Development of extruded ready-to-eat snacks using pumpkin seed (Cucurbita pepo) and nixtamalized maize (Zea mays) flour blends

Abstract

Extruded ready-to-eat snacks were prepared from flour blends made with pumpkin seed (PSF) and nixtamalized maize (NMF) using a single-screw extruder with a compression screw ratio of 3:1. A central composite rotatable design was used to investigate the effects of the PSF proportion in formulations (0 - 30 g/100 g), feed moisture content (14 - 20 g/100 g) and extrusion temperatures (120 - 180 °C) on the physical properties like expansion index (EI), bulk density (BD), water absorption index (WAI), water solubility index (WSI), hardness (H), pH and total color difference (ΔE). The results indicated that EI, BD and ΔE were significantly affected by increasing the proportion of PSF and BD, whereas increasing ΔE resulted in an opposite effect on EI (P <0.05). Temperature significantly negatively affected (P <0.05) EI and H, while increased moisture content only caused a significant increase (P <0.05) in WAI. Optimal conditions were at an extrusion temperature of 120 °C, feed moisture content of 20 g/100 g and PSF content of 10.36 g/100 g and protein content =11.74 g/100 g. The ready-to-eat snack developed in this research could be considered as a functional food with nutritional and health benefits.