10th U6+ Consortium of African Universities International Conference

Incorporation of edible insect flours into baked snacks offers nutritional and functional advantages, yet formulation thresholds remain poorly defined. This study quantified the compositional, antioxidant, and sensory responses of wheat biscuits fortified with flours from Gonimbrasia belina and Hermetia illucens. Wheat flour was substituted with H. illucens or G. belina flour at 5, 10, 15, and 20 % (w/w). Proximate composition, colour attributes, antioxidant activity, and sensory acceptability were analysed using standard methods. Protein content increased significantly with insect flour inclusion (p < 0.05), reaching 17.80 % in H. illucens and 19.91 % in G. belina biscuits at the highest substitution levels. H. illucens biscuits exhibited significantly higher fat content than the control (p < 0.05), whereas intermediate inclusion levels did not differ significantly (p > 0.05). Moisture and ash contents were significantly higher in all insect-fortified samples than in the control (p < 0.05). Antioxidant indices increased significantly with substitution level (p < 0.05), with H. illucens formulations exhibiting higher total phenolic content and radical scavenging activity than G. belina. Colour darkening was inclusion-dependent, whereas lower G. belina levels showed limited colour change (p > 0.05). Sensory acceptability decreased significantly at inclusion levels above 10 % (p < 0.05). PCA revealed clear discrimination between formulations, driven by protein, ash, antioxidant indices, and colour, with PC1 and PC2 accounting for 68.97% of total variance. The results demonstrate statistically significant nutritional and antioxidant enhancement alongside inclusion-dependent sensory penalties. These findings define formulation boundaries critical for developing acceptable insect-fortified biscuits.