Ultrasonic-Assisted Enzyme Hydrolysis of Chicken By-Products: Optimization, Peptide Mapping and Antioxidative Efficacy by In-vitro and In-silico Approach

Abstract

This study investigates the ultrasound-assisted enzymatic extraction of collagen hydrolysates (CH) from chicken skin, heads, and feet, aiming to generate bioactive peptides with potent antioxidant activity. Process optimization involved acetic acid pre-treatment, ultrasonication (39 kHz), and enzymatic hydrolysis using collagenase, followed by ultrafiltration (10 kDa). The optimized treatment (T2) yielded hydrolysates with a high degree of hydrolysis (85.31%) and protein content (11.73 g/dL). SDS-PAGE revealed predominantly low-molecular-weight peptides, indicative of effective collagen breakdown. Antioxidant capacity, measured via DPPH and ABTS+ assays, was significantly elevated in T2 (76.38% and 91.41%, respectively). Peptidomic profiling was conducted using LC-ESI-MS/MS on a QTOF mass spectrometer, enabling the identification of numerous peptide sequences. In-silico bioactivity prediction using the BIOPEP database and Peptide Ranker algorithm revealed multiple sequences with high antioxidant potential, particularly short-chain peptides rich in hydrophobic and aromatic residues. The integration of advanced proteomic tools and bioinformatic analyses confirmed the efficacy of ultrasound-assisted enzymatic hydrolysis in producingfunctionally relevant peptides. These findings support the valorization of poultry by-products as a sustainable source ofantioxidative peptides for potential applications in food and health sectors.