Moisture-keeping syrup and preparation method thereof

A preparation method of moisturizing syrup belongs to the moisturizing technical field. The preparation method takes starch or starch milk as raw materials and adopts Amano AMT1.2L and Genencor OPTIMAX L-1000 for saccharification and production of the moisturizing syrup after liquefaction, the maltose content in the syrup is 13-20 percent, maltotriose is more than 60 percent, oligosaccharides more than tetraose are lower than 18 percent (as the preparation process detects that the triose content is 68 percent, the patent turns to emphasize the contents of two components of the triose and the tetraose), and the glucose is lower than 5 percent. The preparation method adopts pulp conditioning liquefaction, Amano AMT1.2L and the Genencor OPTIMAX L-1000 saccharification, membrane filtrationand decolorization, continuous counter-current ion exchange, multi-effect plate-typed vacuum evaporation and concentration and other and advanced production technologies for simplifying process, saving energy and reducing consumption during the implementation process, thereby realizing the environmental friendly and high-efficient production of the special syrup for moisturizing.