Nanoscopic view of a microscopic sodium caseinate O/W emulsion: Protein micellar structure and emulsion physical behavior

CRISTIAN HUCK IRIART; MARIA L HERRERA; ROBERTO J CANDAL; CRISTIANO LUIS PINTO OLIVEIRA

Boston

Congreso; 2012 Annual Meeting of The American Crystallographic Association; 2012

The American Crystallographic Association

The most frequent destabilization mechanisms in Sodium Caseinate (NaCas) emulsions are creaming and flocculation. Coarse or fine emulsions with low protein content are destabilized mainly by creaming. If any other migration mechanism is suppressed flocculation may become the main mechanism of destabilization. Aggregation, which leads to flocculation, is caused by the self-assembly properties of NaCas. Light scattering experiments of casein-stabilized oil-in-water emulsions revealed the formation of large aggregates with micrometer size particles. Small Angle X-Ray Scattering (SAXS) analysis allowed the study of the nanoscale structure of sodium caseinate micelles of colloidal size, in different environments. The results indicated that casein aggregation is strongly affected by disaccharide addition,(i.e. sucrose or trehalose), and it is enhanced by hydrophobic interaction of the emulsion droplets. The micro-to-nano scale results in this study provide a good description of the primary NaCas aggregates in an O/W system, essential for the understanding of better emulsion stability control in food and drugs nanoscale formulation processing.