Carbohydrate analysis of the glycopeptides released by the action of rennin on whole milk

Abstract
Summary: A gas-liquid chromatographic method is described for the simultaneous estimation of the carbohydrates attached to the glycopeptides released by the action of rennin on whole milk. The method can also be used for κ-casein. Certain of the findings may be applicable to other glycoproteins or glycopeptides. In particular: (a) the conditions for methanolysis of the carbohydrates from the glycopeptides must be chosen carefully to avoid decomposition ofN-acetyl neuraminic acid; (b) it is not possible to obtain a satisfactory calibration forN-acetyl neuraminic acid using the free acid as a standard.