Potent Antioxidant and Antibacterial Activities of ≤3 Kda Hydrolyzed Sarcoplasmic Proteins from IPB-D1 Chicken

INTRODUCTION:Rising demand for natural bioactive compounds has increased interest in underutilized animal proteins, with sarcoplasmic muscle proteins showing potential for functional peptide production. This study aimed to evaluate the antioxidant and antibacterial activities of sarcoplasmic protein hydrolysates from IPB-D1 chicken, a dual-purpose Indonesian line. METHODS:Sarcoplasmic proteins were hydrolyzed with chymotrypsin, ultrafiltered (MWCO ≤3 kDa), and analyzed for antioxidant and antibacterial activities. RESULTS:Hydrolysates (SHF) showed a sharp decrease in protein concentration (from 49.86 ± 6.19 mg to 0.79 ± 0.05 mg) and disappearance of SDS-PAGE bands, confirming breakdown into smaller peptides. Antioxidant activity increased significantly in SHF compared with the unhydrolyzed fraction (SF). In antibacterial tests, SHF produced larger inhibition zones for all tested bacteria, with the strongest against S. typhi (2.20 ± 1.27 mm) and B. cereus (2.13 ± 0.99 mm), and the lowest against S. aureus (0.36 ± 0.06 mm). Gram-positive bacteria were generally more susceptible than Gram-negative bacteria. DISCUSSION:These results suggest that enzymatic hydrolysis and size reduction (<3 kDa) enhance bioactivity by increasing peptide accessibility and interaction with bacterial membranes. The higher sensitivity of Gram-positive strains is likely related to simpler cell wall structures. CONCLUSION:IPB-D1 chicken sarcoplasmic hydrolysates are a promising source of multifunctional peptides with antioxidant and antibacterial activities. This highlights the potential of IPB-D1 not only as a meat source but also as a strategic genetic resource for sustainable bioprocessing and functional food innovation.