The Experts below are selected from a list of 66 Experts worldwide ranked by ideXlab platform
Mingzhe Dong - One of the best experts on this subject based on the ideXlab platform.
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a microbial exopolysaccharide produced by sphingomonas species for enhanced heavy oil recovery at high temperature and high salinity
Energy & Fuels, 2017Co-Authors: Houjian Gong, Boxin Ding, Mingzhe DongAbstract:Microbial exopolysaccharides secreted by microorganisms during metabolic processes have been widely used in biotechnology because of their environmentally friendly and renewable nature. This study evaluates the potential of a novel microbial exopolysaccharide, Diutan Gum, which is produced by Sphingomonas species, for enhanced heavy oil recovery at high temperature and high salinity. In addition, two conventional polymers [xanthan Gum and partially hydrolyzed polyacrylamide (HPAM)] used in oil exploitation are compared under the same conditions. It is found that the steady apparent viscosity and dynamic modulus of aqueous Diutan Gum solutions are not sensitive to the temperature and virtually independent of the salinity, while those of xanthan Gum and HPAM significantly decrease at high temperature and high salinity. The retention values of the apparent viscosity and the dynamic modulus of Diutan Gum at 90 °C and 244 121 mg·L–1 salinity are greater than 90%. The gel-like structure of Diutan Gum is depende...
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rheological properties and thickening mechanism of aqueous Diutan Gum solution effects of temperature and salts
Carbohydrate Polymers, 2015Co-Authors: Houjian Gong, Mingzhe DongAbstract:Rheological properties of a new microbial polysaccharide, Diutan Gum in aqueous solution have been systematically investigated. It is found that molecular aggregates of Diutan Gum can be formed at a very low concentration (0.12 g/L), and the mechanism of thickening by Diutan Gum is proposed. The viscosity retention rate of Diutan Gum changes little when increasing the temperature from 298 K to 348 K or in a high salinity solution (55.5 g L(-1)). Gel structure can be formed in the Diutan Gum solution, owing to the finding that the dynamic modulus has an exponential relationship with the concentration. The gel properties of Diutan Gum are not sensitive to temperature, and are virtually independent of cationic environment (Na(+) and Ca(2+)). The temperature/salt tolerance of the Diutan Gum solution is mainly attributed to its perfect double helix molecular conformation, the location of the side chains of its molecules, and its water retention capacity.
Jenifer Santos - One of the best experts on this subject based on the ideXlab platform.
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impact of microfluidization on the emulsifying properties of zein based emulsions influence of Diutan Gum concentration
Materials, 2021Co-Authors: Jenifer Santos, Luis A Trujillocayado, Maria Del Aguila Alcaide, Maria Carmen AlfaroAbstract:Microfluidization is a preparation method that can be used to obtain emulsions with submicron droplet sizes. The first objective of this study was to evaluate the influence of homogenization pressure and cycles on droplet sizes using response surface methodology. Secondly, the influence of the Diutan Gum concentration incorporated in the optimized emulsion on rheological properties, microstructure, and physical stability was investigated. Taking the response surface analysis into account, the emulsion processed at 20,000 psi after four cycles seemed to show the smallest Sauter diameter values. Hence, this emulsion was the starting point to incorporate Diutan Gum. Interestingly, the formation of a 3D network in the emulsion, observed by FESEM, was provoked by Diutan Gum. The emulsion formulated with 0.4 wt.% of Diutan Gum presented rheological gel properties and enhanced physical stability. This work highlights the importance of selecting optimized processing variables using the microfluidization technique and extends the knowledge of using Diutan Gum in combination with zein.
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a comparison of microfluidization and sonication to obtain lemongrass submicron emulsions effect of Diutan Gum concentration as stabilizer
Lwt - Food Science and Technology, 2019Co-Authors: Jenifer Santos, Manuel Gonzalez Jimenez, Tomas Undabeytia, Nuria Calero, José MuñozAbstract:Abstract The objective of this work was to develop emulsions containing lemongrass essential oil and Appyclean 6552 (emulsifier). The emulsions were prepared using two different processing techniques: microfluidization and sonication. A decrease in Sauter diameter with ultrasonic power and residence time in sonicator was observed, reaching values of 195 nm. Emulsions obtained by microfluidization presented similar Sauter values at lower pressures but they underwent recoalescence at higher pressures. However, the emulsion processed at the lowest homogenization pressure in microfluidizer showed the best stability. This emulsion was used as a reference to incorporate Diutan Gum, a thickener. The addition of Diutan Gum provoked the occurrence of viscoelastic properties, showing a weak gel-like behaviour in all the cases. A trend to cross-over point at lower frequencies was detected for 0.3 and 0.4 g/100 g Diutan Gum and this point was reached for 0.2 g/100 g Diutan Gum at 0.65 rad/s. This indicates a higher grade of structuration in more Gum concentrated emulsions, leading to enhanced physical stability. Nevertheless, the emulsion formulated with Diutan Gum above 0.3 g/100 g showed coalescence just after preparation with the subsequent increase of droplet size (above 1 μm).
