B. Lieske et G. Konrad, PHYSICOCHEMICAL AND FUNCTIONAL-PROPERTIES OF WHEY-PROTEIN AS AFFECTEDBY LIMITED PAPAIN PROTEOLYSIS AND SELECTIVE ULTRAFILTRATION, International dairy journal, 6(1), 1996, pp. 13-31
Limited proteolysis of whey protein by papain at pH 6.5 and subsequent
thermal unfolding at acidic pH weve studied and correlations between
physico-functional (solubility, foaming, emulsifying) and physico-chem
ical properties were determined. The optimal degree of hydrolysis (DH)
for functionality was about 3.0%, characterized by a significant redu
ction of aggregated whey protein present in commercial ultrafiltered w
hey protein concentrates. From chromatographic and electrophoretic res
ults it may by concluded that peptidic fragments ave derived from bovi
ne serum albumin and molecular unfolded beta-lactoglobulin whereas alp
ha-lactalbumin remained unaffected. Liberated peptidic fragments were
found to support foaming but not emulsification as determined by a sel
ective ultrafiltration. The beneficial effects of proteolytic and ther
mal modification of proteins can be maximized with each protein requir
ing a particular protease to develop a desirable functionality at well
-defined DH.