Effect of concentration by ultrafiltration on the heat stability of skim-milk

An examination has been made of the heat stability characteristics of skim-milk concentrate prepared by ultrafiltration (UF). Concentrate prepared by UF was found to be more stable than that prepared by conventional evaporation. In contrast to conventional concentrate, the heat stability of UF concentrate was not appreciably affected by forewarming or addition of permitted stabilizers, but the effect of addition of urea was generally the same for both UF and conventional concentrates; an increase in heat stability was obtained if the milk total solids level was less than 14%. As with conventional concentrate, addition of simple aldehydes induced large increases in the heat stability of UF concentrate. It is suggested that a novel range of sterile milk products could be prepared from UF concentrates. Because of the high protein and low lactose contents of these concentrates, the products might be nutritionally more attractive than those prepared from conventional concentrates.