Effect of Cooking and Drum Drying on the Nutritive Value of Sorghum-Pigeon Pea Composite Flour

Abstract

The study was conducted to evaluate changes during cooking and drum drying on the chemical composition, amino acids composition, amino acids scores and digestibility of sorghum-pigeon pea composite flour. Both cooking and drum drying in the presence of 1% ascorbic acid were found to improve the energy value of the final products and the in-vitro protein digestibility of sorghum-pigeon pea composite flour significantly (p<0.05). In fact, drum drying without pre-cooking slightly increased the protein digestibility of the composite flour from 76-77%, while pre-cooking before drum drying of the composite flour increased the protein digestibility of the drum-dried product to about 80%. Drum drying after pre-cooking reduced lysine and methionine levels by 3.5 and 22.5%, respectively. Also, drum drying significantly (p<0.05) decreased the fat content in the two drum dried products (with or without pre-cooking). Moreover, drum drying without pre-cooking increase the ash content while the ash decreased when sorghum-pigeon pea composite flour was drum dried after cooking.