title: Determination of caseinomacropeptide with capillary zone electrophoresis and its application to the detection and estimation of rennet whey solids in milk and buttermilk powder.
abstract: The presence of rennet whey solids in milk powder and buttermilk powder could be detected by analyzing the caseinomacropeptide (6.7 kDa) content by capillary zone electrophoresis. A hydrophilically coated capillary was used in combination with 6 M urea in a citrate buffer at low pH. Under these conditions, genetic A and B variants migrated as a single peak. This afforded a detection limit of 0.4% of rennet whey solids in combination with large volume injections and on-column isotachophoretic concentration of the sample. The detector response (UV at 214 nm) was linear in the range of 1-20% rennet whey solids and the recovery of caseinomacropeptide was 98%. Pseudo-caseinomacropeptide, lacking the N-terminal Met-residue, could be separated from caseinomacropeptide, thus preventing false positive results for some types of acid buttermilk powder.
authors.affiliation: Department of Analytical Chemistry, Institute for Dairy Research (NIZO), Ede, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: van Riel
authors.forename: C
authors.initials: C
authors.lastname: Olieman
mesh_terms: D000818:Animals; D002364:Caseins / Q000032:analysis*; D002417:Cattle; D004586:Electrophoresis / Q000379:methods*; D008892:Milk / Q000737:chemistry*; D008894:Milk Proteins / Q000032:analysis*; D010455:Peptides / Q000032:analysis; D000067816:Whey Proteins
chemical_list: D002364:Caseins; D008894:Milk Proteins; D010455:Peptides; D000067816:Whey Proteins