Abstract:

Quality properties of commercial japonica rice, indica rice, and glutinous rice were investigated using general cooking and tasting evaluation methods. Meanwhile, viscosity properties of flour pastes from three kinds of commercial rice were determined using a Brabender Micro Visco-Amylograph analyzer. Results indicated that japonica rice had the best quality properties and taste attribute, glutinous rice took second place, and the quality properties and taste attribute of indica rice were the worst. Japonica rice also exhibited the lowest peak viscosity and breakdown rate. However, its gelatinization temperature, final viscosity and retrogradation value were between indica rice and glutinous rice. For glutinous rice, peak viscosity and breakdown rate were both the highest, while the lowest gelatinization temperature, final viscosity and retrogradation value were observed. In contrast, although indica rice exhibited middle levels of peak viscosity and breakdown rate, it had the highest gelatinization temperature, final viscosity and retrogradation value. The above results demonstrate that indica rice has the largest gel strength and is prone to aging, whereas, glutinous rice exhibits an opposite character. Thus, glutinous rice is sensitive to shear force and heating.

Key words: japonica rice, indica rice, glutinous rice, quality properties, pasting characteristics