The composition of whey protein fractions that change. depending on the processing methods are reported to influence the functionality of WPI. The WPI prepared by ionexchange technique that was used in our study, normally. contains the full complement of β-lactoglobulin, but much. of the -lactalbumin and some of the immunoglobulins and. other protein components are lost. The principal functional- ity of -lactoglobulin is gelation and thickening.