Soursop juice stabilized with soy fractions: a rheologial approach

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The potential use of soybean soluble polysaccharide (SSPS) as a stabilizer in acidic beverages was evaluated using rheological and stability studies. For this purpose, soy-based beverages were formulated with soy protein isolate (SPI) and soursop juice due to the low stability of this kind of dispersion. The influences of the concentrations of soybean soluble polysaccharide, calcium chloride, and soy protein isolate on the stability and rheology of soursop juice were evaluated using a factorial experimental design. Interactions between the concentrations of soybean soluble polysaccharide and soy protein isolate exerted a positive effect on the maximum Newtonian viscosity. The stability was positively influenced by the soybean soluble polysaccharide and soy protein isolate concentrations, but the interactions between soy protein isolate and CaCl2 also affected the sedimentation index. These results suggest that soybean soluble polysaccharide is effective in stabilizing fibers and proteins in acidic suspensions due to the increase in viscosity and steric effect caused by the formation of complexes between the soybean soluble polysaccharide and soy protein isolate.323558567Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CAPES [Proex 304/2007]CNPq [301869/2006-5

Characterisation of soy extract processed under different drying methods and extraction conditions

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)Soybean extract (SE), enriched in soy soluble polysaccharide (SSPS), was evaluated in three different conditions varying in extraction temperature and drying process: SE-A -80 degrees C, freeze-dried, SE-B -80 degrees C, spray-dried, SE-C -95 degrees C, spray-dried. Spray-dried SE presented lower moisture content, smaller and more uniform particles. In addition, zeta potential showed the same negative surface charge for all extracts showing the prevailing behaviour of SSPS. Moreover, all biopolymers were composed of three main molecular weight (Mw) fractions, but the Mw distribution was different between the three ingredients, reflecting their rheological behaviour in aqueous solution. Higher mean Mw led to enhanced apparent viscosity observed in neutral and acid pH for SE-A, followed by -B and -C, respectively. The inverse behaviour was observed for intrinsic viscosity at neutral pH. However, SE-C showed lower intrinsic viscosity at acid pH, which was attributed to proteinpolysaccharide interaction presents in the solution.483503511Coordenação 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)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)CAPES [Proex 304/2007]CNPq [301869/2006- 5]FAPESP [2009/54137-1, 2004/08771-7

Microemulsions and liquid crystalline formulated with triacylglycerols: Effect of ethanol and oil unsaturation

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)Pseudo-ternary phase diagrams were constructed in order to evaluate the effect of the prevailing oil unsaturation and cosurfactant concentration on the phase behavior of systems prepared with sunflower oil or high oleic sunflower oil (HOSO), water, Tween 80 and ethanol. The phase diagrams showed small areas of one single translucid phase with production of water-in-oil (L-2) and oil-in-water (L-1) microemulsions. A higher cosurfactant concentration increased microemulsion area and allowed solubilize more water using lower surfactant content. Moreover, small angle X-ray scattering (SAXS) measurements showed that depending of the composition the surfactant self-assembly led to lamellar (L-alpha) or hexagonal (H-1) structures. Microemulsions showed Newtonian behavior. while L-alpha and H-1 showed shear-thinning behavior. viscoelasticity and thixotropy. This more complex rheological behavior was accentuated at lower cosurfactant concentration and with the less unsaturated oil, showing that both oil unsaturation and ethanol content exerted influence on systems properties. However, the higher concentration ethanol masked the effect of oil unsaturation. (C) 2012 Elsevier B.V. All rights reserved.4153140Fundação 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)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FAPESP [EMU 09/54137-1

Effects of a cosurfactant on the shear-dependent structures of systems composed of biocompatible ingredients

