Valorization of peanut shell polyphenols as natural antioxidants for preserving silver carp mince during refrigerated...

Natural antioxidants derived from agricultural by-products offer a sustainable strategy to inhibit oxidation and extend the shelf life of fish. We evaluated peanut shell extract (PSE), obtained via CO₂-nanobubble sono-extraction, as a natural antioxidant in refrigerated silver carp mince. Compared to butylated-hydroxytoluene (BHT), PSE at 30 mg GAE/100 g was equally effective in preserving color, pH, and water holding capacity over 11 days at 4 °C. PSE dose-significantly outperformed BHT in inhibiting oxidation. It yielded lower lipid oxidation markers (Peroxide value: 0.79 vs 1.15 mmol/kg; TBARS: 0.66 vs 0.93 mg MDA/kg) and reduced protein carbonyl formation (0.66 vs 1.18 mg/mL), while better maintaining protein sulfhydryl groups (4.93 vs 2.34 mol/10⁵ g) by day 11. SDS-PAGE, FTIR, and molecular docking confirmed enhanced protein-polyphenol interactions, suggesting a stabilization mechanism that delays oxidation. Results demonstrate PSE's efficacy at 30 mg GAE/100 g as a sustainable, natural alternative to BHT for refrigerated fish, also valorizing peanut by-products.