TY - JOUR
T1 - Relationship between Formulation, Gelation Kinetics, Micro/Nanostructure and Rheological Properties of Sodium Caseinate Nanoemulsion-Based Acid Gels for Food Applications
AU - Montes de Oca-Ávalos, Juan M.
AU - Borroni, Virginia
AU - Huck-Iriart, Cristián
AU - Navarro, Alba S.
AU - Candal, Roberto J.
AU - Herrera, María L.
N1 - Funding Information:
This work was supported by the University of Buenos Aires (UBA) through project 20020170100039BA and the Synchrotron Light National Laboratory (LNLS, Campinas, Brazil) through project D06B-IMX-20160535. Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Funding Information:
This work was supported by the University of Buenos Aires (UBA) through project 20020170100039BA and the Synchrotron Light National Laboratory (LNLS, Campinas, Brazil) through project D06B-IMX-20160535.
Publisher Copyright:
© 2019, Springer Science+Business Media, LLC, part of Springer Nature.
PY - 2020/2/1
Y1 - 2020/2/1
N2 - Legislation and concerns about health effects of trans and saturated fatty acids have led to elimination or reduction of them in foods formulation. One of the alternatives for structuring food with healthy ingredients is using food-grade biopolymers such as proteins or polysaccharides to formulate hydrogels. The aim of the present work was to study the relationship among formulation, gelation kinetics, structure, and rheological properties of sodium caseinate (NaCas)/sunflower oil hydrogels prepared from nanoemulsions. NaCas was used as stabilizer in concentrations of 1, 2, 3, or 4 wt.%. Sucrose was also added in 2, 4, 6, or 8 wt.% to the 4-wt.% nanoemulsion. Gelation kinetics was studied by two methods: oscillatory rheometry and Turbiscan. Although gelation time values were significantly different between methods, tendencies were similar: values decreased with increasing protein and sucrose contents. However, the most influential factor on gelation time was the ratio glucono-delta-lactone (GDL)/NaCas. Structure was analyzed by confocal laser scanning microscopy and synchrotron X-ray microtomography. Low-protein content hydrogels (1 or 2 wt.%) had an inhomogeneous structure containing nano- and conventional-size droplets while the 4-wt.% hydrogel kept the initial structural characteristics: homogeneity in dispersed phase distribution and non-aggregated nanodroplets. Sucrose improved structure in terms of homogeneity. Analyses of X-ray microtomoghraphy data showed that while the porosity diminished, the wall width increased with increasing protein and sucrose contents. The hydrogel formulated with 4 wt.% NaCas and 8 wt.% sucrose showed a structure with nanodroplets evenly distributed and the highest G′∞ values of all hydrogels.
AB - Legislation and concerns about health effects of trans and saturated fatty acids have led to elimination or reduction of them in foods formulation. One of the alternatives for structuring food with healthy ingredients is using food-grade biopolymers such as proteins or polysaccharides to formulate hydrogels. The aim of the present work was to study the relationship among formulation, gelation kinetics, structure, and rheological properties of sodium caseinate (NaCas)/sunflower oil hydrogels prepared from nanoemulsions. NaCas was used as stabilizer in concentrations of 1, 2, 3, or 4 wt.%. Sucrose was also added in 2, 4, 6, or 8 wt.% to the 4-wt.% nanoemulsion. Gelation kinetics was studied by two methods: oscillatory rheometry and Turbiscan. Although gelation time values were significantly different between methods, tendencies were similar: values decreased with increasing protein and sucrose contents. However, the most influential factor on gelation time was the ratio glucono-delta-lactone (GDL)/NaCas. Structure was analyzed by confocal laser scanning microscopy and synchrotron X-ray microtomography. Low-protein content hydrogels (1 or 2 wt.%) had an inhomogeneous structure containing nano- and conventional-size droplets while the 4-wt.% hydrogel kept the initial structural characteristics: homogeneity in dispersed phase distribution and non-aggregated nanodroplets. Sucrose improved structure in terms of homogeneity. Analyses of X-ray microtomoghraphy data showed that while the porosity diminished, the wall width increased with increasing protein and sucrose contents. The hydrogel formulated with 4 wt.% NaCas and 8 wt.% sucrose showed a structure with nanodroplets evenly distributed and the highest G′∞ values of all hydrogels.
KW - Confocal laser scanning microscopy
KW - Nanoemulsion-based hydrogel
KW - Synchrotron X-ray microtomography
KW - Turbiscan, oscillatory rheology
UR - http://www.scopus.com/inward/record.url?scp=85076298453&partnerID=8YFLogxK
U2 - 10.1007/s11947-019-02394-9
DO - 10.1007/s11947-019-02394-9
M3 - Artículo (Contribución a Revista)
AN - SCOPUS:85076298453
SN - 1935-5130
VL - 13
SP - 288
EP - 299
JO - Food and Bioprocess Technology
JF - Food and Bioprocess Technology
IS - 2
ER -