Polyphenol-Enriched Black Soldier Fly Larvae (Hermetia illucens) Meal Improves Lipid Quality and Delays Oxidative Deterioration of Refrigerated Broiler Breast Meat

This study investigated whether black soldier fly larvae meal (BSFL; Hermetia illucens L.) produced on polyphenol-rich agro-industrial by-products could enhance broiler meat lipid quality and oxidative stability during refrigerated storage. A total of 200 one-day-old Arbor Acres broilers were allocated to five dietary treatments: control diet, 5% standard full-fat BSFL meal, 10% standard full-fat BSFL meal, 10% full-fat BSFL meals produced on olive leaf and spent tea residues, and 10% defatted BSFL meal. Compared with standard full-fat BSFL meal, the olive leaf–spent tea BSFL meal showed markedly higher total phenolic content (6.74 vs. 1.82 mg GAE/g DM), DPPH radical-scavenging activity (54.80 vs. 22.40%) and ABTS antioxidant capacity (38.20 vs. 15.60 umol TE/g DM), together with lower peroxide value (1.46 vs. 2.38 meq O2/kg lipid) and TBARS (0.24 vs. 0.39 mg MDA/kg meal). Also, when compared with 10% standard full-fat BSFL meal, the olive leaf–spent tea BSFL meal improved final body weight (2592.8 vs. 2511.6 g) and feed conversion ratio (1.53 vs. 1.58). Breast meat from this group contained higher oleic acid (40.52 vs. 37.48%) and a-linolenic acid (1.72 vs. 1.29%), while showing a lower n-6/n-3 ratio (11.81 vs. 14.49) and thrombogenicity index (0.78 vs. 0.92). After 10 days of refrigerated storage, breast meat from birds fed the polyphenol-enriched BSFL meal showed markedly lower oxidative deterioration, as indicated by reduced TBARS values (0.60 vs. 1.12 mg MDA/kg), protein carbonyl formation (2.16 vs. 3.35 nmol/mg protein) and hexanal abundance (5.10 vs. 11.90 a.u.; internal-standard-normalized peak area). This treatment also better-preserved redness, as reflected by higher CIE values (3.52 vs. 2.40), compared to the control group. Overall, these results suggest that substrate-tailored BSFL meal may serve as a functional feed ingredient for improving the lipid quality of broilers’ breast meat and delaying oxidation-driven quality deterioration during refrigerated storage.