Interfacial energy during the emulsification of water-in-heavy crude oil emulsions

The aim of this study was to investigate the interfacial energy involved in the production of water-in-oil (W/O) emulsions composed of water and a Brazilian heavy crude oil. For such purpose an experimental set-up was developed to measure the different energy terms involved in the emulsification process. W/O emulsions containing different water volume fractions (0.1, 0.25 and 0.4) were prepared in a batch calorimeter by using a high-shear rotating homogenizer at two distinct rotation speeds (14000 and 22000 rpm). The results showed that the energy dissipated as heat represented around 80% of the energy transferred to the emulsion, while around 20% contributed to the internal energy. Only a very small fraction of the energy (0.02 - 0.06%) was stored in the water-oil interface. The results demonstrated that the high energy dissipation contributes to the kinetic stability of the W/O emulsions321127137CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESThe authors are grateful to PETROBRAS S.A. and FINEP, Brazil, for the financial support to this study. We also acknowledge the grants conceded by CAPES and CNPq, Brazi

Synergistic Functionality Of Soybean 7s And 11s Fractions In Oil-in-water Emulsions: Effect Of Protein Heat Treatment

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)Oil-in-water emulsions stabilized by different concentrations of two fractions (7S and 11S) of soy protein, with or without heat treatment at 70 or 90 degrees C, were investigated. Emulsions stabilized by 7S showed smaller droplets than those containing 11S. Moreover, emulsions stabilized by heat treated mixtures enriched in 11S produced gel after high pressure homogenization. Emulsions produced from 75% of 7S and 25% of 11S without or with heat treatment at 70 degrees C showed the smallest droplets, indicating a synergistic effect between them. Thus, the combination between 7S and 11S has a great potential to be used as natural emulsifier in food-grade emulsions.181125932602Coordenação 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 [304611/2009-3, 473412/2009-8

INTERFACIAL ENERGY DURING THE EMULSIFICATION OF WATER-IN-HEAVY CRUDE OIL EMULSIONS

Abstract The aim of this study was to investigate the interfacial energy involved in the production of water-in-oil (W/O) emulsions composed of water and a Brazilian heavy crude oil. For such purpose an experimental set-up was developed to measure the different energy terms involved in the emulsification process. W/O emulsions containing different water volume fractions (0.1, 0.25 and 0.4) were prepared in a batch calorimeter by using a high-shear rotating homogenizer at two distinct rotation speeds (14000 and 22000 rpm). The results showed that the energy dissipated as heat represented around 80% of the energy transferred to the emulsion, while around 20% contributed to the internal energy. Only a very small fraction of the energy (0.02 - 0.06%) was stored in the water-oil interface. The results demonstrated that the high energy dissipation contributes to the kinetic stability of the W/O emulsions

Synergistic functionality of soybean 7S and 11S fractions in oil-in-water emulsions: effect of protein heat treatment

Oil-in-water emulsions stabilized by different concentrations of two fractions (7S and 11S) of soy protein, with or without heat treatment at 70 or 90°C, were investigated. Emulsions stabilized by 7S showed smaller droplets than those containing 11S. Moreover, emulsions stabilized by heat treated mixtures enriched in 11S produced gel after high pressure homogenization. Emulsions produced from 75% of 7S and 25% of 11S without or with heat treatment at 70°C showed the smallest droplets, indicating a synergistic effect between them. Thus, the combination between 7S and 11S has a great potential to be used as natural emulsifier in food-grade emulsions.181125932602CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP304611/2009-3 ; 473412/2009-8Sem informação2007/58017-

Silicone/vegetable oil Janus emulsion: Topological stability versus interfacial tensions and relative oil volumes

Several aspects were studied of the formation and destabilization in bulk of silicone/vegetable oil, SO/VO, Janus emulsions, stabilized by Tween 80. in the formation of the emulsions, it was unexpectedly found that the dispersions tended to contain both single and flocculated drops irrespective of the emulsification intensity. Microscopy of the emulsions with no cover glass revealed flocculated drops of a large (200-500 mu m) central SO drop with many small VO drops attached. Applying a cover glass did not significantly change the drop size; instead two-oil Janus drops of well-defined contact angle were found. the emulsions showed rapid creaming irrespective of the preparation method, but a few days storage did not significantly change the drop size in the creamed layer, nor was separation of the oils detected. the total interfacial free energy of the Janus drops at equilibrium was compared to the two relevant alternatives; engulfed and separate drops. the Janus drop free energies were found less for all volume ratios of the oils, when the surfactant concentrations in the aqueous phase was sufficient to prevent spreading of VO on SO. Changing the surfactant concentration to bring the interfacial tensions closer to the critical value for spreading gave declining interfacial free energy difference to that of engulfed drops. (C) 2014 Elsevier Inc. All rights reserved.Ugelstad Laboratory (Norway)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fed Univ Sao Paolo, UNIFESP, Inst Environm Chem & Pharmaceut Sci, Diadema, BrazilNTNU, Ugelstad Lab, Trondheim, NorwayFed Univ Sao Paolo, UNIFESP, Inst Environm Chem & Pharmaceut Sci, Diadema, BrazilCNPq: 800075/2014-5Web of Scienc

Emulsifying properties of Maillard conjugates produced from sodium caseinate and locust bean gum

Emulsifying properties of sodium caseinate -locust bean gum Maillard conjugates produced at different temperatures (54 - 96 ºC), protein/polysaccharide ratios (0.3 - 1.0) and reaction times (1 - 24 hours) were evaluated. Conjugate formation was confirmed by formation of color and high molecular weight fractions and the decrease of the αs- and β-casein bands. The emulsions stabilized by Maillard conjugates showed good stability. The mean droplet diameter (d32) tended to decrease with the increase of incubation time and temperature, except at extreme conditions (24 hours and 90 ºC or 96 ºC) when the partial degradation of the conjugates was probably favored, resulting in phase separation of emulsions. The emulsion viscosity decreased with the increase in the protein/polysaccharide ratio and with the degradation of the conjugates. The conditions used in the experimental design made the optimization of the conjugate production viable, which showed greater emulsifier properties than the pure protein under acid conditions.312429438CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP304611/ 2009-3 ; 473412/2009-82007/ 58017-