PROBLEM TO BE SOLVED: To provide a protein beverage that has increased the level of solubilized whey protein in an aqueous solution, and to provide a method for preparing the beverage.SOLUTION: There is provided an aqueous solution containing at least about 7.5% of a whey protein. The whey protein contains at least 0.1% of an intact whey protein. A method for preparing the aqueous solution containing 7.5% of the whey protein includes the steps of: mixing a peptide with an intact whey protein to form a whey protein/peptide mixture； mixing water with the protein/peptide mixture to form a protein/peptide/water mixture； and adding an acid in an amount effective to increase solubility of the protein/peptide mixture in water into the protein/peptide/water mixture to produce a protein/peptide aqueous solution.SELECTED DRAWING: Figure 5【課題】水溶液中で可溶化されたホエイプロテインの量を増加させたプロテイン飲料、及びその飲料を調合する方法の提供。【解決手段】少なくとも約7.5％のホエイプロテインを含む、水溶液。ホエイプロテインが、少なくとも0.1％のインタクトホエイプロテインを含む。7.5％ホエイプロテインを含む水溶液の調合方法は、インタクトホエイプロテインをペプチドと配合して、ホエイプロテイン／ペプチド混合物を形成する段階、該プロテイン／ペプチド混合物を水と混合して、プロテイン／ペプチド／水混合物を形成する段階、及び水中での該プロテイン／ペプチド混合物の溶解度を増加させるために有効な量の酸を該プロテイン／ペプチド／水混合物に添加して、プロテイン／ペプチド水溶液を生成する段階を含む。【選択図】図５
