Gum arabic-chitosan complex coacervation.
The formation of electrostatic complexes of gum Arabic (GA) with chitosan (Ch), two oppositely charged polysaccharides, as a function of the biopolymers ratio (RGA/Ch), total biopolymers concentration (TBconc), pH, and ionic strength, was investigated. The conditions under which inter-biopolymer complexes form were determined by using turbidimetric and electrophoretic mobility measurements in the equilibrium phase and by quantifying mass in the precipitated phase. Results indicated that optimum coacervate yield was achieved at RGA/Ch = 5, independently of TBconc at the resulting pH of solutions under mixing conditions. High coacervate yields occurred in a pH range from 3.5 to 5.0 for RGA/Ch = 5. Coacervate yield was drastically diminished at pH values below 3.5 due to a low degree of ionization of GA molecules, and at pH values above 5 due to a low solubility of chitosan. Increasing ionic strength decreased coacervate yield due to shielding of ionized groups.
Espinosa-Andrews
Hugo
H
DIPH and DBT, Universidad Autónoma Metropolitana-Iztapalapa, San Rafael Atlixco 186, Mexico City 09340, Mexico.
Báez-González
Juan G
JG
Cruz-Sosa
Francisco
F
Vernon-Carter
E Jaime
EJ
D048271:Chitosan / Q000737:chemistry*; D004586:Electrophoresis; D006170:Gum Arabic / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D009391:Nephelometry and Turbidimetry; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D012965:Sodium Chloride / Q000737:chemistry
D011108:Polymers; D012965:Sodium Chloride; D006170:Gum Arabic; D048271:Chitosan