The extrusion may improve coeliac bread quality by modifying the functional properties of flour. This study investigates the influence of the substitution of 10% of rice flour by extruded rice flours (three intensities of treatment and two particle sizes) on the characteristics of gluten-free bread (specific volume and texture) at constant consistency. The microstructure and rheology of the doughs obtained and their behaviour during fermentation have also been analysed. The extruded flours increase dough consistency, and the effect is more noticeable with increasing intensities of treatment. The use of extruded flours requires the addition of a larger volume of water to obtain a constant consistency. The addition of extruded flour decreases dough development, producing a lower specific volume and greater bread hardness. This effect is minimized by increasing the particle size. The staling of bread from 24 to 72 hours is less noticeable with a larger particle size.
PRACTICAL APPLICATIONS
This study evidences that the use of extruded flours in rice bread making allows increasing dough hydration and therefore the bread yield while decreasing bread staling. However, the correct selection of extrusion treatment and flour particle size is essential to achieve appropriate results, being preferable the use of coarse flours with more intense extrusion treatment.
