ELLMAN REAGENT FOR DETERMINATION OF THE HEAT-TREATMENT OF MILK POWDER- IMPROVED ANALYTICAL PROCEDURE BASED ON A STOPPED-FLOW KINETIC-STUDY

The reproducibility and accuracy of the method for determination of he at treatment of milk powder based on the reaction between Ellman's rea gent (5,5'-dithio-bis(2-nitrobenzoic acid)) and exposed SH-groups may be improved by careful salting-out of the protein by stepwise addition of (NH4)(2)SO4 and by rigorous pH-control using a 0.10 M borax buffer (pH 9.50) for adjustment of the milk pH to 8.00 while using a standar d curve obtained at the same pH.