Anotace:
Rice is considered as a staple food, which approximately half of the world population consumes. However, it is apparent that rice surplus and low price problem still remain. Consequently, instant rice has been promoted in order to tackle with the present issue and open more choices to the consumers. The current problem of commercial instant rice is slow rehydration and poor quality. This research focused on the rice cooking methods to improve the quality of instant rice dried by industrial microwave oven. Four cooking methods were investigated: Boiling in a pressure cooker (BPC), Steaming in a pressure cooker (SPC), Boiling water method (BL) and Steaming method (SM). The industrial microwave oven (6,400 watt, 2,450 MHz) was used to dry the cooked rice in each treatment to the moisture content lower than 14% (w.b.). The results showed that the hardness, stickiness and whiteness of rehydrated rice cooking by different methods had no significant difference with freshly cooked rice. BPC method is the recommended method for instant rice processing since it could provide more porous structures after drying, which relate to fast rehydration for 3 minutes in boiling water and better quality. Furthermore, after rehydration process, the grain appearance was pretty good and did not stick together. Therefore, this knowledge can be applied for the instant rice production at the industrial level.