Breads with a specific volume up to, and beyond, that of conventional
wheat bread can be made with rice flour (which does not contain gluten
) by incorporation of hydroxypropylmethylcellulose (HPMC) and ispaghul
a husk (isabgol) from Plantago ovata Forsk. Isabgol disperses to a fib
rillar 'weak gel' network stable over the temperature range of proving
(fermentation with yeast) and initial heating in the baking oven. Wea
kening of the isabgol network at higher temperature is accompanied by
thermal gelation of HPMC, so that the overall network strength (storag
e modulus, G') remains virtually constant, and the gas-cell structure
developed during proving is retained. Gelation of HPMC (and of methylc
ellulose) involves two distinct processes which we suggest correspond
to partial dissociation and subsequent aggregation of cellulosic 'bund
les' present in the solution state at low temperature, a mechanism dir
ectly analogous to the thermal gelation of globular proteins.