Solubility of protein fibers obtained from casein solutions and liquid two-phase water-casein-sodium alginate systems.
The solubility of protein and protein-polysaccharide matrix fibers obtained from casein solutions and two-phase water-casein-sodium alginate (W-C-A) systems in water and in 1 M NaCl solutions at different pH at 20 and 100 degrees C has been studied. The matrix fibers obtained from the two-phase W-C-A system are shown to be considerably less soluble than those from the casein solutions. This difference is seen particularly clearly when pH amounts to 5-7. However, it disappears with the spinning two-phase system at temperature above 80 degrees C. An assumption has been made about the matrix fibers being either mixed gels of the thermo-reversible, soluble calcium caseinate and thermo-irreversible insoluble calcium alginate, or complex protein-polysaccharide gels formed with the participation of the calcium ions. This latter assumption is in conformity with the negligible solubility of the protein fibers obtained as a result of the lyotropic gelation of the skimmed milk proteins.
D000464:Alginates / Q000032:analysis*; D000818:Animals; D002364:Caseins / Q000032:analysis*; D002417:Cattle; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D008892:Milk / Q000032:analysis; D011506:Proteins / Q000032:analysis*; D012965:Sodium Chloride; D012995:Solubility; D013696:Temperature; D014867:Water
D000464:Alginates; D002364:Caseins; D006603:Hexuronic Acids; D011506:Proteins; D014867:Water; D012965:Sodium Chloride; D020723:Glucuronic Acid