Optimization of blending ratios of germinated cowpea and extrusion parameters on physical, functional, mineral, and anti-nutritional content of Ethiopian emmer wheat-based snack food

Abstract

Childhood malnutrition in Ethiopia, exacerbated by limited access to affordable, nutrient-rich foods, particularly zinc and iron, was addressed in this study. This study explores the optimization of extrusion parameters and blending ratios of emmer wheat and germinated cowpea to produce nutrient-dense, functional snacks. Using a Box-Behnken design, the effects of cowpea ratio (10–25 %), barrel temperature (80–120 °C), and feed moisture (22–26 %) were analyzed. Results revealed significant improvements in physical properties, such as radial expansion and bulk density, alongside enhanced functional traits like water absorption and solubility indices. Mineral analysis indicated increased iron and zinc content, while anti-nutritional factors like phytic acid and tannins were reduced due to optimized extrusion conditions. The interaction between barrel temperature and blending ratio was crucial in reducing phytic acid levels, supported by thermal hydrolysis and enzymatic activity. Optimal conditions included 16.74 % cowpea, 120 °C barrel temperature, and 22 % feed moisture, achieving snacks with a composite desirability rating of 0.90. This study highlights the potential of emmer wheat-cowpea extrudates as affordable, nutrient-rich solutions to combat malnutrition. These extruded snacks offer a promising solution for addressing micronutrient deficiencies while maintaining desirable sensory and functional qualities. Optimal conditions achieved balanced nutrient profiles, making these snacks suitable for addressing childhood malnutrition and promoting food security in Ethiopia.