Effect of Various Gums on Skimmilk and Purified Milk Proteins

Reactions of gums with skimmilk and with purified proteins were investigated using polyacrylamide gel (PAG) electrophoresis and centrifugation. Some gums caused no reaction with milk proteins, some caused wheying-off or coprecipitation that could be disrupted merely by dilution, and some caused a strong protein-gum interaction. Of the gums tested, only carrageenan, fureellaran, and algin altered any protein electrophoretic pattern. Carrageenan and furcellaran complexed K-casein, preventing it frmn entering PAG. All three gums altered the migration pattern of bovine serum albumin (BSA) on PAG-urea-2mercaptoethanol (PAG-urea-ME). Carrageenan and furcellaran caused sedimentation during centrifugation of a~-and fl-casein in the presence of Ca +* and of ~-casein with or without Ca *+. Centrifugation of algin-protein mixtures did not alter them. Except for BSA, no whey proteins were measurably affected by these gums.