A method for preparing a modified whey protein concentrate (WPC) or whey protein isolate (WPI) is described. It involves (a) providing an aqueous WPC or WPI solution having a protein concentration of 15-50% (w/v), at a pH of 4.7-8.5; (b) heat treating the solution to more than 50 DEG C, for a time that allows protein denaturation to occur the heat treating comprising heating the solution while under conditions of turbulent flow. At the end of the heat treatment, the heat treated material may be promptly transferred to a drier or to be mixed with other ingredients. The heat-treated WPC or WPI is not subjected to a mechanical shear process prior to the transfer other than where liquid is converted into droplets to facilitate drying. The modified WPC is useful in the manufacture of food and drinks where a high protein content is desired without undesirable changes in texture.