Protein Interactions of Cheese Whey-Pea Flour Blends

Abstract

Fresh cheese whey and whey ultrafiltrate were compared to water as an extractant for pea flour nitrogen. Whey was 18% less efficient than water at pH 8.0 and 48% less efficient at pH 6.8. Whey ultrafiltrate was only slightly more efficient than whey.Affinity columns were prepared by coupling isolated whey proteins, pea albumins or pea globulins to Sepharose 4B, and solutions of the same proteins were chromatographed on the various columns. At low ionic strength pea globulins showed considerable affinity for the whey protein column and also for the pea albumin column. Pea albumins showed little affinity for whey proteins. On chromatography of a pea protein solution containing both albumins and globulins on the whey protein column, it appeared that albumins were masking the binding sites of the globulins. Proteins retained by the affinity columns were readily eluted by increasing the ionic strength. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the chromatographic peak fractions indicated some tendency for selective adsorption of certain pea globulin subunits by the whey protein matrix.