: Storability at decreased moisture contents

Airtight storage of brown rice with a low moisture content was tested and evaluated as an alternative to refrigerated storage. Brown rice samples (500 g each) at 16.2%, 14.4%, 12.8%, and 11.0% moisture contents (m.c.w.b.) were stored in plastic bottles for 6 months at 15 and 25 °C. Germination rate, fat acidity, and microbial growth were measured every month during the storage term to evaluate the effect of decreasing moisture content on storability of rice. The germination rate of brown rice with 16.2% m.c.w.b. at 25 °C declined from 97% to 27%, but for rice with less than 12.8% m.c.w.b. at 25 °C germination was above 90%. In addition, no significant difference was observed in the fat acidity of brown rice with 11.0% and 16.2% m.c.w.b. at 25 and 15 °C, respectively. Moulds were observed on the rice with more than 14.4% m.c.w.b. at 25 °C, but no mould was observed on rice with less than 12.8% m.c.w.b. From these results it is suggested that low-moisture-content storage could be as effective as low-temperature storage.