THERMAL MODIFICATION OF UF WHEY-PROTEIN . 1. INFLUENCE ON THE PHYSICOFUNCTIONAL PROPERTIES

It was tried to change the functionality of ultra-filtered whey protei ns by thermal treatment at different pH-values. To explain the resulti ng changes with the macro-structure of proteins the samples were teste d by gel chromatography using Sephadex G-100. A thermal treatment at 9 0-degrees-C for 5 min and at pH 6.5 destroys the physico-functional pr operties of whey proteins irreversibly. The same procedure at pH 3.0 o r pH 10.0 improves surface properties like foaming and emulsifying. Un der the same treatment the solubility of so modified whey proteins bec omes similar to that of casein.