Optimization of Some Physical and Functional Properties of Extruded Soybean Crud Residue-Base Floating Fish Feed

Abstract

The effect of some extrusion factors on soybean crud residue-based floating fish feed was investigated. Extrusion was conducted at 20%, 25%, and 30% moisture content level, die size of 2 mm, 4 mm and 6 mm, and screw speed of 150 rpm, 200 rpm, and 250 rpm. Pearson square method of fish feed formulation was used to attain a 35% protein content of catfish feed protein requirement. Optimized value of extrusion factors moisture content, die size, and screw speed were 30%, 6 mm, and 150 rpm respectively and the optimized result of responses, expansion rate (ER) floatation rate (FR) sinking velocity (SV) specific mechanical energy (SME) swelling capacity (SC) water absorption index (WAI) water solubility index (WSI) hydration capacity (HC) and hydration index (HI) are 32.73%, 95.87%, 0.024 m s-1, 16.97 kJ kg-1, 1.73, 1.61, 2.76, 0.51, and 0.67 respectively. Feed moisture content and die size have the most significant effect on the physical and functional properties of the extrudate. Coefficient of determination R2 ranges from 0.65 to 0.96, lack of fit not-significant, desirability in optimization of 0.806, suggesting adequacy of research. Soybean crud residue base floating fish feed has been formed and evaluated with an outcome of high efficacy. This extruded producing model can be used for both domestic and industrial scales of catfish feed production.