The distributions of major whey proteins in acid wheys obtained from caprine/bovine and ovine/bovine milk mixtures

Abstract

The distributions of major whey proteins in acid wheys from different caprine/bovine and ovine/bovine milk mixtures were investigated using native-polyacrylamide gel electrophoresis (PAGE). Significantly different distributions of major whey proteins as individual proteins or as the sum of the same protein from different species were established. The caprine major whey proteins were dominant in mixtures with 10%, 20% and 30% bovine milk. The total beta-lactoglobulin to alpha-lactalbumin (beta-LGs/alpha-LAs) ratios ranged from 1.37 to 2.12 for caprine/bovine acid wheys. The corresponding ratios for ovine/bovine acid wheys were in the range 2.59-2.12. Linear relationships were estimated among the amounts of added bovine milk and the percentages of individual major whey proteins in all milk analysed, with square correlation coefficients from 0.990 to 0.997. These correlations enabled the use of native-PAGE as simple, reliable and low cost analytical method for determination the distributions of major whey proteins in caprine/bovine acid wheys.