Convective air drying of brown seaweed Bifurcaria bifurcata in thin layer configuration

Abstract

Air drying kinetics of Bifurcaria bifurcata brown seaweed at 35, 50, 60 and 75°C were determined. Experimental drying data were modelled using two-parameter Page model (n, k). Page parameter n was constant (1.28) at tested temperatures, but k increased significantly with drying temperature from 35 to 60ºC and was invariant at higher temperatures (up to 75ºC). Drying experiments allowed the determination of the critical moisture content of seaweed (1.6 ± 0.2 kg water (kg d.b.)−1). Mass transfer coefficients during constant drying rate period and effective coefficients of water diffusion during falling drying rate period were evaluated, assuming cyclindrical geometry and considering volumetric shrinkage. Keywords: algae, diffusivity, drying kinetics, modelling, shrinkage