β-Lactoglobulin-κ-Casein Interaction in Various Salt Solutions

Mixtures of 2% each of/~-laetoglobulin ABC and K-casein AB were heated at 110 C for 30 rain in solutions containing deionized water, .02 M calcium, 5% a-lactose, .035% phosphorous, .2% citrate, .14% chlorine, synthetic ultra-filtrate, and milk dialysate. Differences in composition of interaction products were shown qualitatively by zone electrophoresis and quantitatively by preparative electropheresis. A minimum interaction of 13.85 ~-lactoglobulin with 17.1% K-casein occurred in de-ionized water while a maximum of 76.6~ ~-lactoglobulin interacted with 83.3% K-caseirr in milk dialysate. Rates of interactions for other reaction solutions varied between the two. Zonal electrophoresis of individual fl-lactoglobulin and K-casein treated similarly showed that some interaction products may ensue from the effect of heating on these proteins.