SODIUM CASEINATE STRUCTURAL CHANGES DURING HOMOGENEOUS ACIDIFICATION

CRISTIAN HUCK-IRIART; JAIME A. RINCÓN CARDONA; CRISTIANO LUIS PINTO DE OLIVEIRA; MARIA L. HERRERA; CANDAL, ROBERTO J.

Campinas

Congreso; 24th Annual Users Meeting (RAU); 2014

Structuring liquid oils has become an active area of research in the past decade. Recent strategies to impart solid-fat functionality to liquid oils include gelification of protein emulsions. The aim of this work was to study the effect of sucrose addition on physical properties of acidified sodium caseinate/sunflower oil gels. Gels were prepared from sodium caseinate (NaCas) emulsions with the following composition: 5 wt.% sodium caseinate, 10 wt.% sunflower oil, and 0, 5, 10, 15, 20, and 30 wt.% of sucrose. Emulsions were acidified with glucono-d-lactone (GDL) acid added in a ratio of GDL/protein 1:5 (1 g of protein and 0.2 g of GDL) and 2:5. Small Angle X-Ray Scattering (SAXS) technique was applied to investigate sodium caseinate supramolecular´s structure during the homogeneous acidification. The experimental data was analyzed using advanced modeling approaches. The Form Factor for the NaCas micelle subunits was described by an ellipsoidal core shell model and the structure factor by the particle-particle interactions. For this term the hard sphere structure factor using the Percus-Yevick approximation for closure relation was used. Data analysis provided an increase of the average distance between the subunits after acidification. This is affected by sucrose addition . As will be presented, these nanoscale structural results provided by scattering experiments is consistent with macroscopic results obtained from several techniques.