Low Phenylalanine Egyptian Shamy Bread

Four formulas were prepared for production of low phenylalanine Egyptian shamy bread suitable for phenylketonuria (PKU) patients. The formulas were based on partial replacement of first break wheat flour (low protein flour) with different levels of corn starch. Pectin and carboxymethylcellulose (CMC) were used as a texture modifier and to improve staling rate of bread. Shamy bread made of 100% first break wheat flour was also prepared for comparison. Chemical composition, amino acids content, dough characteristics, baking test, sensory evaluation and staling rate of bread were investigated. A remarkable reduction of protein, consequently, phenylalanine of bread was detected. Phenylalanine content of formula "D", which contained 66 g of corn starch, 30 g of first break wheat flour, 2 g of pectin and 2 g of CMC, was reduced by 62% compared with the control. The rheological properties of the dough were affected by starch and hydrocolloids incorporation. Sensory characteristics of bread indicated that all formulas were acceptable, but formula "D" seems to be superior for PKU patients.