High-purity food tannin was prepared from gallnut by solvent extraction, via. leaching in water, extracting by ethyl acetate and removing color with active carbon.

• 采用溶剂萃取法,以五倍子为原料,水为溶媒进行浸提,再用乙酸乙酯为溶剂进行萃取,通过脱色制备高纯度食品鞣酸。