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Gallegos MJ, Soetrisno DD, Safi Samghabadi F, Conrad JC. Effects of Polymer Molecular Weight on Structure and Dynamics of Colloid-Polymer Bridging Systems. J Phys Chem B 2023; 127:3969-3978. [PMID: 37097805 DOI: 10.1021/acs.jpcb.3c01135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2023]
Abstract
We investigate the effects of polymer molecular weight on the structure and dynamics of a model colloid-polymer bridging system using confocal microscopy. Polymer-induced bridging interactions between trifluoroethyl methacrylate-co-tert-butyl methacrylate (TtMA) copolymer particles and poly(acrylic acid) (PAA) polymers of molecular weight Mw of 130, 450, 3000, or 4000 kDa and normalized concentrations c/c* ranging from 0.05 to 2 are driven by hydrogen bonding of PAA to one of the particle stabilizers. At a constant particle volume fraction ϕ = 0.05, the particles form clusters or networks of maximal size at an intermediate polymer concentration and become more dispersed upon further addition of polymer. Increasing the polymer Mw at a fixed normalized concentration c/c* increases the cluster size: suspensions with 130 kDa polymer contain small clusters that remain diffusive, and those with 4000 kDa polymer form larger, dynamically arrested clusters. Biphasic suspensions with distinct populations of disperse and arrested particles form at low c/c*, where there is insufficient polymer to bridge all particles, or high c/c*, where some particles are sterically stabilized by the added polymer. Thus, the microstructure and dynamics in these mixtures can be tuned through the size and concentration of the bridging polymer.
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Affiliation(s)
- Mariah J Gallegos
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77004, United States
| | - Diego D Soetrisno
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77004, United States
| | - Farshad Safi Samghabadi
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77004, United States
| | - Jacinta C Conrad
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77004, United States
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Optimization of Multiple W 1/O/W 2 Emulsions Processing for Suitable Stability and Encapsulation Efficiency. Foods 2022; 11:foods11091367. [PMID: 35564093 PMCID: PMC9103989 DOI: 10.3390/foods11091367] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 04/29/2022] [Accepted: 05/06/2022] [Indexed: 12/04/2022] Open
Abstract
Double emulsions are a type of multiple emulsions, which can be defined as a multicompartmentalized system where the droplets are dispersed into the continuous phase containing other emulsions. Although double food-grade emulsions have been manufactured, there is a lack of scientific background related to the influence of different processing conditions. This work analyses the influence of processing variables in (W1/O/W2) double emulsions: passes through the valve homogenizer, pressure applied, lipophilic emulsifier concentration, the ratio between the continuous phase (W2) and the primary emulsion (W1/O), and the incorporation of xanthan gum (XG) as a stabilizer. The results obtained show that these emulsions can be obtained after selecting suitable processing conditions, making them easily scalable in industrial processes. In terms of droplet size distribution, the input of higher energy to the system (20 MPa) during emulsification processing led to emulsions with smaller droplet sizes (D3,2). However, more monodispersed emulsions were achieved when the lowest pressure (5 MPa) was used. As for the number of passes, the optimal (emulsions more monodispersed and smaller droplet sizes) was found around 2–3 passes, regardless of the valve homogenizer pressure. However, emulsions processed at 20 MPa involved lower encapsulation efficiency (EE) than emulsions processed at 5 MPa (87.3 ± 2.3 vs. 96.1 ± 1.8, respectively). The addition of XG led to more structured emulsions, and consequently, their kinetic stability increased. The results obtained indicated that a correct formulation of these W1/O/W2 double emulsions allowed the optimal encapsulation of both hydrophilic and lipophilic bioactive compounds. Thus, the development of food matrices, in the form of multiple emulsions, would allow the encapsulation of bioactive compounds, which would result in the development of novelty food products.
