Studies On The Freeze Drying Mechanism Of Fructooligosaccharides

Fructooligosaccharides is a kind of sanitarian foods with distinctive physic and chemical characters. The price of fructooligosaccharides would be raised if it can be drying into solid by the method of freeze-drying. In this paper, the mechanism of freeze-drying on fructooligosaccharides was studied. In addition, we can draw the following conclusions:1. The temperature distribution mathematical models were erected in the process of freeze-drying:In dry layer, the temperature distribution is:Its boundary condition is In frozen layer;Its boundary condition is t=0 ,2. By use of Crank-Nicholson difference method, the numeric solutions were got.3. In this paper, the numeric solutions were compared with the experimental datum. It was shown that these two temperature curves were coincident well.4. By detecting the eutectic points of fructooligosaccharides, it was found that the eutectic points were declined while the concentration of fructooligosaccharides was deepened. After variance analysis, the curves of eutectic point and the concentration were drawn.5. The factors affecting the process of freeze drying such asfrozen rate, concentration, thickness; heating temperature and method, degree of vacuum, temperature of condenser were analyzed.