An Experimental Research On The Adsorption And Desorption Isotherms Of Lycium And Their Computer Simulation

The water activity(Aw) called equilibrium relative humidity(ERH) and the equilibrium moisture content(Me) are two important parameters in lycium processing such as drying,storage and so on. The relationship between ERH and Me in a certain temperature is defined as sorption isotherms.In this thesis,the sorption isotherms were obtained by means of statics to detect the Me values for both adsorption and desorption of lycium at 20 ℃ ,30 ℃ and 40 ℃ .Meantime,the sorption thermodynamic parameters,such as the net isosteric heat(Qa) and sorption energies(L) for lycium,were analyzed based on the theory of agricultural products and its animalcule ,to show the end-point of drying and safety storage condition for lycium. By fitting the experimental data of sorption into the commonly-used sorption istherm models of agricultural products in way of SAS NLIN regression,and evaluating the fitting-agreement of models,the modified GAB model was proved to be the best sorption model to express the adsorption isotherm and the desorption isotherm for lycium.In order to better predict the sorption characteristical parameters and directly perceive the adsorption isotherm and the desorption isotherm of lycium,the adsorption isotherm and the desorption isotherm are simulated in computer,in which the method and programe can be served as some reference for simulating the adsorption isotherm and the desorption isotherm of other agricultural products.