Freeze-Drying Kinetics Approach of Soluble Coffee. Mass Transfer Parameters Estimation

Abstract

ABSTRACT. The present paper presents the freeze-drying kinetics of soluble coffee in order to determine the mass transfer parameters. Several semi-theoretical and empirical models were used to find the best fit to the experimental data. The applied models were compared using the coefficient of determination (R 2 ), the mean relative percent error (P), the root mean square error (RMSE) and the reduced chi-square ( 2 ). The Midilli model was found to fit better to the experimental freeze-drying data comparative to other models. The Fick's second law was employed to determine the effective diffusion coefficient (Deff).

Vacuum-Drying of the LiNi1/3Co1/3Mn1/3O2 Cathode Material

“…Because this stage takes a long time, the falling-rate drying period is the main part in the whole drying process. Similar behaviors have been reported in other drying literature studies, for instance, olive pomace, plaster of paris, Th­(C 2 O 4 ) 2 , lime juice powder, and soluble coffee …”

“…Effective diffusivity is the material property and it can be determined using the Fick’s second law. The general solution to Fick’s equation for an infinite slab is shown in eq − where D eff is the effective diffusivity, L is the thickness of the thin layer, and n is an integer.…”

“…Similar behaviors have been reported in other drying literature studies, for instance, olive pomace, 24 plaster of paris, 28 Th(C 2 O 4 ) 2 , 33 lime juice powder, 34 and soluble coffee. 35 Drying Kinetics. The model parameters and statistical results are listed in Table 4.…”

The Influence of Temperature and Dolomite Addition on the Drying Kinetics of Sugar Beet Pulp (Beta Vulgaris L.)

“…The material so prepared was placed in a thin-layer of 8 mm, in 100 mm diameter Petri dishes and then in dryer. Gravimetric measurements were made at each 15 minute, as described in literature [15].…”