Characterization of caseinomacropeptides released from renneted raw and UHT treated milks

Abstract

Kinetics of release of glycosylated and carbohydrate-free forms of caseinomacropeptide (CMP) were studied in renneted raw and UHT (140 degree C for 10 s) milks. A chromatographic method was used which enabled both molecular forms to be quantified. UHT treatment led to a 40% decrease in the final content of glycosylated forms compared with the value determined in raw milk. Results obtained showed that carbohydrate-free kappa-casein constituted 52% of whole kappa-casein. When milk is UHT treated, beta-lactoglobulin only seems to influence release of the glycosylated form. No conclusion could be drawn concerning the localization in the micellar structure of both molecular forms of kappa-casein.