TY - JOUR
T1 - Effect of heat on rheology, surface hydrophobicity and molecular weight distribution of glutens extracted from flours with different bread-making quality
AU - Stathopoulos, Costas E.
AU - Tsiami, Amalia A.
AU - David Schofield, J.
AU - Dobraszczyk, Bogdan J.
N1 - Funding Information:
Costas Stathopoulos gratefully acknowledges the financial support provided by DEFRA (MAFF), LINK project AFQ122. We would also like to thank Martin Albertini, Weston Research Laboratories Ltd., Maidenhead, UK for providing the analytical and baking data on the flours.
PY - 2008/3
Y1 - 2008/3
N2 - Gluten was extracted from flours of several different wheat varieties of varying baking quality. Creep compliance was measured at room temperature and tan δ was measured over a range of temperatures from 25 to 95 °C. The extracted glutens were heat-treated for 20 min at 25, 40, 50, 60, 70 and 90 °C in a water bath, freeze-dried and ground to a fine powder. Tests were carried out for extractability in sodium dodecyl sulphate, free sulphydryl (SH) groups using Ellman's method, surface hydrophobicity and molecular weight (MW) distribution (MWD) using field-flow fractionation and multi-angle laser light scattering. With increasing temperature, the glutens showed a decrease in extractability, with the most rapid decreases occurring between 70 and 90 °C, a major transition in tan δ at around 60 °C and a minor transition at 40 °C for most varieties, a decrease in free SH groups and surface hydrophobicity and a shift in the MWD towards higher MW. The poor bread-making variety Riband showed the highest values of tan δ and Newtonian compliance, the lowest content of free SH groups and the largest increase of HMW/LMW with increasing temperature. No significant correlations with baking volume were found between any of the measured parameters.
AB - Gluten was extracted from flours of several different wheat varieties of varying baking quality. Creep compliance was measured at room temperature and tan δ was measured over a range of temperatures from 25 to 95 °C. The extracted glutens were heat-treated for 20 min at 25, 40, 50, 60, 70 and 90 °C in a water bath, freeze-dried and ground to a fine powder. Tests were carried out for extractability in sodium dodecyl sulphate, free sulphydryl (SH) groups using Ellman's method, surface hydrophobicity and molecular weight (MW) distribution (MWD) using field-flow fractionation and multi-angle laser light scattering. With increasing temperature, the glutens showed a decrease in extractability, with the most rapid decreases occurring between 70 and 90 °C, a major transition in tan δ at around 60 °C and a minor transition at 40 °C for most varieties, a decrease in free SH groups and surface hydrophobicity and a shift in the MWD towards higher MW. The poor bread-making variety Riband showed the highest values of tan δ and Newtonian compliance, the lowest content of free SH groups and the largest increase of HMW/LMW with increasing temperature. No significant correlations with baking volume were found between any of the measured parameters.
KW - Baking quality
KW - Creep recovery
KW - Field-flow fractionation
KW - Gluten
KW - Heat effect
KW - Molecular weight distribution
KW - Rheology
KW - Surface hydrophobicity
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U2 - 10.1016/j.jcs.2007.03.002
DO - 10.1016/j.jcs.2007.03.002
M3 - Article
AN - SCOPUS:39649119647
SN - 0733-5210
VL - 47
SP - 134
EP - 143
JO - Journal of Cereal Science
JF - Journal of Cereal Science
IS - 2
ER -