Effects of Surface Concentration on Drying Behavior of Carbohydrate Solutions |
| |
Authors: | Shuichi Yamamoto Teruaki Morihiro Koichi Ariyoshi Turkan Aktas |
| |
Affiliation: |
a Department of Chemical Engineering, School of Engineering Division of Applied Medical Engineering Science, Graduate School of Medicine, Yamaguchi University, Tokiwadai, Ube, Japan
b Department of Agricultural Machinery, Trakya University Agricultural Faculty, Tekirdag, Turkey |
| |
Abstract: | As the surface properties of the drying materials are very important not only for the drying rate but also for the quality change during drying, the effects of surface concentration on the drying behavior of liquid foods (sugar solutions) were investigated by isothermal drying experiments and by numerical calculation experiments. The isothermal drying experiments with gelled sugar solution systems (sucrose and maltodextrin) were carried out at various relative humidity (RH) values (RH = 0 to 84%). Separate experiments were carried out for determination of the desorption isotherms.
The isothermal drying curves of sugar solutions at RH = 0 to 51% were very similar. Numerical simulations also showed that the drying curves of these sugars at the surface concentration = 0 and 0.1 are almost the same, although the concentration distributions are different.
When a small amount of gelatin was added to sugar solutions, the drying rate decreased remarkably as the gelatin might form a thin film (skin) near the surface, and consequently the retention of ethanol increased. |
| |
Keywords: | Water activity Desorption isotherm Water diffusion coefficient Equilibrium water content Drying rate Surface concentration |
本文献已被 InformaWorld 等数据库收录! |
|