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Nanoparticles — Preparation and Applications
Published in Max Donbrow, Microcapsules and Nanoparticles in Medicine and Pharmacy, 2020
Macromolecules can be desolvated by charge changes, pH changes, or by the addition of a desolvating agent causing the so-called salting-out phenomenon. This desolvation results in precipitation of the macromolecule or formation of a coacervate.67 Consequently, desolvation leads to the formation of a new phase. Both effects, precipitation and coacervation, can be considered part of the general area of solubility and phase equilibria.68 Before phase separation occurs, a conformational change of the macromolecules takes place: in a dilute solution, the macromolecule is subject to the osmotic action of the surrounding solvent, which tends to swell it to a larger average size than it would otherwise assume.69 The better the solvent the greater is the swelling of the molecule. Addition of desolvating agent reverses this process and the diameter of the macromolecule coil becomes smaller and smaller. After a certain degree of desolvation is obtained, the molecules begin to aggregate. When sufficient desolvation has occurred, phase separation will take place.
Protein- and Polysaccharide-Based Nanoparticles
Published in C. Anandharamakrishnan, S. Parthasarathi, Food Nanotechnology, 2019
S. Priyanka, S. Kritika, J.A. Moses, C. Anandharamakrishnan
The coacervation technique involves the encapsulation of bioactive molecules in a polymer-rich solution. Coacervation is a novel technique which involves the phase separation of either a single polyelectrolyte or a mixture of polyelectrolytes from a solution and the subsequent deposition of the newly formed coacervate phase around the active ingredient (Anandharamakrishnan, 2014). Furthermore, this technique is based on the interaction between two oppositely charged polyelectrolytes in water to form the coacervate (Anandharamakrishnan, 2015). Moreover, to increase the robustness and stability of the coacervates, the hydrocolloid shell can also be cross-linked either by a suitable chemical cross-linker such as glutaraldehyde, or by an enzymatic cross-linker such as transglutaminase (Zuidam and Shimoni, 2010).
Encapsulation of Flavors, Nutraceuticals, and Antibacterials
Published in Munmaya K. Mishra, Applications of Encapsulation and Controlled Release, 2019
Stéphane Desobry, Frédéric Debeaufort
Coacervation consists in separating from the solution the colloidal particles, which agglomerate into a separate liquid phase called a coacervate. Coacervation can be simple or complex. Simple coacervation involves only one type of polymer with the addition of strongly hydrophilic agents to the colloidal solution. For complex coacervation, two or more types of polymer are used. Active molecules are entrapped in the matrix during coacervate formation by adjusting precisely the ratio between the matrix polymer and the entrapped molecule (Figure 17.2).
Spontaneous interaction of lactoferrin with casein micelles or individual caseins
Published in Journal of the Royal Society of New Zealand, 2018
Coacervation is defined as the separation into two liquid phases in a colloidal solution where the more concentrated phase is the coacervate and the less concentrated phase is the equilibrium solution. Complex coacervation is coacervation caused by the interaction of two oppositely charged colloidal species (IUPAC 1997). Complex coacervation between proteins and polysaccharides has been studied in detail since the pioneering work on gelatin and gum Arabic by Bungenberg de Jong & Kruyt (1929) and Bungenberg de Jong (1949a, 1949b). There are numerous examples of complex coacervates between a range of polysaccharides with a range of proteins, as described in numerous review papers (de Vries et al. 2003; Turgeon et al. 2003; de Kruif et al. 2004; Cooper et al. 2005; Voets et al. 2009; Schmitt & Turgeon 2011; Moschakis & Biliaderis 2017). Theoretical models on complex coacervation have been developed and refined over the years (Overbeek & Voorn 1957; Veis & Aranyi 1960; Veis 1961, 1963; Veis et al. 1967; Tainaka 1979, 1980; Lytle & Sing 2017).
Whey protein isolate—low methoxyl pectin coacervates as a high internal phase Pickering emulsion stabilizer
Published in Journal of Dispersion Science and Technology, 2021
Cui-Ping Zhu, Hui-Hui Zhang, Guo-Qing Huang, Jun-Xia Xiao
The poor stability against pH variation has been recognized as one of the major factors that restrict the practical application of coacervates.[38] Besides, the stability of Pickering emulsions stabilized by inorganic nanoparticles is reported closely related to the medium pH and the variation of this parameter after emulsion preparation has been proposed as a strategy to destabilize Pickering emulsions.[39] Hence, the stability of Pickering emulsions stabilized by coacervates against environmental pH variation must be clarified.
Complexation and coacervation of whey protein isolate with quince seed mucilage
Published in Journal of Dispersion Science and Technology, 2021
Reza Ghadermazi, Asghar Khosrowshahi Asl, Fardin Tamjidi
The aim of this study was to obtain some insights into the mechanisms of formation of WPI–QSM complex coacervates by analysis of turbidity, ζ-potential, coacervation yield, thermal stability, interaction nature, and morphological characteristics. These coacervates may be useful for application in food, pharmaceutical, and cosmetic products.