Sulfhydryl-disulfide interchange-induced interparticle protein polymerization in whey protein-stabilized emulsions and its relation to emulsion stability.

摘要

Emulsions made with pure beta-lactoglobulin and pure alpha-lactalbumin were mixed in a 1:1 ratio and the time-dependent intermolecular sulfhydryl-disulfide interchange between the protein films of beta-lactoglobulin- and alpha-lactalbumin-stabilizedemulsion droplets were studied. In pure protein emulsions, polymerization of beta-lactoglobulin occurred whereas it did not occur in alpha-lactalbumin. However, disulfide cross-linked beta-lactoglobulin/alpha-lactalbumin polymers formed in the cream phase but not in the serum phase of the emulsion-mix emulsions of pure beta-lactoglobulin and pure alpha-lactalbumin emulsions. The extent of polymerization increased with storage time, indicating the occurrence of interparticle polymerization. The interparticle polymerization promoted aggregation of emulsion particles and decreased the kinetic stability of the emulsion.