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)The phase transitions of systems composed of water, polyoxyethylene sorbitan monooleate (Tween 80), medium-chain triglycerides (MCTs) and ethanol were evaluated based on rheological properties using different proportions of MCT:ethanol (1:0, 2:1 and 1:2). Higher ethanol contents led to a broadened microemulsion (ME) region and a diminished liquid crystalline (LC) region in the phase diagram and resulted in the formation of systems with smaller particle sizes, lower viscosities and less shear-thinning. Different systems were obtained from the water titration of an initial mixture of 70% (w/w) surfactant and 30% (w/w) oil + ethanol. At low water contents, Newtonian W/O MEs were produced. At intermediate water contents, LC phases were observed, including viscous and gel-like structures with viscoelastic properties and complex rheology (shear-thinning, Bingham plastic or Herschel-Buckley behaviour). In addition, these samples exhibited time-dependent behaviours, showing thixotropy in systems rich in amphiphilic and nonpolar components and anti-thixotropy in systems with a prevalence of polar (ethanol and water) components. According to oscillatory measurements, cubic phases were most likely formed at 40% (w/w) water in systems with low (or an absence of) ethanol. At higher water contents (>50%, w/w), O/W milk-like emulsions were produced in systems with low ethanol contents, whereas O/W MEs were produced in the system with a high ethanol content. O/W MEs exhibited larger droplet sizes and lower viscosities than W/O MEs. The different structures depended strongly on the system composition, which enables the production of textures with potential applications in the food, cosmetic and pharmaceutical industries. (C) 2012 Elsevier B.V. All rights reserved.3985463Fundação 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)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FAPESP [EMU 09/54137-1]CNPq [473412/2009-8, 143050/2009-5

Production of hybrid gels from polysorbate and gellan gum

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)The association of gellan gum and nonionic surfactant in the gel formation was explored in systems with high biopolymer concentration (3% w/w). Gels formed with different concentrations of polysorbate 80 (0-60% w/v) and pH (3.0 and 5.0) were evaluated from their microstructure, mechanical and theological properties. The high concentration of polysaccharide in water at more acidic pH (3.0) favored the aggregation of molecules, producing harder gels even at high temperatures. The thermal theological measurements showed two distinct behaviors which depending on the predominance of polysaccharide or surfactant in the systems. The gellan gum properties were predominant at lower surfactant concentrations. However, the surfactant micelles could enhance the linkage between the macromolecules through the few remaining hydrophobic sites of the biopolymer and consequently increase the gel strength that presented strain-hardening behavior. As the surfactant concentration was increased to 30% (w/w), different slopes in the theological curves were observed. They were attributed to the structuration of the polysorbate. At higher concentration of polysorbate, the surfactant prevented the gellan gum aggregation and the gum did not exert influence on the theological behavior, which was related to the surfactant structuration. The surfactant self-assembly produced weaker gel-like structures than the gellan network, presenting a strain-weakening behavior. Thus, results suggest that depending on the medium conditions, gellan-polysorbate 80 interaction could produce different gels with different technological properties. (C) 2013 Elsevier Ltd. All rights reserved.541501507Fundação 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)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FAPESP [EMU 09/54137-1]CNPq [Universal 479459/2012-6

Influence of drying conditions on the gelling properties of the 7S and 11S soy protein fractions

Soy protein fractions rich in p-conglycinin (7S) or glycinin (11S) were freeze dried or spray dried at temperatures of 120, 150 or 180 degrees C. The fractions were characterized for their particle size distribution, sorption isotherms and by scanning differential calorimetry. The gelling capacity of the protein fractions was studied at pH values of 3 and 7 using oscillatory measurements, mechanical properties and water holding capacity. The rheological measurements showed that viscous modulus (G '') predominated at low temperatures and the elastic modulus (G') at high temperatures. At pH 3, the G'-G '' crossover occurred at lower temperatures when compared to pH 7. This behaviour was more accentuated for the 11S fractions due to its capacity to form stronger gels. An increase of drying temperature led to a displacement of the gel point to higher temperatures and decreased the elasticity modulus or gelling capacity of protein fractions. These results were confirmed by the mechanical properties, since at higher temperatures the gels were more fragile and brittle, especially when formed at pH 7. (C) 2012 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.91C211112