Element partitioning of minerals and trace metals in value-added product from insect-mediated valorisation of seafood waste.

Seafood processing generates substantial volumes of shell byproducts that are often underutilized or landfilled, resulting in massive economic and environmental costs. In many coastal regions, limited waste management infrastructure forces processors to rely heavily on landfill disposal, increasing transportation burdens and greenhouse gas emissions. However, processing byproducts such as shell residues is a mineral-rich resource, representing an underexploited opportunity for nutrient recovery and circular reuse. In this study, we evaluated the minerals and trace metal partitioning during the bioconversion of shrimp and crab shell residues using Black Soldier Fly (BSF, Hermetia illucens) larvae. Shell wastes were incorporated into commercial control insect feed at 25-60% inclusion levels and reared for eight days (n = 3 per treatment). Elemental concentrations in feed, larvae, and frass were quantified using ICP-OES to determine the enrichment patterns. The results showed calcium exhibited a substrate-driven response, with strong enrichment in frass (up to 12.15%) and moderate accumulation in larvae. Manganese and zinc showed selective larval uptake at lower inclusion levels, while higher shell inclusion shifted these elements toward frass enrichment. Aluminium, iron, boron, and barium were largely excluded from larval biomass and concentrated in frass. Across both shrimp- and crab-based treatments, frass consistently showed a higher enrichment ratio than larvae for most elements. These findings suggest that BSF bioconversion produces safe, mineral-low larval protein while simultaneously generating mineral-enriched frass for potential use as a slowly mobilized organic soil amendment.