Effect of extrusion on protein quality, antinutritional factors, and digestibility of complementary diet from quality protein maize and soybean protein concentrate

The nutritional quality of food transcends the availability of nutrients in food to being utilizable by the consumer. In this study, a complementary diet for infants was formulated with quality protein maize, soybean protein concentrate, and cassava starch. The formulated diet was extruded and the effect of extrusion on some antinutritional factors and in vitro protein and starch digestibilities of the meals were assessed. The amino acid profile of the samples was determined while other protein quality indices were calculated. The essential amino acid index of the formulated meal ranged from 87.3 in tryptophan to 133.7 in tyrosine-phenylalanine. Protein efficiency ratio of the formulated meal ranged from 1.20 to 2.45. The calculated biological value ranged from 92.57 to 95.20%. Extrusion cooking significantly improved the in vitro protein and starch digestibilities and significantly reduced some antinutritional factors of the formulated meals. Practical applications: Adequate nutrition during infancy and early childhood is fundamental to the development of each child's full human potential. It is well recognized that the period from birth to 2 years of age is a “critical window” for the promotion of optimal growth, health, and behavioral development. Longitudinal studies have consistently shown that this is the peak age for growth faltering and common childhood illnesses. Nigeria is well endowed with adequate food supplies, however, more than one third of the children under the age of 5 are malnourished and of all deaths of children lower than 5 years of age are directly or indirectly attributable to malnutrition hence the reason for carrying out this study. Foods with balanced amino acid profile can be obtained by mixing legumes and cereal grains. Extrusion cooking utilizes the high temperature short time phenomenon which is effective for the improvement of the biological value of food.