Effect of Blending Ratio and Extrusion Operating Conditions on Nutritional Quality and Functional and Sensory Acceptability of Teff‐Bulla‐Based Complementary Food: A Response Surface Methodology Approach

The purpose of this study was to identify possible locally accessible cereals, tubers, and legumes for use in the extrusion of teff, bulla, and haricot beans to prepare inexpensive supplemental foods. This study used central composite rotatable design (CCRD) to assess the effects of specific processing parameters on response variables such as proximate composition and physical, functional, and sensory qualities of produced complementary food. The processing parameters included haricot bean blending ratios (BR) (10–30%), feed moisture content (FMC) (15–21%), and barrel temperature (BT) (120–160°C). The proximate composition of the complementary food ranged from 9.25 to 12.36% moisture content, 7.82 to 14.04% protein, 2.1 to 3.28% ash, 1.13 to 3.93% fiber, 1.17 to 3.12% fat, 65.40 to 78.25% carbohydrate, and 338.42 to 354.86 kcal/100 g energy. The predominant minerals and antinutritional factors ranged from 2.40 to 10.37 mg/100 g, 58.70 to 146.26 mg/100 g, 0.8 to 4.74 mg/100 g, 113.21 to 325.00 mg/100 g, and 16.54 to 44.62 mg/100 g for Fe, Ca, Zn, phytate, and tannin, respectively. The blending ratio and extrusion parameters demonstrated significant ( p < 0.05) linear, quadratic, and interaction impacts on the physical and functional responses, according to analysis of variance (ANOVA). Mothers and caregivers largely approved all the trial porridges. The best blending and extrusion parameters, according to numerical optimization, were a BR of 28.2837%, FMC of 15.0007%, and BT of 120.001°C. The predicted responses for optimization were water solubility index (WSI) (32.4462 g/g), water absorption index (WAI) (3.69849%), viscosity (2016.47cP), protein (14.046%), and energy (348.034 kcal/100 g) with a desirability value of 0.856. This research leads us to believe that producing complementary meals with excellent nutritional value for developing nations may be achieved by evidence‐based selection of locally accessible plant‐based components.