Experimental evaluation of beef drying kinetics in a solar tunnel dryer

Abstract

This study focused on the experimental analysis on drying kinetics of beef in a solar tunnel dryer. During the drying process the parameters of drying air were monitored. Experimental drying curves were then determined. The drying data were fitted to five drying models and their constants evaluated by non-linear regression analysis. Validity of the models was assessed using the coefficient of determination (R2), the reduced chi-square (χ2), mean relative percent error (P) and root mean square error (ERMS). Effective moisture diffusivity (Deff) of beef was also determined. During the drying period, the ambient temperature, ambient relative humidity, inlet air velocity and solar radiation intensity varied from 21.3 to 38.9 °C, 48–69.5%, 0.02–0.18 m/s and 476.3–1000 W/m2 respectively. Temperature profile along the tunnel dryer increased with increased solar radiation and decreased continuously at high moisture content of beef. Whereas drying occurred predominantly in the falling rate period for both drying methods, samples dried in the solar drier had a higher drying rate compared to sun dried beef. The most suitable model for representing the drying characteristics of beef was the Page model. The Deff values for solar tunnel dried beef varied from 2.282 10−10 to 2.536 × 10−10 m/s2.