Complexation of chitosan and gelatin: From soluble complexes to colloidal gel

ABSTRACT The formation of soluble and insoluble complexes between chitosan (CH) and gelatin type B (GB) was investigated as a function of pH (3.0–6.5), sodium chloride (NaCl) concentration (0–100 mM), and storage time (up to 40 days). The turbidity of the CH/GB complexes achieved a maximum value at pH 5.5 and increased with time. The increase of ionic strength first intensified the complex formation but then decreased it at higher salt content. After phase separation, the main component of the separated dense phase was water, from 95.5 to 97.8 wt%, depending on NaCl concentration. With increasing storage time, the insoluble phase changed from a liquid-like system to a thermoreversible colloidal gel, as supported by confocal laser scanning microscopy as well as rheological data. The formation of this colloidal gel is explained in terms of electrostatic complexation and hydrogen bonding. GRAPHICAL ABSTRACT

[1]  N. Garti,et al.  Protein-Polysaccharide Interactions for Stabilization of Food Emulsions , 2002 .

[2]  M. Saravanan,et al.  Pectin–gelatin and alginate–gelatin complex coacervation for controlled drug delivery: Influence of anionic polysaccharides and drugs being encapsulated on physicochemical properties of microcapsules , 2010 .

[3]  J. Hardy,et al.  Structure and technofunctional properties of protein-polysaccharide complexes: a review. , 1998, Critical reviews in food science and nutrition.

[4]  Jin-Chul Kim,et al.  Ethylcellulose microparticles containing chitosan and gelatin: pH-dependent release caused by complex coacervation , 2012 .

[5]  S. Turgeon,et al.  Protein-polysaccharide interactions: phase-ordering kinetics, thermodynamic and structural aspects , 2003 .

[6]  Qingrong Huang,et al.  Composition and rheological properties of beta-Lactoglobulin/pectin coacervates: effects of salt concentration and initial protein/polysaccharide ratio. , 2007, Biomacromolecules.

[7]  P. Carreau,et al.  Viscoelastic properties of chitosan solutions: Effect of concentration and ionic strength , 2006 .

[8]  S. Turgeon,et al.  Gelation of native beta-lactoglobulin induced by electrostatic attractive interaction with xanthan gum. , 2006, Langmuir : the ACS journal of surfaces and colloids.

[9]  M. Nickerson,et al.  Complex coacervation in pea protein isolate–chitosan mixtures , 2011 .

[10]  E. Vavříková,et al.  Chitosan derivatives with antimicrobial, antitumour and antioxidant activities--a review. , 2011, Current pharmaceutical design.

[11]  Adrián A. Perez,et al.  Interactions between milk whey protein and polysaccharide in solution , 2009 .

[12]  M. Zhang,et al.  High-water-content graphene oxide/polyvinyl alcohol hydrogel with excellent mechanical properties , 2014 .

[13]  F. Weinbreck,et al.  Complex coacervation of proteins and anionic polysaccharides , 2004 .

[14]  G. Vladisavljević,et al.  Microencapsulation of oil droplets using cold water fish gelatine/gum arabic complex coacervation by membrane emulsification , 2013 .

[15]  P. Carreau,et al.  Physical gelation of chitosan in the presence of beta-glycerophosphate: the effect of temperature. , 2005, Biomacromolecules.

[16]  F. Agnely,et al.  Proteins, polysaccharides, and their complexes used as stabilizers for emulsions: alternatives to synthetic surfactants in the pharmaceutical field? , 2012, International journal of pharmaceutics.

[17]  E. Morris,et al.  Associative and segregative interactions between gelatin and low-methoxy pectin: Part 1. Associative interactions in the absence of Ca2+ , 2003 .

[18]  E. E. Braudo,et al.  Plant protein interactions with polysaccharides and their influence on legume protein functionality. A review. , 2001, Die Nahrung.

[19]  Rajeev Bhat,et al.  Fish gelatin: properties, challenges, and prospects as an alternative to mammalian gelatins , 2009 .

[20]  H. C. Ferreira,et al.  Influence of ionic strength on the viscosities and water loss of bentonite suspensions containing polymers , 2007 .

[21]  V. Ooi,et al.  Immunomodulation and anti-cancer activity of polysaccharide-protein complexes. , 2000, Current medicinal chemistry.

[22]  M. C. Silva,et al.  Evaluating conditions for the formation of chitosan/gelatin microparticles , 2009 .

[23]  D. Mcclements,et al.  Characterization of β-lactoglobulin–sodium alginate interactions in aqueous solutions: A calorimetry, light scattering, electrophoretic mobility and solubility study , 2006 .

[24]  V. Kiosseoglou,et al.  Whey protein-carboxymethylcellulose interaction in solution and in oil-in-water emulsion systems. Effect on emulsion stability , 2009 .

[25]  P. Williams,et al.  Emulsion stabilization using polysaccharide-protein complexes , 2013 .

[26]  E. Dickinson.  Interfacial structure and stability of food emulsions as affected by protein-polysaccharide interactions. , 2008, Soft matter.

[27]  S. Turgeon,et al.  Protein–polysaccharide complexes and coacervates , 2007 .

[28]  Xiaoquan Yang,et al.  Formation and dynamic interfacial adsorption of glycinin/chitosan soluble complex at acidic pH: Relationship to mixed emulsion stability , 2013 .

[29]  S. Abbas,et al.  The study of pH-dependent complexation between gelatin and gum arabic by morphology evolution and conformational transition , 2013 .

[30]  Qingrong Huang,et al.  Turbidity and rheological properties of bovine serum albumin/pectin coacervates: Effect of salt concentration and initial protein/polysaccharide ratio , 2012 .

[31]  C. Remuñán-López,et al.  Effect of formulation and process variables on the formation of chitosan-gelatin coacervates , 1996 .

[32]  Anthony C. Lee,et al.  Coacervate formation of α-lactalbumin–chitosan and β-lactoglobulin–chitosan complexes , 2009 .

[33]  C. Sánchez,et al.  Self-Assembly of β-Lactoglobulin and Acacia Gum in Aqueous Solvent: Structure and Phase-Ordering Kinetics , 2002 .

[34]  C. Sánchez,et al.  Protein–polysaccharide interactions , 2000 .

[35]  S. Percival,et al.  Preparation, Characterization, and Induction of Cell Apoptosis of Cocoa Procyanidins‐Gelatin‐Chitosan Nanoparticles , 2012, European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V.

[36]  R. Chen,et al.  Effects of ionic strength and pH on the diffusion coefficients and conformation of chitosans molecule in solution , 1999 .

[37]  V. Aswal,et al.  Surface patch binding induced intermolecular complexation and phase separation in aqueous solutions of similarly charged gelatin-chitosan molecules. , 2007, Journal of Physical Chemistry B.

[38]  S. Turgeon,et al.  Protein/polysaccharide complexes and coacervates in food systems. , 2011, Advances in colloid and interface science.