To provide an acidic beverage in which lactoferrin activity remains high even when stored for a long period of time at room temperature without refrigerated storage. SOLUTION: A step of preparing a raw material solution containing lactoferrin, a pH adjusting step of adjusting a pH to 3.6 to 6.5 by adding a pH adjusting agent to the raw material solution, The manufacturing method of the acidic drink containing the lactoferrin including the sterilization process which heat-sterilizes at 140 degreeC or less for 1 to 100 second, and obtains an acidic drink, and the filling process which fills the said acidic drink with a container. [Selection figure] None【課題】冷蔵保存せずに常温で長期間保存した場合であってもラクトフェリンの活性が高いまま維持された酸性飲料を提供すること。【解決手段】ラクトフェリンを含む原料液を調製する工程、該原料液にｐＨ調製剤を添加してｐＨを３．６～６．５に調整するｐＨ調整工程、ｐＨ調整した前記原料液を９０℃以上１４０℃以下で１～１００秒間加熱殺菌して酸性飲料を得る殺菌工程、及び前記酸性飲料を容器に充填する充填工程、を含むラクトフェリンを含有する酸性飲料の製造方法。【選択図】なし
