MATHEMATICAL MODELING OF DRYING KINETICS OF GUNDRUK

Abstract

Gundruk prepared from Rayo saag (Brassica juncea) was dried at was dried at 50, 55 and 600C air temperatures in cabinet drying and under Solar and Sun drying for modeling purpose. Moisture ratio of gundruk during drying was calculated and the data obtained tests were applied to 5 well-known semi-theoretical and empirical mathematical models of drying. Model constants and coefficients were determined by nonlinear regression method. All the models were validated using statistical parameters namely; R2, RMSE, 2 χ and SSE. Experimental result showed drying of gundruk falls in falling rate period. The rate of drying continuously decreased as drying proceeds. Graphical and statistical analysis of result showed that, Midilli model was best-fitted model for cabinet drying and logarithm was best-fitted for solar drying at both day-1 and midilli for day-2 with the higher value of value of R2, and lower values of RMSE, 2 χ and SSE. The value of effective moisture diffusivity found is lowest for sun drying i.e. 1.0233×10-9 m2/s and is highest for cabinet drying at 600C i.e. 9.1708×10-9 m2/s. This shows that effective moisture diffusivity value increases with increase in drying temperature. The activation energy, which is an indicator of minimum energy required to remove moisture from a solid matrix was found to be 67.737 kJ/mol and the diffusivity constant Do was found to be 391.075 m2/s.