Moon, JH, Hong, YH, Huppertz, T, Fox, PF, Kelly, AL;

2009

February

International Journal of Dairy Technology

Properties of Casein Micelles Cross-Linked By Transglutaminase

Validated

()

62

1

27

32

Factors affecting the cross-linking of milk proteins by transglutaminase (TGase) were studied. Cross-linking of caseins in bovine skim milk was optimal over a very wide pH range. The role of micellar calcium phosphate (MCP) in maintaining the integrity of TGase-treated casein micelles was studied by incubating skim milk with 0.01% (w/v) TGase at 30 degrees C for 1-24 h, followed by removal of MCP from untreated or TGase-treated milk by acidification and dialysis. The protein content and profile of the samples were determined by Kjeldahl and SDS-PAGE, respectively. Whey proteins in unheated milk were not susceptible to TGase-induced cross-linking. The higher level of sedimentable protein in MCP-free TGase-treated milk than in MCP-free control milk indicated that TGase treatment partially prevented disintegration of the micelle on removal of MCP, probably due to extensive intramicellar TGase-induced cross-linking of casein molecules which led to the formation of sedimentable covalently bonded casein aggregates..

DOI 10.1111/j.1471-0307.2008.00442.x