Influence of repeated extrusions on some properties of non-conventional spaghetti

The influence of the re-extrusion (repeated extrusion) number on the rheological properties of non-conventional doughs, mechanical and sensorial characteristics of dry spaghetti was investigated. Moreover, the dough gelatinization degree was also evaluated. Amaranth, oat and quinoa flours were used to produce the spaghetti samples. Twelve non-conventional spaghetti samples were manufactured varying the re-extrusion number. The rheological properties of doughs were determined using a capillary rheometer, the mechanical characteristics of dry spaghetti by a dynamic mechanical analyzer and the sensorial parameters by a trained panel. The re-extrusion number affected the extensional and shears viscosity of amaranth, oat and quinoa dough samples. The breaking strength of dry non-conventional spaghetti increased with the increase of the re-extrusion number for amaranth and oat. The dough gelatinization degree of the quinoa and oat significantly increased with the re-extrusion, whereas no influence of re-extrusion was found for the amaranth dough. Moreover, the re-extrusion number improved sensorial color and homogeneity for oat and quinoa dry spaghetti and had no effects on the sensorial characteristics of all cooked spaghetti.