Effect of improved parboiling methods on the physical and cooked grain characteristics of rice varieties in Benin

The efficiency of traditional, intermediate and improved parboilers was compared through their effects on certain physical and cooking quality traits. Two varieties (NERICA 4 and Gambiaka) commonly cultivated and consumed in Benin were used. Results showed that the traditional parboiler had the highest level of heat-damaged grains (90%) with the improved equipment having the least (17%). The improved and intermediate parboiling technology produced grains of comparable hardness (4 kg and 6 kg, respectively, for Gambiaka and NERICA 4) while the traditional method resulted in a sample with the least hardness for both Gambiaka (4 kg) and NERICA 4 (3 kg). The improved method and the intermediate technology using wooden sticks at the bottom of the vessel had higher water uptake (2.97 ml/grain) and grain swelling ratios (5.41) as compared to the traditional and intermediate methods using a container with a perforated bottom.