1997 Volume 3 Issue 2 Pages 97-100
Extensive sauce separation occurred in a white sauce containing bovine serum albumin (BSA) upon heating at 90°C; however, this occurred only slightly in the case where the BSA contained sulfhydryl groups which were modified with N-methylmaleimide (NMM) (modified BSA). SDS-PAGE analysis confirmed that BSA homopolymers were formed through disulfide bonds during heating and that α-and β-casein were not involved in the polymer formation during heating. Although the surface hydrophobicity decreased significantly upon heating in the case of BSA solution or the white sauce containing either BSA or the modified BSA, there was no effect of NMM modification on the decrease in surface hydrophobicity, indicating that the degrees of aggregation of both denatured BSAs were similar. On the other hand, the surface hydrophobicity did not change on heating in the case of white sauce alone. These results suggest that the network-formation of denatured BSA through disulfide bonds is responsible for the extensive sauce separation, while the aggregates of denatured BSA due only to noncovalent interactions cause only slight sauce separation.
