Cooking quality, nutritional and antioxidant properties of gluten-free maize – orange-fleshed sweet potato pasta produced by extrusion

Abstract

Maize and orange-fleshed sweet potato (OFSP) composite (100:0, 50:50, 70:30, 80:20) flours were extruded into pasta using a twin-screw extruder. The cooking quality, textural and nutritional properties of the pasta were assessed. An increase in the proportion of OFSP flour added increased the cooking loss but decreased cooking time and water absorption capacity of pasta. The dietary fibre in the OFSP flour caused a loosening of the compact structure of the pasta, disrupting the compact protein-starch matrix of maize, resulting in higher cooking loss and sticky pasta. Extruded pasta had low cooking time due to pre-gelatinized starch, which promotes greater water absorption and heat dissemination during cooking. Extruded pasta samples had lower betacarotene, probably due to cis-trans isomerization, fragmentation, and oxidative decomposition, but the pasta showed higher antioxidant properties, likely due to Maillard reaction and caramelization products with reducing properties. These results indicate that OFSP can be composited with maize flour and extruded to produce good quality and nutritious gluten-free pasta.