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Limnophila aromatica Crude Extracts as Natural Emulsifiers for Formation and Stabilizing of Oil-in-Water (O/W) Emulsions. COLLOIDS AND INTERFACES 2022. [DOI: 10.3390/colloids6020026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study mainly focused on the emulsifying performance of Limnophila aromatica crude extracts obtained by using different ethanolic aqueous solutions (0, 25, 50, 75, and 99.5% (v/v)). All Limnophila aromatica extracts (LAEs) were able to produce emulsions with a volume mean droplet diameter (d4,3) ranging from 273 to 747 nm, except for LAE-99.5 (3269 nm). Only the emulsion prepared by LAE-75 was stable during seven days of storage, without significantly changing droplet size (479–495 nm). The result showed that all LAEs could reduce interfacial tension varied within 12.5 and 16.1 mN/m at the soybean oil/extracts (1% w/w) interface. Compared to other extracts, LAE-75 did not contain the highest protein, saponin, and phenol content (4.36%, 20.14%, and 11.68%, respectively), but it had the lowest ash content (14.74%). These results indicated that the emulsifying performance of LAEs did not rely only on interfacial tension and/or surface-active compounds. The residual demulsifiers, such as inorganic substances, were also significantly involved in the emulsions’ destabilization. Finally, the emulsion consisting of 0.5% (w/w) LAE-75 and 5% (w/w) soybean oil showed considerable stability during storage up to 30 days at different temperatures (5 or 25 °C). Therefore, Limnophila aromatica extract has a potential application as a new source of natural emulsifier.
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Boulhaia I, HadjSadok A, Moulai-Mostefa N, Aouabed A. Impact of octenyl succinic anhydride (OSA) modified starch on the particle size distribution and rheological properties of xanthan gum in aqueous solutions. INTERNATIONAL JOURNAL OF FOOD ENGINEERING 2020. [DOI: 10.1515/ijfe-2019-0279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractEffects of addition of octenyl succinate anhydride (OSA) starch on the structural, rheological and thermo-rheological properties of aqueous solutions of 0.5 (w/v %) xanthan gum were evaluated. Analysis by dynamic light scattering revealed the absence of complex formation in the mixed solution. However, it was noticed that an increase in the concentration of OSA starch (COSA) leads simultaneously to an increase of the number of micelles and their self-assembly within the network formed by the xanthan macromolecules. This same mechanism was observed during the evaluation of the rheological properties. For systems containing 0.5 (w/v %) of xanthan and for which COSA ≤ 4 (w/v %), a thermoreversible behavior was found similar to that of xanthan in solution. Furthermore, for COSA ≥ 5 (w/v %), the rheological behavior remained indifferent to the increase in temperature but, scored a spectacular rise in storage modulus when the cooling temperature begins near 70 °C.
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Affiliation(s)
- Imene Boulhaia
- LME, University of Medea, Ain D’Heb, 26001 Medea, Algeria
- LAFPC, University of Blida 1, Route de Soumaa, 09000 Blida, Algeria
| | | | | | - Ali Aouabed
- LAFPC, University of Blida 1, Route de Soumaa, 09000 Blida, Algeria
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Bouhoute M, Taarji N, Vodo S, Kobayashi I, Zahar M, Isoda H, Nakajima M, Neves MA. Formation and stability of emulsions using crude extracts as natural emulsifiers from Argan shells. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2020.124536] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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6
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Dammak I, do Amaral Sobral PJ. Investigation into the physicochemical stability and rheological properties of rutin emulsions stabilized by chitosan and lecithin. J FOOD ENG 2018. [DOI: 10.1016/j.jfoodeng.2017.09.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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7
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Zamani S, Malchione N, Selig MJ, Abbaspourrad A. Formation of shelf stable Pickering high internal phase emulsions (HIPE) through the inclusion of whey protein microgels. Food Funct 2018; 9:982-990. [DOI: 10.1039/c7fo01800b] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
High internal phase emulsions (HIPE) prepared using whey protein microgels (WPMs) as a surfactant were demonstrated to have substantially higher stability than HIPEs prepared using similar loadings of non-gelled whey protein isolate (WPI) or Tween 20.
