THE POSSIBILITY OF USING UNGERMINATED AND GERMINATED BROWN RICE FLOURS AT DIFFERENT SUBSTITUTION LEVELS OF WHEAT FLOUR IN BREADMAKING

This study was performed to investigate the possibility of using the brown or germinated brown rice flour at different substitution levels of wheat flour for soft bread (Toast) making, evaluate the quality of produced bread and know the optimal substitution levels for producing high quality bread. Chemical composition, some nutrients and amino acids of wheat flour 72%, ungerminated and germinated brown rice flours were determined. Pasting characteristics of starch and farinograph of dough were measured. In addition, sensory characteristics of prepared bread were evaluated. The obtained results indicated that ungerminated and germinated brown rice contain lipids, crude fiber, ash and reducing sugars higher than those of wheat flour. They contain higher contents of potassium and iron but lower contents of sodium and magnesium than those of wheat flour. In addition, they contain all essential and non-essential amino acids. Total essential amino acids of ungerminated brown rice (39.81%) and germinated brown rice (40.99%) were very higher than that of wheat flour 72% (25.03%). Pasting characteristics measurements showed that wheat flour starch has gelatinization temperature and viscosity at 95 ^oC lower but it has setback higher than ungerminated and germinated brown rice starches. Germinated brown rice starch has low breakdown and high setback compared with ungerminated brown rice. The results of farinograph indicated that using ungerminated or germinated brown rice caused decreasing the development and stability time but increasing the weakness of the dough, especially for ungerminated brown rice. Sensory characteristics of produced bread revealed that the effect of ungerminated or germinated brown rice on the flavor and texture (crump and crust) was very little, while its effect on the color (crump and crust) and mouth satisfaction was somewhat remarkable but all changes were in the acceptable limits. Germination process of brown rice improved its nutritional value and quality attributes of bread therefore, the using of germinated brown rice is more suitable for making of bread (Toast) than ungerminated brown rice.