A Dual Strategy for Innovative Extraction and Nutritional Efficacy of Black Soldier Fly Larvae Oil

Amid the intensifying global mandate for sustainable aquafeed strategies, this study investigates the functional efficacy and biochemical implications of black soldier fly larvae oil (BLO), extracted via recently approved patent method depending on cold-aqueous process, as a substitute for conventional fish oil (FO) in zebrafish (Danio rerio) diets. The refined extraction technique, representing an advancement over traditional aqueous methodologies, was engineered to selectively preserve bioactive lipid fractions while minimizing environmental footprint and processing residues. Over a 28-day feeding period, adult zebrafish were allocated into triplicate groups and fed diets comprising 0%, 50%, and 100% substitution of FO with BLO and growth, lipid composition, and dietary fatty acid profiles of both diets and flesh were rigorously evaluated. Zebrafish fed the BLO100 diet exhibited the most pronounced somatic growth (2.47 ± 0.01 g), significantly elevated specific growth rates (3.88 ± 0.82% day−1), and the most efficient feed conversion, without compromising survival. Flesh lipid analysis revealed a substantial enrichment in saturated fatty acids—most notably lauric acid (C12:0)—corresponding to increasing dietary BLO levels. Although dietary EPA and DHA levels were reduced, DHA concentrations in fish tissues remained comparable to those of the control group, indicating a compensatory capacity mediated by endogenous elongation and desaturation pathways. These findings substantiate the dual potential of BLO as both a nutritionally viable lipid source and a vector for enhancing aquafeed sustainability. The cold-aqueous extraction method demonstrated here underscores a pivotal advancement in green lipid processing, aligning oil quality with ecological stewardship. This integrative approach not only reinforces BLO’s candidacy as a strategic fish oil substitute but also delineates a pathway toward scalable, species-adapted feed innovation. Future investigations should prioritize the modulation of fatty acid profiles through dietary and extraction optimization to fully realize the translational potential of insect-derived lipids in aquaculture.