Reactions between ß-lactoglobulin and genipin: kinetics and characterization of the products.
J Agric Food Chem
; 60(17): 4327-35, 2012 May 02.
Article
em En
| MEDLINE
| ID: mdl-22463374
ABSTRACT
In this paper, we present the first detailed study of the reaction kinetics and the characterization of the products from the endothermic reactions between ß-lactoglobulin and genipin. The effects of the concentration, temperature, and pH were investigated. In the temperature range studied, the reaction was approximately a pseudo-first-order with respect to genipin and 0.22-order and -0.24-order with respect to ß-lactoglobulin for pH 6.75 and 10.5 with corresponding activation energy (E(a)) estimated to be 66.2 ± 3.8 and 9.40 ± 0.36 kJ/mol, respectively. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis studies, validated by matrix-assisted laser desorption ionization-time of flight mass spectrometry, showed the presence of oligomeric, i.e., di-, tri-, quadri-, and pentameric, forms of cross-linked ß-lactoglobulin by genipin at neutral but not alkaline pH; however, an extensive cross-linked network was not observed, consistent with the atomic force microscopy images. It was demonstrated that the reaction temperature and the concentration of genipin but not that of ß-lactoglobulin positively affected the extent of the cross-linking reactions.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Iridoides
/
Lactoglobulinas
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article