doi: 10.17113/ftb.54.02.16.4304
Development of a New Model for Mass Transfer Kinetics of Petals of Echium amoenum Fisch. & C.A. Mey. under Fluidized Bed Conditions
Fatemeh Nadi*
Department of Agricultural Machinery Mechanics, Azadshahr Branch, Islamic Azad University, Shahid Rajaee St., 49617-89985 Azadshar, Iran
Article history:
Received June 19, 2015
Accepted December 4, 2015
Key words:
new thin-layer drying model, fluidized bed dryer, Echium amoenum petals, mass transfer kinetics, total phenolic content, optimum drying conditions
Summary:
A new semi-theoretical thin-layer model of the fluidized bed drying of Echium amoenum Fisch. & C.A. Mey. petals has been developed. Experiments were conducted under different conditions: temperatures of 40, 50 and 60 °C, and air velocities of 0.5, 0.75 and 1.0 m/s, until the moisture content decreased to 0.04–0.06 kg of water per kg of dry matter. Drying processes in the fluidized bed were completed in between 55 and 465 min, with minimum drying time required at the maximum temperature of 60 °C and air velocity of 1 m/s. The comparison of the new model developed here with sixteen previously published theoretical, semi-empirical or empirical thin-layer drying equations shows that using the new model the highest coefficient of correlation, the lowest reduced chi-square and root mean square error were obtained. The highest retention of total phenolic compounds in E. amoenum petals was achieved when drying at 60 °C and 1.0 m/s.
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