Mineral and Antinutrient Content of High Quality Cassava-Tigernut Composite Flour Extruded Snack

Abstract

This study investigated the mineral and antinutrient composition of extruded snack produced from different blends of high quality cassava and tigernut flour. The extruded snacks were produced using a single-screw laboratory extruder at constant feed moisture (27%), screw speed (60 rpm) and barrel temperature (80C). It was observed that the extrudates had higher values for mineral composition (phosphorus, calcium, magnesium, potassium and iron) than the composite flour which showed that extrusion cooking improves the absorption of the minerals. The antinutrient (tannin, phytate, saponin, oxalate, alkaloids and total phenolic) contents of all the flour blends significantly (P < 0.05) increased with tigernut flour inclusion. Extrusion cooking resulted in significant (P < 0.05) reduction in the antinutrients of the extrudates. The study showed that extrusion cooking reduced the antinutritional factors thereby increasing the bioavailabilty of minerals. Also, the minerals were not affected by the extrusion cooking process probably because minerals are heat stable. Practical Applications Findings from this study have potentials to increase the productivity and value addition to tigernut, an underutilized plant specie. The snack produced is also a good alternative gluten free product.