Effects of salts on the properties of sols and gels prepared from whey protein isolate and process whey protein
Kinekawa, Y.; Fuyuki, T.K.tabatake, N.
Journal of dairy science 81(6): 1532-1544
1998
ISSN/ISBN: 0022-0302
DOI: 10.3168/jds.s0022-0302(98)75719-4
Accession: 003120762
Process whey protein was prepared by heat treatment of whey protein isolate under salt-free conditions. Addition of sodium chloride, trisodium cit-rate, potassium chloride, or calcium chloride to a process whey protein solution increased the viscosity and resulted in gelation at 25 degrees C. In contrast, the viscosity of whey protein isolate solutions was not changed. The properties of whey protein isolate and process whey protein gels prepared by heating at 80 degrees C for 60 min with 25 different salts were measured and compared. Although process whey protein produced gels with the addition of any of the salts examined, whey protein isolate solution did not gel with some salts. The tendency of both protein solutions to gel apparently depended on the lyotropic nature of the cation. Inorganic salts produced firmer gels than did organic salts. The gel strength and water-holding capacity of both proteins decreased as salt concentration increased. When the transparent gels prepared from process whey protein were heated again, the gel firmness increased, adhesiveness decreased, and transparency and cohesiveness slightly decreased, depending on the temperature and duration of the second heating.