TY - JOUR
T1 - Caustic-induced gelation of β-lactoglobulin
AU - Mercadé-Prieto, Ruben
AU - Paterson, William R.
AU - Wilson, D. Ian
PY - 2008/8
Y1 - 2008/8
N2 - The gelation kinetics of β-lactoglobulin (βLg) solutions has been determined in the alkaline regime over a wide range of protein concentrations, gelling temperatures and gelation pH (pHgel), set using NaOH. The behaviour is compared with caustic-induced gelation of whey protein concentrate and the alkaline dissolution of heat-induced whey gels. The gelation time decreases significantly between neutral conditions and pHgel 9, because of the activation of the free cysteine groups and displacement to the monomeric form, and between pHgel 10 and 11, due to the base denaturation of βLg. Both transitions are associated with a significant decrease in the activation energy of gelation. At pHgel >11.5 the gelation time is observed to increase with pHgel, owing to destruction of interprotein crosslinks. These results are consistent with the recently reported observation that a minimum pH for the dissolution of βLg gels and aggregates exists around 11.6 [Biomacromolecules8 (2007) 1162]. This phenomenon has been assigned to the destruction of non-covalent interactions that would inhibit the final percolation of the gel.
AB - The gelation kinetics of β-lactoglobulin (βLg) solutions has been determined in the alkaline regime over a wide range of protein concentrations, gelling temperatures and gelation pH (pHgel), set using NaOH. The behaviour is compared with caustic-induced gelation of whey protein concentrate and the alkaline dissolution of heat-induced whey gels. The gelation time decreases significantly between neutral conditions and pHgel 9, because of the activation of the free cysteine groups and displacement to the monomeric form, and between pHgel 10 and 11, due to the base denaturation of βLg. Both transitions are associated with a significant decrease in the activation energy of gelation. At pHgel >11.5 the gelation time is observed to increase with pHgel, owing to destruction of interprotein crosslinks. These results are consistent with the recently reported observation that a minimum pH for the dissolution of βLg gels and aggregates exists around 11.6 [Biomacromolecules8 (2007) 1162]. This phenomenon has been assigned to the destruction of non-covalent interactions that would inhibit the final percolation of the gel.
KW - Alkali
KW - Gelation
KW - β-lactoglobulin
UR - http://www.scopus.com/inward/record.url?scp=47649116233&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2621.2007.01643.x
DO - 10.1111/j.1365-2621.2007.01643.x
M3 - Article
AN - SCOPUS:47649116233
SN - 0950-5423
VL - 43
SP - 1379
EP - 1386
JO - International Journal of Food Science and Technology
JF - International Journal of Food Science and Technology
IS - 8
ER -