Quality assessment of gluten-free pasta prepared with a brown rice and corn meal blend via thermoplastic extrusion

• Brown rice is a more nutritious alternative for developing gluten-free pasta.
• The extrusion-cooking process caused strong interactions among the ingredients.
• The feed moisture caused important changes in the quality of the pasta.
• Pasta produced with 60 g/100 g (brown rice) exhibited better texture and acceptability.

The development of gluten-free pastas made with brown rice (BR) and corn meal (CM) was proposed. A 32 central composite rotation design was used to evaluate the effects of the extrusion variables, i.e., temperature, feed moisture and CM content, on the pasting properties and cooking quality of the extrudates. Sensory factors, texture and chemical composition were also analysed to determine the best treatments. The pasting properties allowed verification of the transformations/interactions among the components of the dough after the extrusion process. An increase of the feed moisture content (up to 43.4 g/100 g) caused an increase in cooking loss, but for CM flour (up to 46.8 g/100 g), this increase caused an increase in cooking time. The temperature levels did not influence the cooking characteristics. The pasta with the highest BR flour content (87 g/100 g) had higher contents of lipids and fibre, as well as better mineral and amino acid profiles. The pasta produced with a ratio of 40:60 (CM:BR), 30 g/100 g of moisture content, and at 70 °C received better evaluations with respect to texture (sensory and instrumental) compared with pasta made with a ratio of 13.2:86.8 (CM:BR) and 35 g/100 g moisture content at 80 °C.