High Performance Liquid Chromatography with Size Exclusion Column (HPLC-SEC) Method for Identifying the Major Whey Proteins of Whey Protein Products

Abstract

This study was carried-out: a) to develop a high-performance liquid chromatography with size exclusion column (HPLC-SEC) method for the identification of the major whey proteins from selected whey protein products; and b) use the method to estimate the relative composition of the major whey proteins in different whey protein products. An HPLC Shimadzu (LC-10AD VP liquid chromatograph) with system controller (SCL-10A VP) equipped with a pump and auto-injector (SIL-10AD VP) and UV-vis detector (SPD-10AV) was used in the identification of whey proteins in standards and whey protein products. The size exclusion column (SEC) was a Yarra 3 µm, SEC-3000 Column, 7.8 mm I.D. x 30 cm with a security guard. The HPLC-SEC method was successful in identifying the major whey proteins of the different whey protein products. The β-LG contents had the highest level among the whey proteins for all the whey protein products studied, followed by the α-LA and then IgG in both WPC products. However, the α-LA and IgG of the Procream product had almost the same level which was probably due to a different process used in WPC All the major whey proteins with the highest pump flowrate had the shortest elution times while the whey proteins with the lowest pump flowrate had the longest elution times. The optimal pump flowrate was 0.75 mL/min since it gave a faster analysis but differentiate the peaks of the different major whey proteins.