Improving Instant Rice Quality by Novel Combined Drying

The quality parameters of a new type of instant rice with higher moisture content and lower water activity (a(w)) were investigated. The product was obtained after combining three types of drying processes as follows: air drying, microwave drying, and osmotic process. The new-type instant rice was evaluated by comparing it with freeze drying (FD), hot-air drying (AD), and freshly cooked rice. Several quality parameters were discussed, including color, texture, water molecule mobility, microstructure, flavor, and sensory. The comparison showed that the yellowness, hardness, and chewiness of the new-type instant rice had no significant difference with cooked rice, and it had better color and texture than FD and AD. Meanwhile, it showed much lower water molecule mobility and distinguished microstructure. In addition, the flavor and reconstituted sensory characteristic of the new instant rice were more similar to those of freshly cooked rice. In summary, the new instant rice ensured acceptable quality, and could be produced as a new form of instant rice.