Modeling the Drying of Soybean Curd Residue Based Fish Feed
T. T. Ayanlade *
Department of Agricultural Engineering, Federal University of Technology, P.M.B. 704, Akure, Ondo State, Nigeria.
J. A. Adegboyega
Department of Agricultural Engineering, Federal University of Technology, P.M.B. 704, Akure, Ondo State, Nigeria.
A. P. Olalusi
Department of Agricultural Engineering, Federal University of Technology, P.M.B. 704, Akure, Ondo State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
The drying characteristics of Soybean curd residue (SCR) based fish feed were investigated using an oven at temperatures of 40, 50, 60, 70 and 80°C, and at a constant air velocity of 1.5 m/s. The ingredients composition for the fish feed were mixed and extruded using a single screw extruder. Then, the extruded fish feeds were dried in an oven at the various temperatures. The coefficient of determination (R2), Root Mean Square Error (RSME) and reduced chi-square (χ2) between the observed and predicted moisture ratio for all conditions of drying were used to study and evaluate the performance of the nine models fitted to the data gotten from the experimentation. Page model was the best for SCR based fish feed samples dried at 60°C which is the best temperature for drying by the coefficient of determination r2, which was concluded based on the mathematical modelling of the drying characteristics. Drying at all temperatures produced the proximate composition within the desirable limit. Although, protein and fat content decreased and were highest after drying at 400C, while carbohydrate and fibre increased and were highest after drying at 80°C temperature content of the fish feed. At 60°C, proximate composition was at the medium within desirable limits which can be fed directly to Clarias Gariepinus.
Keywords: Soybean curd residue (SCR), thin layer drying models, temperature, proximate composition.