Experimental Study on Optimized technological parameters of Preservation for freeze-drying of Pteridium Aquilinum

The influence of drying parameters of freeze-drying on quality of Pteridium Aquilinum drying was investigate, and the impact of drying board temperature, drying chamber pressure and material thickness on vitamin C content was studied by nonlinear regressional orthogonal design. Using single and double factor analysis method, the relation between experimental criteria and drying parameters was established, and the influence order of the parameters was determined. Experimental results showed that drying chamber pressure had the greatest influence than drying board temperature and material thickness. The optimal combination of the preserved quality parameters for the freeze-drying technology of Peridium aquilium was obtained through optimized theory in nonlinear method. They are as follows: the pressure of drying chamber is 55Pa, the temperature of the board is 42.5°C, and material thickness is 16.3mm.