Phase separation and association of globular protein aggregates in the presence of polysaccharides: 1. Mixtures of preheated beta-lactoglobulin and k-carrageenan at room temperature

Mixtures of globular protein (beta -lactoglobulin) aggregates and polysacch arides (kappa -carrageenan) were studied using dynamic and static light sca ttering, size exclusion chromatography, and optical microscopy. Above a cri tical K-carrageenan concentration the protein aggregates phase separate and form spherical microdomains, which slowly sediment. The effect of concentr ation and size of the protein aggregates was investigated. The phase separa tion is initially reversible upon dilution, but the microdomains become pro gressively more stable until after several days they can no longer be redis solved.