FUNCTIONAL-PROPERTIES OF DEPHOSPHORYLATED BOVINE WHOLE CASEIN

Native whole casein and dephosphorylated (40 and 93%) whole caseins we re evaluated for solubility between pH 3 and 8, Ca2+ sensitivity, emul sion capacity, emulsion stability, foaming capacity, and foam stabilit y. The isoelectric point of the modified caseins shifted upward (.5 pH units for 93% dephosphorylated casein) as the degree of dephosphoryla tion increased. Caseins in NaCl solutions were equally soluble above t heir isoelectric points. Dephosphorylated caseins were more soluble in NaCl at pH 3 and in the presence of Ca at pH 7. Emulsifying propertie s were dependent on the amount of casein in solution and were greatest at the pH at which caseins were most soluble. Emulsions made with mod ified caseins were similar to native casein emulsions in initial turbi dity and emulsion activity index values but had lower oil capacities a nd tended to be less stable. Dephosphorylated caseins formed less foam volume during sparging, and the foam was very unstable. The removal o f the phosphate groups from whole casein improved its solubility and r educed emulsion and foaming properties in ways that may be of value to the food industry.