A transparent adjusted milk whey protein is prepared by a method in which milk whey protein is purified and then the pH of a solution containing the milk whey protein is adjusted to not higher than 4 or not lower than 6. The solution may be heated to a temperature not lower than 55 DEG C before or after adjusting the pH. Further, an adjusted milk whey product is prepared by a method in which the pH of a solution containing milk whey protein is adjusted to not higher than 4 or not lower than 6 and the solution is heated at a temperature not lower than 55 DEG C and cooled to a temperature not higher than 10 DEG C, or a method in which the pH of a solution containing purified milk whey protein is adjusted to not higher than 4 or not lower than 6 under such a condition as salt content of the solution is 0 or not higher than 50 mM, and the solution is heated at a temperature not lower than 55 DEG C and cooled to a temperature not higher than 10 DEG C.
展开▼