QUANTITATIVE DETECTION OF WHEY CREAM IN SWEET CREAM AND BUTTER

A simple and sensitive assay is described that can detect trace amount s of whey cream in sweet cream and in butter made from that cream. The method is based on the detection of sialic acid and involves a color reaction between Ehrlich's reagent and sialic acid. The procedure is f aster than other methods for detection of whey. The method could be te rmed semiquantitative because of the seasonal variability of sialic ac id in cow's milk. However, with a calibration curve, the method is qua ntitative and can easily detect as little as 1% whey cream in sweet cr eam and in the resulting butter. With 1% whey cream in sweet cream, th e purple color indicating the presence of sialic acid is visible to th e naked eye.