PROBLEM TO BE SOLVED: To provide a method by which caffeine can highly safely and selectively be removed by adsorption without using an additive such as a metal.SOLUTION: The water-insoluble gel for adsorbing the caffeine is prepared by irradiating persimmon juice with natural light and/or ultraviolet rays in the presence of oxygen to oxidize the persimmon juice. The caffeine is removed from a solution containing the caffeine by bringing the solution into contact with the water-insoluble gel.COPYRIGHT: (C)2013,JPO&INPIT【課題】金属等の添加物を使用せずに安全性が高く及びカフェインを選択的に吸着除去できる方法を提供する。【解決手段】柿渋を酸素存在下で自然光及び/又は紫外線照射を行い酸化させることにより得られるカフェイン吸着用非水溶性ゲル調製し、該非水溶性ゲルとカフェインを含む溶液を接触させることにより、該溶液からカフェインを除去する【選択図】なし
