Secondary products and bioactive compounds of Hermetia illucens: Extraction, chemical properties, and potential application of frass

Frass, a mixture of larval excretions, exuviae, and residual feedstock, is a valuable by-product generated from waste bioconversion using the larvae of Hermetia illucens. As a secondary product of black soldier fly (Hermetia illucens) rearing, frass functions effectively as an organic fertilizer. Rich in essential plant nutrients and beneficial microorganisms, it enhances soil fertility, promotes crop productivity, and reduces dependency on synthetic fertilizers, thus supporting sustainable agricultural practices. This organic by-product aligns seamlessly with circular economy principles, offering an innovative solution for recycling organic waste. Its dual role in waste valorization and soil improvement establishes frass as a key resource for developing environmentally sustainable and highly efficient agricultural systems.