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Affiliation(s)
- Somayeh Zamani
- Department of Food Science
- College of Agriculture & Life Science
- Cornell University
- USA
| | - Nicholas Malchione
- Department of Food Science
- College of Agriculture & Life Science
- Cornell University
- USA
| | - Michael J. Selig
- Department of Food Science
- College of Agriculture & Life Science
- Cornell University
- USA
| | - Alireza Abbaspourrad
- Department of Food Science
- College of Agriculture & Life Science
- Cornell University
- USA
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8
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On formulating ophthalmic emulsions. Colloids Surf B Biointerfaces 2014; 122:7-11. [DOI: 10.1016/j.colsurfb.2014.06.039] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 06/16/2014] [Accepted: 06/18/2014] [Indexed: 11/18/2022]
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9
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Tan H, Sun G, Lin W, Mu C, Ngai T. Gelatin particle-stabilized high internal phase emulsions as nutraceutical containers. ACS APPLIED MATERIALS & INTERFACES 2014; 6:13977-84. [PMID: 25102954 DOI: 10.1021/am503341j] [Citation(s) in RCA: 182] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In this paper, we report for the first time the use of a well-dispersed gelatin particle as a representative of natural and biocompatible materials to be an effective particle stabilizer for high internal phase emulsion (HIPE) formulation. Fairly monodispersed gelatin particles (∼200 nm) were synthesized through a two-step desolvation method and characterized by dynamic light scattering, ζ-potential measurements, scanning electron microscopy, and atomic force microscopy. Those protein latexes were then used as sole emulsifiers to fabricate stable oil-in-water Pickering HIPEs at different concentrations, pH conditions, and homogenization times. Most of the gelatin particles were irreversibly adsorbed at the oil-water interface to hinder droplet coalescence, such that Pickering HIPEs can be formed by a small amount of gelatin particles (as low as 0.5 wt % in the water phase) at pH far away from the isoelectric point of the gelatin particles. In addition, increasing homogenization time led to narrow size distribution of droplets, and high particle concentration resulted in more solidlike Pickering HIPEs. In vitro controlled-release experiments revealed that the release of the encapsulated β-carotene can be tuned by manipulating the concentration of gelatin particles in the formulation, suggesting that the stable and narrow-size-distributed gelatin-stabilized HIPEs had potential in functional food and pharmaceutical applications.
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Affiliation(s)
- Huan Tan
- Department of Pharmaceutical and Bioengineering, School of Chemical Engineering, Sichuan University , Chengdu 610065, P.R. China
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10
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Aben S, Holtze C, Tadros T, Schurtenberger P. Rheological investigations on the creaming of depletion-flocculated emulsions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:7967-7975. [PMID: 22554128 DOI: 10.1021/la300221m] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Preventing creaming or sedimentation by the addition of thickeners is an important industrial challenge. We study the effect of the addition of a "free" nonadsorbing polymer (xanthan gum) on the stability against creaming of sterically stabilized O/W emulsions. Therefore, we analyze our samples using microscopy and rheological measurements. At low xanthan concentrations, the emulsions cream. However, above a certain concentration a three-dimensional network of droplets is formed, which can prevent creaming. We attribute the formation of this structure to depletion attraction. The rheological behavior of an emulsion that is macroscopically stable should be elastic, while it should be viscous for a creaming emulsion. In order to distinguish between stable and unstable samples, we measure their relaxation time by mechanical rheology and find a good correlation to the visual observation. However, the measured relaxation times are much shorter than the time-scales, on which we observe creaming. We hypothesize that the measured relaxation time is related to the droplet-droplet interaction. This determines the frequency at which microscopic rearrangements occur, which weaken the network structure prior to creaming. Based on this interpretation, the relaxation time gives direct access to the microstructural processes involved in creaming. We therefore suggest using it as a predictive parameter of creaming stability.
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Affiliation(s)
- Simon Aben
- Competence Center Formulation Technology, BASF SE, GVM/F-J550, Ludwigshafen, Germany
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11
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Rheology and Microstructure of Lecithin-Stabilized Tuna Oil Emulsions Containing Chitosan of Varying Concentration and Molecular Size. FOOD BIOPHYS 2012. [DOI: 10.1007/s11483-012-9253-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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12
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Futamura T, Kawaguchi M. Characterization of paraffin oil emulsions stabilized by hydroxypropyl methylcellulose. J Colloid Interface Sci 2012; 367:55-60. [DOI: 10.1016/j.jcis.2011.10.034] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 09/26/2011] [Accepted: 10/13/2011] [Indexed: 10/15/2022]
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13
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14
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Niño MRR, Patino JMR, Sánchez CC, Ce Judo Fernández M, García JMN. Physicochemical characteristics of food lipids and proteins at fluid-fluid interfaces. CHEM ENG COMMUN 2010. [DOI: 10.1080/00986440302093] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- M. R. Rodríguez Niño
- a Departamento de Ingeniería Química, Facultad de Química , Universidad de Sevilla , Sevilla, Spain
| | - J. M. Rodríguez Patino
- a Departamento de Ingeniería Química, Facultad de Química , Universidad de Sevilla , Sevilla, Spain
