The effect of pH (7,5 and 3), and the addition of glucose, sucrose and Litesse II, as well as sodium chloride (1,2 and 3%) on the functional properties of whey protein isolate and whey protein concentrate was investigated. Foaming capacity and emulsifying activity index were significantly affected by the change of the pH in the prepared solutions. The addition of glucose to protein solutions had a slight impact (P>0.05) on the functional properties, while the foaming capacity of whey protein isolate solution significantly increased with the presence of sucrose. Litesse II significantly increased the foaming capacity of whey protein isolate and whey protein concentrate solutions, whereas the emulsifying activity index of whey protein isolate solution significantly increased with adding 1 and 2 % Litesse II. The addition of NaCl significantly increased the foaming properties of whey protein isolate and whey protein concentrate solutions and increased the emulsifying activity index of whey protein concentrate solution.