DETERMINATION OF THE MINOR WHEY-PROTEIN BOVINE LACTOFERRIN IN CHEESE WHEY CONCENTRATES WITH CAPILLARY-ELECTROPHORESIS

In our present work we present the determination of bovine lactoferrin in whey concentrates as they are typically produced by milk and chees e industry after production of cheese. Due to the high total protein c ontent the analysis of whey concentrate samples is difficult and even not possible by using capillary zone electrophoresis with UV detection . To enhance the detection sensitivity we applied a more promising app roach by using affinity interactions in combination with laser-induced fluorescence detection. By mixing fluoresceine isothiocyanate (FITC)- conjugated polyanionic lipopolysaccharide with the mostly positively c harged lactoferrin we found a significant migration time shift which i s clearly dependent on the concentration of the added protein. In the second approach we developed an immunoassay using FITC-conjugated spec ific antibody against bovine lactoferrin. The results of the immunoass ay measurements were compared with data obtained by standard enzyme-li nked immunosorbent assay analysis. (C) 1998 Elsevier Science B.V. All rights reserved.