Experimental Investigation of Suitable Soaking Temperature for Producing Parboiled ‎Jasmine Rice without Steaming

Nowadays, parboiled rice production has three primary steps comprise of soaking, steaming, and drying.  During the steaming process, rely on the steam boiler and piping process.  Paddy grain is gelatinized by saturated steam.  This part is complicated to control pressure and temperature following setting conditions, which means elaborate to operate.  This research is considered without using steaming process by soaking paddy grain with high temperature to find the best condition in temperature and soaking time for paddy grain soaking process.  After that, paddy grains are drying with hot air fluidized bed dryer. Recognize by moisture content after soaking, degree of gelatinization and head rice yield.  The soaking process has three conditions composed of 65 70 and 75°C and the hot air temperature is 150°C with a velocity of 3.5 m/s respectively for the drying process.  Drying wet paddy by 400 g per round with different drying times (10, 20, 30 seconds and 1, 2, 3 minutes).  We found that Soaking paddy with a temperature of 75°C for 4 hours is suitable because the moisture content in paddy grain is greater than soaking with 65 and 70°C.  Moisture content in paddy grain can increase to 50±2% dry basis (d.b.) After drying grain with hot air, 150°C degrees of gelatinization can reach 100%, and head rice yields around 70%.