Isolation of bovine β-lactoglobulin from complexes with chitosan

A simple, economical and non-toxic method is described for the solubilization of undenatured β-lactoglobulin (β-lg) from complexes with chitosan. The effect of pH (8-10), ionic strength (0.08-0.3 m) and volume ratio between sodium acetate solutions and whey on the dissociation of β-lg-chitosan compl...

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Bibliographic Details
Authors: Montilla, Antonia, Casal, Enriqueta, Moreno, F. Javier, Belloque, Josefina, Olano, Agustín, Corzo, Nieves
Format: article
Status:Versión enviada para evaluación y publicación
Publication Date:2007
Country:España
Institution:Consejo Superior de Investigaciones Científicas (CSIC)
Repository:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/155043
Online Access:http://hdl.handle.net/10261/155043
Access Level:Open access
Keyword:Electrostatic interactions
Cheese whey
β-lactoglobulin
Chitosan
Description
Summary:A simple, economical and non-toxic method is described for the solubilization of undenatured β-lactoglobulin (β-lg) from complexes with chitosan. The effect of pH (8-10), ionic strength (0.08-0.3 m) and volume ratio between sodium acetate solutions and whey on the dissociation of β-lg-chitosan complexes was evaluated. Following a single extraction step with the addition of 10 mL of 0.1 m sodium acetate solution at pH 9 to the β-lg-chitosan complexes obtained from 1 mL of cheese-whey, a recovery of 90% of β-lg with a protein purity of 95% was achieved, suggesting that electrostatic interactions play a key role in the complexation of β-lg with chitosan. The presence of free chitosan in solution was ruled out according to gas chromatography with flame-ionization detector analysis after acid hydrolysis. NMR spectroscopy showed that the recovered β-lg after further dialysis had structural features very similar to the native protein.