Characterization of caseinomacropeptides released from renneted raw and UHT treated milks

The kinetics of release of the glycosylated and carbohydrate-free forms of caseinomacropeptide (CMP) was studied in renneted rawand UHT (140 oCfor 10 s) milks. The new chromatographic method utilized allowed quantitative determinations of both molecular torrns. UHT treatment leads to a 40% decrease of the final content in glycosylated forms compared to the value determined in raw milk. The results obtained show that carbohydrate-free ic-casein constitutes 52% of whole x-cassin. When milk is UHT treated, ~-Iactoglobulin only seems to influence the release of the glycosylated form. Nevertheless, no conclusion can be drawn concerning the localization in the micellar structure of both molecular forms of x-caseln.