Low-temperature aging and drying treatments of restorative rice to improve its microbial safety and texture

In this study, a commercial production stepwise method for restorative rice with high quality and microbial safety was developed. The stepwise treatment method included steaming, refrigerated aging, and low temperature drying. The soaking rice was steamed twice at 90-100 ^o C, and then, the rice was aged at 0-10 ^o C, frozen at −20 ^o C, and dried at low temperatures with 5 m/s wind speed at 1-20 ^o C and 85% relative humidity. Applying the three steps improved sensory qualities compared with the conventional hot air drying and made storage at room temperature for 3 months possible. Specifically, the moisture content of the restorative rice was increased to 30%, which was 4.3 times higher than the 7% of the conventional air dried rice, and the rice grain shape was well maintained. The texture and appearance of the three-step rice were significantly improved (p<0.05) in a sensory evaluation.