Development of extruded snacks using taro (Colocasia esculenta) and nixtamalized maize (Zea mays) flour blends

Extruded snacks were prepared from flour blends made with taro and nixtamalized (TF–NMF) or non-nixtamalized maize (TF–MF) using a single-screw extruder. A central composite design was used to investigate the effects of taro flour proportion in formulations (0–100 g/100 g) and extrusion temperatures (140–180 °C) on the following indices: expansion (EI), water solubility (WSI), water absorption (WAI) and fat absorption (FAI). Moreover, selected TF–NMF and TF–MF extruded products were partially characterized through proximate chemical analysis, resistant starch, color, pH, water activity, apparent density, hardness, and sensory analysis. Results indicated that EI and WSI of both TF–MF and TF–NMF extrudates were significantly increased by the use of higher proportions of taro flour, while the opposite behavior was observed for the FAI (p < 0.05). Taro flour at higher proportions in both extrudates did not produce a significant change of WAI, while the use of higher extrusion temperatures only caused a significant increase of FAI in TF–MF extrudates (p < 0.05). This study showed that flour mixtures made from taro and nixtamalized maize flour produced puffed extruded snacks with good consumer acceptance.