| | - C. Carrera Sánchez
- a Departamento de Ingeniería Química, Facultad de Química , Universidad de Sevilla , Sevilla, Spain
| | - M. Ce Judo Fernández
- a Departamento de Ingeniería Química, Facultad de Química , Universidad de Sevilla , Sevilla, Spain
| | - J. M. Navarro García
- a Departamento de Ingeniería Química, Facultad de Química , Universidad de Sevilla , Sevilla, Spain
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15
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Howe AM, Pitt AR. Rheology and stability of oil-in-water nanoemulsions stabilised by anionic surfactant and gelatin 2) addition of homologous series of sugar-based co-surfactants. Adv Colloid Interface Sci 2008; 144:30-7. [PMID: 18842252 DOI: 10.1016/j.cis.2008.08.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The oil-in-water emulsions used in silver-halide photographic coatings are stabilised with anionic surfactants and made in the presence of excess gelatin, which acts as an electrosteric stabilising agent and continuous phase viscosifier. The oil droplet sizes are close to 100 nm but the adsorbed gelatin increases the effective volume of the droplets significantly. These nanoemulsions are manufactured and coated at temperatures in excess of 40 degrees C, where gelatin adopts a random coil structure. At oil concentrations above 15% by volume, the emulsions are viscoelastic liquids with a high low-shear viscosity and strong shear-thinning. The viscosity and shear-thinning can be decreased by reducing the adsorption of gelatin, which can be achieved by addition of nonionic surfactants. This is a rheological study of the effects of adding novel, nonionic sugar-based surfactants on the rheology of photographic nanoemulsions, with additional measurements of static and dynamic surface tension. These surfactants have two sugar (gluconamide) heads and either one or two alkyl tails. Homologous series of each type of sugar surfactant were investigated over a wide range of alkyl tail length. The optimum surfactant choice for commercial applications depends not only on rheological effects but also on ease of synthesis, purification and dissolution, and of course, cost. The dynamic surface tension of the emulsion containing the anionic-nonionic surfactant mixture must also be compatible with the multilayer coating process.
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Affiliation(s)
- Andrew M Howe
- Kodak European Research, 332 Science Park, Milton Road, Cambridge CB4 0WN, UK.
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16
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Lizarraga M, Pan L, Añon M, Santiago L. Stability of concentrated emulsions measured by optical and rheological methods. Effect of processing conditions—I. Whey protein concentrate. Food Hydrocoll 2008. [DOI: 10.1016/j.foodhyd.2007.04.012] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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17
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Berli CLA. Rheology and phase behavior of aggregating emulsions related to droplet-droplet interactions. BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING 2007. [DOI: 10.1590/s0104-66322007000200005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- C. L. A. Berli
- Universidad Nacional del Litoral, Argentina; UNL, Argentina
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18
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Phospholipids and hydrolysates from a sunflower protein isolate adsorbed films at the air–water interface. Food Hydrocoll 2007. [DOI: 10.1016/j.foodhyd.2006.03.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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19
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Miñones Conde J, Rodríguez Patino JM. The effect of enzymatic treatment of a sunflower protein isolate on the rate of adsorption at the air–water interface. J FOOD ENG 2007. [DOI: 10.1016/j.jfoodeng.2005.12.013] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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20
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Sen AK, Roy S, Juvekar VA. Effect of structure on solution and interfacial properties of sodium polystyrene sulfonate (NaPSS). POLYM INT 2006. [DOI: 10.1002/pi.2154] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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21
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Moschakis T, Murray BS, Dickinson E. Microstructural evolution of viscoelastic emulsions stabilised by sodium caseinate and xanthan gum. J Colloid Interface Sci 2005; 284:714-28. [PMID: 15780315 DOI: 10.1016/j.jcis.2004.10.036] [Citation(s) in RCA: 120] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2004] [Accepted: 10/20/2004] [Indexed: 10/25/2022]
Abstract
The time-dependent evolution of the phase-separated microstructure of a caseinate-stabilised emulsion containing xanthan gum added before emulsification has been investigated by confocal laser scanning microscopy, image analysis and rheology. Moderately low levels of xanthan addition lead to depletion flocculation and gravity-induced phase separation. Increasing the polysaccharide concentration causes immobilisation of the microstructure due to an increase in the local viscoelasticity: that is, the emulsion structure cannot easily rearrange to expel xanthan-enriched aqueous serum phase because a weak gel-like network is generated. The effect of xanthan on the evolving microstructure of phase-separated regions, which reflects indirectly the local emulsion micro-rheology, has been estimated from image analysis of time sequences of confocal micrographs. A comparison has been made between object shape analysis using four different shape descriptors. The roundness parameter has been found to be a convenient descriptor for reliably quantifying the structural change in terms of the relaxation rate of xanthan-rich aqueous drops. The Taylor parameter has been used to link the kinetics of drop relaxation to the time-dependent small-deformation rheological behaviour. The analysis of the combined experimental data reveals the difficulty of relating the evolving microstructure to bulk rheological measurements.
