Influence of added kappa casein and beta lactoglobulin on the heat coagulation time ph profile of buffalo milk
Bhavadasan, M.K.; Rajput, Y.S.; Ganguli, N.C.
Milchwissenschaft 41(11): 707-709
ISSN/ISBN: 0026-3788 Accession: 005679744
Unlike bovine milk, buffalo milk exhibits poor heat stability in a broad pH region of 6.9 to 7.3. Incremental addition of .beta.-lactoglobulin to buffalo milk did not influence the heat stability at the above pH region, although increased slightly the stability at lower pH values. Added bovine .kappa.-casein or buffalo .kappa.-casein did not abolish the broad minimum in the heat coagulation time (HCT)-pH profile of buffalo milk. Buffalo milk in the presence of glyceraldehyde (10 mM) showed typical type A bovine heat stability characteristics. Added .kappa.-casein (2 mg/ml) in such milk systems completely abolished the minimum observed in the HCT-pH profile. These results suggest that the effect of added .kappa.-casein on the HCT-pH profile of buffalo milk depends largely on the net negative charge on the casein. The rate of heat-induced .kappa.-casein hydrolysis in buffalo milk was retarded by glyceraldehyde at pH 7.1, where the aldehyde also markedly improved the heat stability of buffalo milk.