Sodium Caseinate/Sunflower Oil Nanoemulsion-Based Gels Analyzed by SAXS

CANDAL, R; OCA-AVALOS, J. M. M. DE; BORRONI V.; HERRERA M.L.

Campinhas

Congreso; LNLS 27th Annual Users? Meeting; 2017

Sodium Caseinate/Sunflower Oil Nanoemulsion-Based Gels Analyzed by SAXS V. Borroni1 , J. M. Montes de Oca-Avalos2 , R. Candal2 and M.L. Herrera1 1 Instituto de Tecnología en Polímeros y Nanotecnología (ITPN), UBA/CONICET, Buenos Aires, Argentina; 2 Instituto de Investigación e Ingeniería Ambiental, UNSAM, Buenos Aires, Argentina. mvirborroni@gmail.com The structural elements in foods (air cells, crystals, fat globules) play an important role in determining quality and shelf stability. It is this structure that provides the desired rheological properties of the food (hardness, stiffness, snap, etc.) and contributes to organoleptic properties. Protein gels have attired attention since they allow structuring foods with no trans or saturated fats. In this way, emulsion-based gels are good alternatives to obtain solid foods from liquid raw materials. Therefore, a deep characterization of gel structure is required to determine the feasibility of its application. In this work the effects of protein concentration and sucrose addition on structure of sodium caseinate (NaCas)/sunflower oil nanoemulsion-based gels were studied. Gelation was achieve by homogenous acidification with glucono-delta-lactone (GDL) (final pH 4.5). Oscillatory rheology demonstrate that nanogels are more rigid than gels based in conventional emulsions since they have a greater G?∞ value. By using SAXS and synchrotron radiation we can follow gelation process in real time and describe changes in structure with time. SAXS measurements for the nanoemulsion/gel transition shows that NaCas aggregates increased in size with time suggesting that gelation is consequence of the aggregation of the construction units. In addition, values of initial qmax significantly increased with increasing sucrose concentration (p