Abstract

Four formulas were prepared for production of low phenylalanine pasta suitable for phenylketonuria (PKU) patients. The formulas were based on partial replacement of wheat flour with different levels of corn starch. Pectin and carboxymethylcellulose (CMC) were added as a texture modifier. Chemical composition, amino acids, dough characteristics, color attributes, cooking quality, electron microscopic examination and sensory evaluation of pasta were investigated. The obtained results revealed that pasta samples had lower protein and phenylalanine content than control as a result of replacing wheat flour using corn starch. Phenylalanine and protein content of formula "D" which contains 66 g corn starch, 30 g wheat flour, 2 g pectin and 2 g CMC reduced by 68 and 70%, respectively, compared with control. Viscoamylograph and falling number parameters were significantly affected. The cooking loss of pasta ranged from 10.60 to 22.50% and was significantly higher than that of the control, but adding hydrocolloids (pectin and CMC) diminished cooking loss. Sensory characteristics of pasta indicated that all formulas were acceptable. Formula "D" which has the lowest phenylalanine content seems to be superior for PKU patients.

Key words: Pasta, wheat flour, corn starch, pectin, carboxymethylcellulose, phenylketonuria, amino acids, microstructure, sensory evaluation.