Feed composition and particle size affect the physicochemical properties of jackfruit-corn extrudates

Abstract

The effect of dried jackfruit powder on the extrusion of cornmeal was investigated for the creation of a naturally flavored and nutritious expanded snack. Both ripe and unripe jackfruit powder of varying particle size (100–1000 μm) were mixed with corn grits (200–1000 μm) to elucidate the effect of macronutrient composition (ripe vs unripe jackfruit), feed composition and particle size on extrusion parameters. Minimum residence time, specific mechanical energy (SME) and product parameters including expansion ratio and hardness were evaluated using a twin-screw corotating extruder. Hindrance to the expansion ratio of the extrudate was observed when ripe or unripe jackfruit was added, due to increased sugar and fibre content, respectively. Ripe jackfruit was found to have increased moisture sorption at higher relative humidity, which is correlated with a higher extrudate water solubility index (WSI). Furthermore, the exact starch-sugar-fibre composition was found to have a larger consequence on expansion than feed particle size. From this study, it was found that both ripe and unripe jackfruit can be used to provide optimal structure, flavour and nutritional content of expanded extrudates.