Freeze-dry (brief named Freeze-dry) is a stable process of material dried which will put the material contained with water to freeze to solid first, then make among them of the water sublimate from solid to air condition, removing water to preserve materials.Products at solution stage are frozen through sublimation and desorption, then the solvent reduce to a certain extent, thereby preventing the formation of micro-organisms or chemical reaction between the solute and solvent that products can be preserved for a long time and maintained its nature.
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