Tina Sinethemba Bebe, Vusi Vincent Mshayisa, Lusani Norah Vhangani, Mpho Edward Mashau
Mopane worms (Gonimbrasia belina) are a good source of key nutrients and have made significant contributions to the diets of sub-Saharan African communities. The aim of this study was to evaluate yellow mopane worm powder (MWF) as a functional ingredient in wheat-based composite flours by characterizing the nutritional, physicochemical, techno-functional, pasting, and thermal properties of wheat flour (WF), MWF, and composite flours containing 5%, 10%, 15%, and 20% MWF substitution. Protein, ash, and fat contents varied across samples, with ranges of 14.99%-43.39%, 1.05%-7.97%, and 0.18%-5.22%, respectively. While moisture and energy content depicted no significant differences (p > 0.05). Enrichment with MWF enhanced the mineral profile of the composite flours, particularly for Na, K, P, Zn, and Fe, and increased essential amino acid content, including lysine (0.58-1.55 g/100 g), a key limiting nutrient in cereal-based diets. Color analysis revealed significant increases (p < 0.05) in lightness, redness, and yellowness with higher MWF incorporation. Bulk density (0.57-0.76 g/mL), water activity (0.56-0.63), and pH (5.77-6.12) remained within acceptable ranges. MW15% and MW20% demonstrated significantly improved oil-binding capacity and foaming stability, while MWF exhibited the highest water-binding capacity. Conversely, foaming capacity, emulsifying capacity, and emulsifying stability decreased with increasing MWF content. Pasting properties indicated that MW5%, MW10%, and MW15% had peak, trough, and set viscosity profiles comparable to those of WF, suggesting their suitability for dough-based applications. Thermal analysis (TGA and DSC) revealed strong thermal stability in MWF, with both endothermic and exothermic transitions observed across all samples. FT-IR spectroscopy confirmed prominent amide I and II bands in high-protein MWF, contrasting with weaker protein-associated absorption in WF.