Developing gluten free bakery improvers by hydrothermal treatment of rice and corn flours

• Hydrothermally treated slurry from rice and corn flours were used as bakery improvers.
• An experimental design was used to optimize water hydration and amount of improver.
• Hydrothermally treated flours increased dough consistency.
• Gluten free breads from corn/field bean or rice/field bean semolina were obtained.

The impact of hydrothermal treatment of rice and corn flours on their potential as gluten free bakery improvers was tested. Hydrothermal treatment of flours was carried out by suspending flours in water on the basis of 5/1 (w/w) and heated until 65 °C. Corn or rice semolina supplemented by field bean semolina in ratio of 2/1 (w/w) were used for obtaining protein enriched gluten free breads, where improvers functionality was tested. Two central composite designs involving water hydration levels (X1, X′1) and the level of hydrothermally treated rice or corn flours (X2, X′2) were used. Instrumental analyses of breads (specific volume, moisture content, crumb texture and height/width ratio) were carried out to assess the impact of experimental factors. Results showed that hydrothermal treatment of rice or corn flours affected in different extent the bread properties, increasing the specific volume of breads and H/W ratio, and decreasing the hardness and chewiness of both types of breads.The optimum formulation for rice/field bean bread contained 7.59 g/100 g treated rice flour and 96.66 g/100 g water, and for corn/field bean bread the optimum included 4.73 g/100 g treated corn and 78.81 g/100 g water. Optimized breads were found acceptable according to color and texture structure.