Optimization of Rice (Oryza Sativa) Malting Process by Second-Order Experimental Design

The malting process of rice (OM4080 variety from Mekong Delta Rice Research Institute) was studied under pilot condition plan by means of the second-order experimental design. Processing parameters, such as the steeping time (0-60 hrs), steeping temperature (5-450C), germination time (0-8 days), germination temperature (5-450C) and gibberellin concentration (0-2 mg/kg) were investigated. As a result, all germination conditions, especially germination time, germination temperature, and gibberellin concentration had a significant effect on the malting loss, amylase activity and starch content. The protein content was not clearly affected by any conditions. The optimum conditions for malting process (with highest amylase activity) were as follows: 30 hrs of steeping time, 30-350 C of steeping temperature, 5-5.5 days of germination time, 250C of germination temperature, and 1.5 mg/kg of giberrellin concentration.