Development of multiple emulsions based on the repulsive interaction between sodium caseinate and LBG

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The stability of oil-in-water, water-in-water and multiple emulsions containing sodium caseinate (Na-CN) and/or locust bean gum (LBG) at pH 5.5 was investigated with different compositions using a visual analysis (creaming and/or phase separation), optical microscopy and rheological measurements. Oil-in-water emulsions (O/W) were produced by high pressure homogenization, which promoted the formation of very small droplets (similar to 0.4 mu m) and hindered the destabilization process. In the second step of this study, a visual phase diagramwas constructed in order to identify the concentrations of sodium caseinate (Na-CN) and locust bean gum (LBG) that led to phase separation at pH 5.5. A mixed solution composed of 3% (w/v) Na-CN and 0.3% (w/v) LBG was chosen to produce the water-in-water and multiple emulsions. After centrifugation, the solution was separated into an upper phase rich in polysaccharide (PS) and a bottom phase rich in protein (PR), which were mixed in different proportions (1:3, 1:1, 3:1), forming the water-in-water (W/W) emulsions. The stability, microstructure and rheological properties of the W/W emulsions depended strongly on the composition of the biopolymers. An increase in the polysaccharide concentration in the W/W emulsions led to the production of more viscous and stable systems. Multiple emulsions with different characteristics were prepared and also depended on the biopolymer composition. The system with the highest polysaccharide content was the only one that showed an O/W/W structure, while the others presented the microstructure of an O/W-W/W emulsion. (C) 2011 Elsevier Ltd. All rights reserved.261126134Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2006/02318-4, 2007/58017-5]CNPq [301869/2006-5

Oil-in-water emulsions stabilized by sodium caseinate: Influence of pH, high-pressure homogenization and locust bean gum addition

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The effect of pH, addition of a thickening agent (locust bean gum) or high-pressure homogenization on the stability of oil-in-water emulsions added by sodium caseinate (Na-CN) was evaluated. For this purpose, emulsions were characterized by visual analysis, microstructure and theological measurements. Most of the systems were not stable, showing phase separation a few minutes after emulsion preparation. However, creaming behavior was largely affected by the pH, homogenization pressure or locust bean gum (LBG) concentration. The most stable systems were obtained for emulsions homogenized at high pressure, containing an increased amount of LBG or with pH values close to the isoelectric point (pI) of sodium caseinate, which was attributed to the size reduction of the droplets, the higher viscosity of continuous phase and the emulsion gelation (elastic network formation), respectively. All the studied mechanisms were efficient to decrease the molecular mobility, which slowed down the phase separation of the emulsions. In addition, the use of sodium caseinate was also essential to stabilize the emulsions, since it promoted the electrostatic repulsive interactions between droplets. (C) 2009 Elsevier Ltd. All rights reserved.974441448Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2006/02318-4, 2007/58017-5]CNPq [301869/2006-5

Acid gelation of native and heat-denatured soy proteins and locust bean gum

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The effects of protein concentration and locust bean gum (LBG) addition on the mechanical properties, microstructure and water holding capacity of acidified soy protein (SPI) gels were studied. The protein was employed in two different states: (i) native and (ii) heat denatured. A slow acidification rate was induced in both systems by applying glucono-d-lactone (GDL). The results indicated that the gels of native SPI were weaker, less deformable and showed lower water holding capacity than the gels of heat-denatured SPI. The LBG addition led to an increase in the strength and water holding capacity of SPI gels, independent of the protein state (native or denatured). These results indicated that the properties of texture and water holding capacity of the SPI acid gels can be modulated by the process conditions or by the addition of other ingredients, such as polysaccharides.483620627Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2004/08517-3]CNPq [301869/2006-5, 477620/2003-5

Interactions between sodium caseinate and LBG in acidified systems: Rheology and phase behavior

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The behavior of model systems formed by different concentration of sodium caseinate and locust bean gum (LBG) was investigated using confocal microscopy (CSLM) and theological measurements in order to determine the interaction between these two ingredients in acidified dairy products. A visual phase diagram was constructed at different biopolymer concentrations and four different types of systems were observed for the mixtures in the isoelectric point of protein: one-phase gels (G1P), two-phase gets (G2P), one-phase liquid mixtures (L1P) and two-phase liquid mixtures (L2P). These different systems resulted from the different kinetics of phase separation and gel formation. The one-phase systems (gels and liquid mixtures) showed a micro-phase separation when visualized by CSLM, although they were homogeneous at macroscopic level. In a general way, the micro or macro phase separation led to a biopolymer concentration on separated phases, resulting in an increase of the stress at fracture for the gels or the viscosity for the liquid mixtures. However, the behavior of the whole system did not correspond to the sum of the mechanical properties of separated phases. (C) 2009 Elsevier Ltd. All rights reserved.23820852093Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2003/00578-0, 2004/08517-3]CNPq [301869/2006-5

kappa-Carrageenan-sodium caseinate microgel production by atomization: Critical analysis of the experimental procedure

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The influence of atomization process to produce kappa-carrageenan and kappa-carrageenan/sodium caseinate microgels was studied experimentally (aspect ratio and particle size distribution) and theoretically (dimensionless parameters). Moreover, rheological behavior of microgel suspensions was evaluated to examine their potential application in food products. Experimental results demonstrated that the size of microgels was influenced by feed flow rate, compressed air flow rate and composition of solutions, while their shape depended on the viscosity and surface tension of biopolymer solutions. Regarding the dimensionless numbers, higher values of Reynolds number of liquid layer (Rex(lambda l)) and Weber number (We(l)) led to smaller particles, while the decrease of Ohnesorge number (Oh) was related to lower sphericity of microgels. Rheological behavior of suspensions depended on not only the morphology and size of microgels, but also their composition. Incompatibility between kappa-carrageenan and sodium caseinate in mixed microgels led to suspensions with more complex rheological behavior at determined biopolymer concentrations. (C) 2010 Elsevier Ltd. All rights reserved.1041123133Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2007/58017-5]CNPq [301869/2006-5

Development of Na-CN-kappa-carrageenan Microbeads for the Encapsulation of Lipophilic Compounds

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The ionotropic gelation of double-layered emulsions composed of sodium caseinate and kappa-carrageenan at pH values of 7 and 3.5 was evaluated, in order to obtain potential encapsulation matrices for hydrophobic compounds. The influence of some of the extrusion process variables (nozzle diameter at fluid exit and collecting distance) on the microbead production was studied, as well as the stability of the microbeads. The fluid nozzle diameter showed little influence on the shape of the microbeads, with a slight tendency for a decrease in microbead diameter with increase in fluid nozzle diameter. On the other hand, the collecting distance strongly influenced the microbead shape and they became more spherical (aspect ratio was reduced from similar to 2.0 to similar to 1.4) as the collecting distance was increased from 10 cm to 50 cm. The emulsion pH did not affect the aspect ratio of the microbeads, but the diameter was greater for microbeads produced at pH 3.5. This difference was attributed to the kind of interactions occurring between the kappa-carrageenan and sodium caseinate at these distinct pH values. The microbeads were highly unstable when dispersed in deionized water, sugar solutions and low salt concentrations, releasing the encapsulated oil. However, no release of oil from the microbeads was observed when they were dispersed in ethanol or potassium chloride solutions with concentrations above 0.75 %, although their shape was modified when dispersed in ethanol. In general, the results obtained demonstrated the viability of the extrusion process to produce biopolymer-based microbeads and the potential application of these systems.73264275Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2007/58017-5, 08/57906-3]CNPq [304611/2009-3, 573913/2008-0