Provided is a method for preparing a sugar solution from which a thermotolerant acidophilic bacteria growth factor that can grow thermotolerant acidophilic bacteria, which are bacteria mainly responsible for the deterioration or rottenness of foods or beverages, is eliminated or reduced. A sugar solution is prepared through the following steps: (a) a step of adding an acid to a raw material sugar solution； (b) a step of filtering the sugar solution prepared in the step (a) through an electrically charged filtration membrane； and (c) a step of collecting a filtrate as the desired sugar solution.本發明係提供一種經除去或減少耐熱性嗜酸菌增殖因子之糖液之調製方法，該耐熱性嗜酸菌增殖因子會使耐熱性嗜酸菌增殖，而耐熱性嗜酸菌即是造成飲食品變質腐敗之主要成因菌。本發明經由下述步驟來調製糖液：(a)於原料糖液加入酸之步驟；(b)將前述(a)步驟所調製之糖液用荷電過濾膜來過濾之步驟；及，(c)將濾液作為上述目的糖液來回收之步驟。