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Affiliation(s)
- Thomas Moschakis
- Procter Department of Food Science, University of Leeds, Leeds LS2 9JT, UK
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22
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Kawaguchi M, Kubota K. Rheo-optical properties of silicone oil emulsions in the presence of polymer emulsifiers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:1126-1129. [PMID: 15803686 DOI: 10.1021/la035187x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Oil in water emulsions prepared by dispersion of silicone oils into an aqueous solution of hydroxylpropyl methyl cellulose (HPMC) or poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) block copolymers were characterized by measurements of steady-state shear viscosities, dynamic moduli, and stress-strain sweep curves coupled with optical microscopic observation. The emulsions prepared with HPMC showed solidlike viscoelastic responses and a clear yield stress, whereas the emulsions emulsified by PEO-PPO-PEO block copolymers indicated liquidlike viscoelastic behavior. The difference should be attributed to stronger protective colloidal effects, that is, the former emulsifiers form a more viscoelastic polymer layer adsorbed on the oil droplets than the latter ones. Moreover, the simultaneous optical microscopic observation showed that the emulsions stabilized by HPMC do not flow below the yield stress and beyond the yield stress the movements of oil droplets occur first.
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Affiliation(s)
- Masami Kawaguchi
- Department of Chemistry for Materials, Faculty of Engineering, Mie University, Tsu, Mie 514-8507, Japan
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23
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Roesch RR, Corredig M. Texture and microstructure of emulsions prepared with soy protein concentrate by high-pressure homogenization. Lebensm Wiss Technol 2003. [DOI: 10.1016/s0023-6438(02)00208-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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24
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Yim H, Kent MS, Matheson A, Stevens MJ, Ivkov R, Satija S, Majewski J, Smith GS. Adsorption of Sodium Poly(styrenesulfonate) to the Air Surface of Water by Neutron and X-ray Reflectivity and Surface Tension Measurements: Polymer Concentration Dependence. Macromolecules 2002. [DOI: 10.1021/ma0200468] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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25
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Niño MRR, Sánchez CC, Fernández MC, Patino JMR. Protein and lipid films at equilibrium at air-water interface. J AM OIL CHEM SOC 2001. [DOI: 10.1007/s11746-001-0358-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- M. Rosario Rodríguez Niño
- ; Departmento de Ingeniería Química, Facultad de Química; Universidad de Sevilla; C/.Prof. García González, s/núm 41012 Sevilla Spain
| | - Cecilio Carrera Sánchez
- ; Departmento de Ingeniería Química, Facultad de Química; Universidad de Sevilla; C/.Prof. García González, s/núm 41012 Sevilla Spain
| | - Marta Cejudo Fernández
- ; Departmento de Ingeniería Química, Facultad de Química; Universidad de Sevilla; C/.Prof. García González, s/núm 41012 Sevilla Spain
| | - Juan M. Rodríguez Patino
- ; Departmento de Ingeniería Química, Facultad de Química; Universidad de Sevilla; C/.Prof. García González, s/núm 41012 Sevilla Spain
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26
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Antipova AS, Semenova MG, Belyakova LE, Il'in MM. On relationships between molecular structure, interaction and surface behavior in mixture: small-molecule surfactant+protein. Colloids Surf B Biointerfaces 2001; 21:217-230. [PMID: 11377950 DOI: 10.1016/s0927-7765(01)00174-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We report on the effect of distinct in nature small-molecule surfactants (model, a sodium salt of capric acid, Na-caprate; and commercially important, a citric acid ester of monoglyceride, CITREM; a sodium salt of stearol-lactoyl lactic acid, SSL (Na(+)); polyglycerol ester, PGE (080)) on molecular properties in a bulk and at the air-water interface of globular legumin and random-coiled micellar sodium caseinate. The role of the structure of both proteins and small-molecule surfactants in the effect studied has been elucidated by measurements in a bulk aqueous medium of the enthalpy of their interaction from mixing calorimetry, the change in value of weight average molecular weight of the proteins and the thermodynamics of the pair protein-protein interactions from laser static light scattering as well as, in addition, by measurements of the change in hydrodynamic radius for micellar sodium caseinate from laser dynamic light scattering. The effect of the small-molecule surfactants on the thermodynamics of the protein heat denaturation and thereby on the protein conformational stability has been studied by differential scanning calorimetry in the case of globular legumin. The interrelation between the effects of the small-molecule surfactants on the properties of the proteins in a bulk and at the planar air-water interface has been elucidated by tensiometry. The combined data of mixing calorimetry, differential scanning calorimetry and laser light scattering suggest some complex formation between the small-molecule surfactants and the proteins in a bulk aqueous medium. Predominantly hydrophobic interaction along with electrostatic and hydrogen bonding form the basis of the complex formation. The found effect of the small-molecule surfactants on the surface activity of their mixtures with proteins is governed primarily by both the extent of the protein association, resulting in specific hydrophobicity/hydrophilicity of the surface of the protein associates, and the specific protein conformational stability, for the globular protein, produced by the interaction between the proteins and the small-molecule surfactants.
