Extruded whole grain flours as functional ingredient for gluten-free bread: Nutritional,
rheological, structural and textural properties
non-gluten flour; thermomechanical; dough; viscoelastic properties, sprout
This work aimed to use thermoplastic extrusion technology as a pretreatment for whole
grain flours (corn, parboiled brown rice, and sorghum) and the incorporation at 5% of
germinated millet for the production of additive and gluten-free bread. The employed
methodology included flour characterization (chemical composition and particle size
distribution), dough evaluation (pasting, empirical and fundamental rheological
properties), and bread quality characteristics (physical, structural, and textural
measurements). Thermoplastic extrusion allowed to develop the farinographic
consistency and the viscoelastic properties of the dough, as well as an increase in
volume as well as the formation of internal air cells. In addition, the parboiling process
of the rice presented atypical pasting and rheological properties of the dough, which
also affected the quality characteristics of the bread. The incorporation of 5%
germinated millet favored the reduction of hardness and cohesiveness in the crumb,
but in detriment the volume, mainly in the corn bread sample.