Effects of Extrusion Cooking Variables on the Proximate Composition of Extruded Snacks from Blends of Cocoyam and Bambara Nut Flours

Abstract

Flour blends of cocoyam and Bambara groundnut were produced through extrusion cooking. Response Surface Methodology (RSM) Central Composite Rotatable Design (CCRD) was adopted for the formulations. Association of Analytical Chemist procedure was used to determine the proximate composition. The main objective was to determine the effects of the processing variables; feed blend composition (X1), barrel temperature (X2), and feed moisture content (X3), on Snacks and the proximate composition (moisture, protein, lipids, fibre, ash, and carbohydrate) of the extrudate. The analysis of variance (ANOVA) showed a significance (p< 0.05) of the models fitted in describing the relationship between the input and output in its natural state. There was a non-significant lack–of–fit test. The result of the moisture showed that the model X1, X2, (linear) X12, X2 2, (quadratic) were all significant (P ≤0.05) while the interactive terms X12, X22, X32, had an anta gonistic relationship at (P <0.05). An upward increase in moisture at the linear and quadratic levels will positively affect the product quality. Moisture content ranged between 2.65 to 4.02%, protein content ranged between 3.40 to 7.01%, the ash content ranged from 1.36mg/100g to 2.33mg/100g, the fibre content varied between 0.18mgand100 to 1.94mg/100g, The ANOVA showed that the processing variables were significant (P< 0.05).