Jj. Kokelaar et al., STRAIN-HARDENING PROPERTIES AND EXTENSIBILITY OF FLOUR AND GLUTEN DOUGHS IN RELATION TO BREADMAKING PERFORMANCE, Journal of cereal science, 24(3), 1996, pp. 199-214
The mechanical properties of flour-water doughs and hydrated gluten of
different wheat cultivars were determined. Measurements were performe
d at small deformations (dynamic measurements) as well as at large def
ormations (biaxial extension measurements). Results of dynamic measure
ments of hour doughs related poorly to breadmaking quality. For hydrat
ed gluten doughs, all having the same water content, it was found that
glutens from wheat cultivars with good baking quality had higher valu
es for the storage modulus, G', and lower values for the loss tangent.
The relevant type of deformation around an expanding gas bubble is bi
axial extension. Wheats with a good baking performance exhibited great
er strain hardening and greater extensibility. The differences in stra
in hardening observed at 20 degrees C were also present at 55 degrees
C. No clear effects of NaCl or emulsifiers on the biaxial extension pr
operties of flour dough were found. Extensograms as well as Alveograms
from the flour doughs showed that, in general, good baking flours exh
ibited stronger resistance to extension and a greater extensibility, b
ut differences found were not directly related to the results of the b
aking tests. The results indicate that the baking performance of dough
is related to a combination of at least three different theological c
haracteristics. (C) 1996 Academic Press Limited