Mathematical Modeling of Hot Air Drying of Spinach Leaves in Universal Hot Air Oven

The objective of this study was to develop a model for drying characteristic curve of Spinach in Universal Hot Air Oven .Drying experiment were conducted using a constant air velocity2.2m/s and three drying air temperature of 55, 65, and75 o C with two pretreatment conditions and load densities that are given respectively condition (Blanched and Unblanched) load density (3kg/m 2 , 3.5 kg/m 2 ).The drying rate increased with increased in temperature and decrease with increase in time. Pretreatment and load densities had an insignificant role on drying rate. The experimental drying data of spinach applied to four moisture ratio models, namely, page l, modified page, generalized exponential, and two term models. Nonlinear regression analysis performed to relate the parameters of the model with the drying conditions. The performance of these models evaluated by comparing the coefficient of determination, R 2 , and reduced chi-square, χ 2 , between the observed and predicted moisture ratio. Among all these model page model was found to be best describe the drying behavior of spinach leaves .the standard error of estimation was least(0.004-0.031) as well as coefficient of determination (R 2 )was highest (0.991-1) in page model as compared to other models.