Drying Kinetics of Indigenous Fermented Foods of the Himalaya region (Gundruk, Sinki, and Maseura)

Abstract

Indigenous fermented foods Gundruk (fermented mustard leaves), Sinki (fermented radish taproot), and Maseura (fermented lentils) are mostly sun dried, and thus often deteriorate during the uncontrolled drying process. Herein, cabinet drying was done at 50, 55, and 60°C after fermentation, and the moisture loss was systematically recorded. The data were converted to moisture ratio and fitted to five semi-theoretical drying mathematical models: Modified Henderson and Pabis, Logarithmic, Two-Term, Midilli et al., and Approximate diffusion. All the models were validated using statistical parameters, namely: R2, RMSE, χ2, and SSE. The Midilli et al. model gave excellent fit for all three products, with R2 greater than 0.97. The effective diffusivity values increased with an increase in air temperature for all the samples. The activation energy values were found to be 56.25, 21.63 and 15.08 kJ/ mol while the diffusivity constants were found to be 1268.51, 0.028, and 8.655× 10-3 m2/s for Gundruk, Sinki, and Maseura, respectively.