Simultaneous separation and quantitation of the major bovine whey proteinsincluding proteose peptone and caseinomacropeptide by reversed-phase high-performance liquid chromatography on polystyrene-divinylbenzene

A precise, sensitive and reliable RP-HPLC method was developed to enable no t only unequivocal determination of alpha-lactalbumin and beta-lactoglobuli n in bovine whey samples, but also simultaneous measurement of proteose pep tone, caseinomacropeptide, bovine serum albumin and immunoglobulin G, The o ptimised method on the Resource RPC column allowed separation of the protei ns in 30 min and could be applied to the analysis of soluble proteins in a variety of commercial and laboratory whey products. Furthermore, some quali tative information on protein heterogeneity and quality could be derived fr om the RP-HPLC analyses with additional data available from on-line electro spray mass spectrometry, Within- and between-day repeatability over a wide range of concentrations was excellent (RSD less than or equal to 5%) for al l proteins except immunoglobulin G and bovine serum albumin where RSD was 7 -10%. Analysis of grouped data from whey protein concentrate and whey prote in isolate samples gave a limit of detection of less than or equal to 0.3% powder mass and a limit of quantitation of less than or equal to 1.0% powde r mass for all proteins except immunoglobulin G, Limits of detection and qu antitation were 0.6% and 2.0%, respectively, for this protein. Quantitative data obtained by the RP-HPLC method compared very favourably with data obt ained by alternative methods of whey protein analysis. (C) 2000 Elsevier Sc ience B.V. All rights reserved.