. Influence of pH on viscoelastic properties of heat-induced gels obtained with a ß-Lactoglobulin fraction isolated from bovine milk whey hydrolysates

NATALIA ESTÉVEZ; PABLO FUCIÑOS; VERÓNICA BARGIELA; GUILLERMO PICÓ; NADIA WOITOVICH VALETTI; CLARA ASUNCIÓN TOVAR; MARISA RUA

FOOD CHEMISTRY

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2017 vol. 219 p. 169 - 178

0308-8146

A b-Lactoglobulin fraction (r-bLg) was isolated from whey hydrolysates produced with cardosins fromCynara cardunculus. The impact of the hydrolysis process on the r-bLg structure and the rheologicalproperties of heat-induced gels obtained thereafter were studied at different pH values. Differences wereobserved between r-bLg and commercial b-Lg used as control. Higher values for the fluorescenceemission intensity and red shifts of the emission wavelength of r-bLg suggested changes in its tertiarystructure and more solvent-exposed tryptophan residues. Circular dichroism spectra also supportedthese evidences indicating that hydrolysis yielded an intermediate (non-native) b-Lg state.The thermal history of r-bLg through the new adopted conformation improved the microstructure ofthe gels at acidic pH. So, a new microstructure with better rheological characteristics (higher conformationalflexibility and lower rigidity) and greater water holding ability was founded for r-bLg gel. Theseresults were reflected in the microstructural analysis by scanning electron microscopy.