Cereal Chem 55:58 - 65. | VIEW
The Effect of Heat Treatment on Aggregation and Gelation of Peanut/Milk Protein Blends.
R. H. Schmidt. Copyright 1978 by the American Association of Cereal Chemists, Inc.
Heating 10% protein dispersion of whey protein concentrate and blended systems of peanut protein concentrate or peanut flour with whey protein induced gelation at 100 C. Similarly prepared dispersions of sodium caseinate, calcium caseinate, nonfat dry milk, and blends of these proteins with peanut protein did not gel with heating. A protein concentration of 5.0% or greater was required to form whey protein gels. Gel strength of 10% protein dispersions containing peanut protein blended with whey protein at greater than 50% of the total protein was lower than was gel strength of dispersions containing more peanut protein. Addition of 0.1 to 0.2M NaCl or 30 mM CaCl2 did not affect qualitative gel strength of whey protein concentrate. Gel strength of peanut protein preparations and peanut/whey blends was reduced with addition of NaCl. Addition of 30 mM CaCl2 destroyed gelation of peanut protein, causing precipitation. Gelation of peanut/whey protein blends was less affected by the presence of CaCl2 than by NaCl. While increasing the pH from 7.0 to 10.0 did not affect gel strength of whey protein, gel strength of peanut protein and peanut/whey protein blends decreased with increased pH. The viscosity of 10% protein dispersions of nonfat dry milk did not increase with heating at 100 C for 30 min. Similar heating resulted in increased viscosity of calcium caseinate, peanut flour, and peanut lipoprotein concentrate. The viscosity of sodium caseinate decreased with heating. Increases in viscosity with heating were observed for peanut lipoprotein concentrate/calcium caseinate and nonfat dry milk blends and for peanut flour/nonfat dry milk blends. The viscosity of peanut flour/calcium caseinate blends did not increase with heating. Heat treatment lowered the viscosity of peanut/sodium caseinate blends.