Abstract

Black soldier fly (BSF) larvae (Hermetia illucens) might be an advantageous option for recycling fish waste for obtaining n-3-fatty acid-rich foods. To investigate the effects of consuming fish waste (an n-3-fatty acid-rich by-product) on the fatty acid (FA) profiles of BSF, larvae were assigned to experimental feeding systems according to the time fish waste was eaten before slaughtering: BSFc-control (without eating fish) and BSF1d, BSF2d, BSF4d, BSF6d, BSF8d, BSF10d and BSF12d (1, 2, 4, 6, 8, 10 and 12 days eating fish, respectively). The percentage of n-3 polyunsaturated fatty acids (PUFAs) increases significantly (P < 0.001) from 4.32 in BSFc to 14.8% in BSF12d. Larval biomass was notably enriched in both eicosapentaenoic (EPA) (up to 7.2%) (P < 0.001) and docosahexaenoic (DHA) (up to 4.9%) (P < 0.001) fatty acids, while the consumption time of fish waste increased, and the n-6:n-3 ratio and both the atherogenicity (AI) and thrombogenicity (TI) indices were reduced (P < 0.001). The maximum percentage of EPA + DHA (12.2% of total fatty acids) (P < 0.001) was obtained at 12 days. The recommended daily intake of both n-3 PUFAs for humans could be satisfied with 150 g of a 12-day-feed larval meal.