Computer simulation of dehydration response curves for food drying processes with ventilation drying

摘要

For the optimal design of food drying processes in response to various moisture contents, fish paste sausage was used as the model fish meat, and dehydration response curves obtained under various conditions were quantitatively analyzed, to propose a two - tank or single tank model depending on the moisture contents (W{sub}o). The models were described by a two exponential term expression for the two - tank model in region I (W{sub}o>100% - d. b.) and a single exponential term expression for the single tank model in region II (W{sub}o< 100% - d. b.) respectively. The two expressions were separately characterized depending on the two regions: In region I, by two mass transfer coefficients, k{sub}(La) for free water molecules and k{sub}(Ia) for multi - layered adsorbed water molecules and in region II, by k{sub}(Ga) for the mass transfer coefficient of gaseous water. The values of k{sub}(Ia), k{sub}(Ia) and k{sub}(Ga) were quantitatively evaluated as a function of W{sub}o by using the photographic and graphical analysis of the SEM and TPD data. The mathematical equations derived from the tank models using the limited experimental dehydration response curves were sufficiently applied to simulate all the curves obtained at 35～50℃ and W{sub}o≈51～235% -d. b.