Macrotermes subhylanus flour inclusion in biscuits: Effects on nutritional, sensorial and microbial characteristics

Abstract

As the world's population expands, edible insects have been proposed as a food source that might address issues related to nutrition, health, the environment, and the economy. This study aimed to create a novel biscuit by adding <i>Macrotermes subhylanus</i> (<i>M. Subhylanus</i>) flour to wheat flour in various concentrations (5,10, 15 and 20 %). The moisture content of the insect composite flours varied between 6.83 % and 7.76 %, whereas the moisture content of the biscuits ranged from 2.86 % to 7.90 %. A significant difference (p < 0.05) was noted in the protein content of both the composite flours and biscuits as the concentration of insect flour increased, with values ranging from 15.03 % to 21.52 % for the flours and 17.38 % to 20.63 % for the biscuits. The lightness (L*) of the composite flours significantly decreased (p < 0.05) with higher additions of edible insect flour, whereas the redness (a*) and yellowness (b*) attributes did not show any statistical differences (p > 0.05). The biscuits were generally darker than the composite flours, as indicated by substantially lower L* values. The water activity of the biscuits was between 0.44 and 0.67. Sensory evaluation revealed that the substitution level (up to 15 %) is ideal for preparing acceptable insect-based biscuits. The panellist perceived no significant differences (p > 0.05) in terms of the texture between the insect-enriched biscuits and the control, except for MZ-20. The absence of pathogenic microogranisms in all baked biscuits containing edible insect flour highlights the effectiveness of heat treatment, ensuring that the biscuits meet microbiological safety guidelines. Additionally, <i>Macrotermes subhylanus</i> flour shows promise as a novel functional ingredient for the food industry.