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Affiliation(s)
- A S. Antipova
- Institute of Biochemical Physics of Russian Academy of Sciences, Vavilov str. 28, 117813, Moscow, Russia
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Dickinson E, Semenova MG, Belyakova LE, Antipova AS, Il'in MM, Tsapkina EN, Ritzoulis C. Analysis of Light Scattering Data on the Calcium Ion Sensitivity of Caseinate Solution Thermodynamics: Relationship to Emulsion Flocculation. J Colloid Interface Sci 2001; 239:87-97. [PMID: 11397052 DOI: 10.1006/jcis.2001.7480] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
We describe the quantitative interrelation between the thermodynamic parameters of caseinate submicelles in the presence of calcium ions (0-14 mM) in aqueous medium and the capacity of the protein to induce depletion flocculation in oil-in-water emulsions at pH 7.0 and ionic strength 0.05 mol dm(-3). Measurements have been made by static and dynamic multiangle laser light scattering of the weight-average molecular weight, the radius of gyration, the hydrodynamic radius, and the second virial coefficient of caseinate submicelles in aqueous solution. Successive thermodynamic approximations with and without consideration of correlations between caseinate submicelles have been used to calculate the osmotic pressure in caseinate aqueous solutions and the free energy of the depletion interaction between droplets in oil-in-water emulsions stabilized by caseinate. Numerical results from both thermodynamic approximations are in reasonably good agreement with experiment, predicting a pronounced decrease in the strength of the depletion attraction at concentrations of Ca(2+) in the range 4-8 mM (with a minimum value at 8 mM). This correlates well with the great enhancement of stability of these emulsions with respect to flocculation in comparison with systems having no added ionic calcium and emulsions with lower (2 mM) or higher (10 mM) Ca(2+) contents. Nevertheless, the allowance for interactive correlations between caseinate submicelles seems to lead to a better prediction of emulsion flocculation on a qualitative level over the whole range of Ca(2+) concentrations studied (2-14 mM). The calculated pronounced decrease in depletion interaction strength is attributable to marked changes in weight-average molecular weight and mean size of aggregates, and to more positive values of the second virial coefficient of caseinate submicelles with increasing Ca(2+) content. Finally, we discuss the part played by the electrical charge on the protein in determining the overall strength of the flocculation-inducing attractive interactions between droplets. Copyright 2001 Academic Press.
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Affiliation(s)
- Eric Dickinson
- Procter Department of Food Science, University of Leeds, Leeds, LS2 9JT, United Kingdom
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Affiliation(s)
- Malek O. Khan
- Theoretical Chemistry, Chemical Center, Lund University, POB 124, SE-22100 Lund, Sweden
| | - Torbjörn Åkesson
- Theoretical Chemistry, Chemical Center, Lund University, POB 124, SE-22100 Lund, Sweden
| | - Bo Jönsson
- Theoretical Chemistry, Chemical Center, Lund University, POB 124, SE-22100 Lund, Sweden
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Yim H, Kent M, Matheson A, Ivkov R, Satija S, Majewski J, Smith GS. Adsorption of Poly(styrenesulfonate) to the Air Surface of Water by Neutron Reflectivity. Macromolecules 2000. [DOI: 10.1021/ma000266q] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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