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

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.Financial support of Spanish Scientific Research Council (CSIC), the Spanish Ministry of Economy and Sustainability (Project AGL2014-52928-C2-1-R), the European Regional Development Fund (FEDER) and the Generalitat Valenciana (Project Prometeo 2012/064). H. Bourekoua acknowledges the financial support of Institute of Nutrition, Food and Agrofood Technology (I.N.A.T.A.A.).Peer reviewe