Maria Carmen Alfaro - One of the best experts on this subject based on the ideXlab platform.
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impact of microfluidization on the emulsifying properties of zein based emulsions influence of Diutan Gum concentration
Materials, 2021Co-Authors: Jenifer Santos, Luis A Trujillocayado, Maria Del Aguila Alcaide, Maria Carmen AlfaroAbstract:Microfluidization is a preparation method that can be used to obtain emulsions with submicron droplet sizes. The first objective of this study was to evaluate the influence of homogenization pressure and cycles on droplet sizes using response surface methodology. Secondly, the influence of the Diutan Gum concentration incorporated in the optimized emulsion on rheological properties, microstructure, and physical stability was investigated. Taking the response surface analysis into account, the emulsion processed at 20,000 psi after four cycles seemed to show the smallest Sauter diameter values. Hence, this emulsion was the starting point to incorporate Diutan Gum. Interestingly, the formation of a 3D network in the emulsion, observed by FESEM, was provoked by Diutan Gum. The emulsion formulated with 0.4 wt.% of Diutan Gum presented rheological gel properties and enhanced physical stability. This work highlights the importance of selecting optimized processing variables using the microfluidization technique and extends the knowledge of using Diutan Gum in combination with zein.
Houjian Gong - One of the best experts on this subject based on the ideXlab platform.
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a microbial exopolysaccharide produced by sphingomonas species for enhanced heavy oil recovery at high temperature and high salinity
Energy & Fuels, 2017Co-Authors: Houjian Gong, Boxin Ding, Mingzhe DongAbstract:Microbial exopolysaccharides secreted by microorganisms during metabolic processes have been widely used in biotechnology because of their environmentally friendly and renewable nature. This study evaluates the potential of a novel microbial exopolysaccharide, Diutan Gum, which is produced by Sphingomonas species, for enhanced heavy oil recovery at high temperature and high salinity. In addition, two conventional polymers [xanthan Gum and partially hydrolyzed polyacrylamide (HPAM)] used in oil exploitation are compared under the same conditions. It is found that the steady apparent viscosity and dynamic modulus of aqueous Diutan Gum solutions are not sensitive to the temperature and virtually independent of the salinity, while those of xanthan Gum and HPAM significantly decrease at high temperature and high salinity. The retention values of the apparent viscosity and the dynamic modulus of Diutan Gum at 90 °C and 244 121 mg·L–1 salinity are greater than 90%. The gel-like structure of Diutan Gum is depende...
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rheological properties and thickening mechanism of aqueous Diutan Gum solution effects of temperature and salts
Carbohydrate Polymers, 2015Co-Authors: Houjian Gong, Mingzhe DongAbstract:Rheological properties of a new microbial polysaccharide, Diutan Gum in aqueous solution have been systematically investigated. It is found that molecular aggregates of Diutan Gum can be formed at a very low concentration (0.12 g/L), and the mechanism of thickening by Diutan Gum is proposed. The viscosity retention rate of Diutan Gum changes little when increasing the temperature from 298 K to 348 K or in a high salinity solution (55.5 g L(-1)). Gel structure can be formed in the Diutan Gum solution, owing to the finding that the dynamic modulus has an exponential relationship with the concentration. The gel properties of Diutan Gum are not sensitive to temperature, and are virtually independent of cationic environment (Na(+) and Ca(2+)). The temperature/salt tolerance of the Diutan Gum solution is mainly attributed to its perfect double helix molecular conformation, the location of the side chains of its molecules, and its water retention capacity.
José Muñoz - One of the best experts on this subject based on the ideXlab platform.
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a comparison of microfluidization and sonication to obtain lemongrass submicron emulsions effect of Diutan Gum concentration as stabilizer
Lwt - Food Science and Technology, 2019Co-Authors: Jenifer Santos, Manuel Gonzalez Jimenez, Tomas Undabeytia, Nuria Calero, José MuñozAbstract:Abstract The objective of this work was to develop emulsions containing lemongrass essential oil and Appyclean 6552 (emulsifier). The emulsions were prepared using two different processing techniques: microfluidization and sonication. A decrease in Sauter diameter with ultrasonic power and residence time in sonicator was observed, reaching values of 195 nm. Emulsions obtained by microfluidization presented similar Sauter values at lower pressures but they underwent recoalescence at higher pressures. However, the emulsion processed at the lowest homogenization pressure in microfluidizer showed the best stability. This emulsion was used as a reference to incorporate Diutan Gum, a thickener. The addition of Diutan Gum provoked the occurrence of viscoelastic properties, showing a weak gel-like behaviour in all the cases. A trend to cross-over point at lower frequencies was detected for 0.3 and 0.4 g/100 g Diutan Gum and this point was reached for 0.2 g/100 g Diutan Gum at 0.65 rad/s. This indicates a higher grade of structuration in more Gum concentrated emulsions, leading to enhanced physical stability. Nevertheless, the emulsion formulated with Diutan Gum above 0.3 g/100 g showed coalescence just after preparation with the subsequent increase of droplet size (above 1 μm).