Effects of Cereal Byproducts on Antioxidant Capacity of Black Soldier Fly Oil

ABSTRACT Black soldier fly (BSF) larvae efficiently convert organic residues into protein‐ and lipid‐rich biomass, with oil extracted from BSF larvae exhibiting notable antioxidant potential. This study investigated larval growth, oil yield, and antioxidant properties for four feeding substrates made from cereal byproducts: wheat bran, rice bran, sorghum grain, and red quinoa hulls. BSF larvae reared for 7 days on different substrates displayed significant differences in body size, moisture content, and oil extraction efficiency. Wheat‐bran‐fed larvae had the lowest moisture content and largest size, whereas red‐quinoa‐fed larvae exhibited the highest moisture content but smallest size. Sorghum‐fed larvae had the highest oil yield, followed by larvae fed with wheat bran, red quinoa, or rice bran. Oils extracted from larvae reared on the four substrates were analyzed for total phenolic content (TPC) and antioxidant activity using the 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH), 2,2′‐azinobis‐3‐ethylbenzothiazoline‐6‐sulfonic acid (ABTS), and ferric reducing antioxidant power (FRAP) assays. Oil extracted from red‐quinoa‐fed larvae had the highest TPC (79.25 ± 1.04 μg of gallic acid equivalents per gram of oil) and strongest radical scavenging abilities (IC 50 for DPPH = 22.0 ± 1.1 μg/mL, IC 50 for ABTS = 11.6 ± 1.0 μg/mL, and FRAP = 29.24 ± 1.00 μg of vitamin C equivalents per gram of oil), closely followed by oil extracted from rice‐bran‐fed larvae. Pearson correlations indicated that TPC strongly predicted antioxidant performance ( r = −0.995 to 0.962, p < 0.01). Red quinoa optimizes the functional quality of BSF oil. Rice bran offers a balance between oil yield and bioactivity. These findings highlight the effects of feed substrate on BSF oil properties.