Effect of extrusion cooking and cricket flour ingredient on the sensory and functional properties of staple cereal and legume flours

Abstract

Due to the increasing global population and unsustainable meat production, the future supply of animal-derived protein is predicted to be insufficient. This will lead to exacerbation of the current unacceptable high levels of protein energy malnutrition & micronutrient deficiencies, especially amongst children under five years in Uganda. Currently, edible insects such as crickets are considered a potential source of protein for the resource poor individuals who largely depend on cereals for calories in developing countries. This study therefore aimed at increasing the availability of animal protein to the Ugandan population through incorporating edible insects into staple flours. The study focused on determining the effects of extrusion cooking and insect flour inclusion on the functional and sensory properties of maize, millet and soy flour blended with cricket flour at 0%, 5%, 10%, 15% & 20% levels. Increase in the levels of insect flour inclusion reduced the Bulk Density, water solubility Index & swelling power of both extruded and non-extruded flour blends. However, Water & Oil absorption capacities increased in non-extruded flour blends with increase in insect flour inclusion. On the other hand, there was a decline in water & oil absorption capacity of the extruded flours with increased insect flour inclusion. The mean scores of sensory attributes for the porridges generally reduced with increase in the levels of cricket flour inclusion for both extruded and non-extruded flour blends, with the least scores observed at 15%& 20% levels of cricket flour substitution. Overall, the mean scores of the sensory attributes of porridge blends from extruded flour blends were not significantly(P<0.05) different from the ones from non-extruded counterparts. Porridges from extruded maize and millet flour blends registered the highest mean overall acceptability with 5% insect flour substitution while porridge from extruded soy blend registered the highest score at 10% cricket flour inclusion. For porridges developed from non-extruded flours, their overall acceptability mean scores kept reducing all through from 0% to 20% cricket flour inclusion for maize, millet and soy flour. The Water Absorption Capacity, Oil Absorption Capacity, Water Solubility Index of the extruded maize, millet and soy flour blends with cricket flours were found to be significantly (P<0.05) higher than those of non-extruded counterparts. Bulk density of non-extruded flours was found to be significantly (p<0.05) higher than the extruded flour blends whereas the swelling capacity of both flours showed no significant difference. The pasting properties of the extruded flour blends were significantly lower than the non-extruded flour blends, except the pasting time and pasting temperature for the extruded millet and soy flour that were found to be slightly higher than the non-extruded counterpart. Extruded maize flour with 5% cricket flour had the lowest peak time of 1.1 minutes and lowest pasting temperature of 50.1℃