Phosphorylated Salmon bone polypeptides: enhancing stability and antimicrobial activity through zinc chelation

Area of Science:

• Marine biotechnology
• Biomaterials science
• Nutritional biochemistry

Background:

• Salmon bones represent a valuable marine waste stream with untapped bioactive potential.
• Phosphorylation and metal chelation can enhance the functional properties of biomolecules.

Purpose of the Study:

• To develop and characterize phosphorylated salmon bone peptides chelated with zinc (P-SBPs-Zn).
• To evaluate the stability, digestibility, antibacterial activity, and safety of P-SBPs-Zn for potential food applications.

Main Methods:

• Salmon bone peptides (SBPs) were phosphorylated at various pH levels.
• Structural analysis using Fourier-transform infrared spectroscopy, fluorescence spectroscopy, and CD spectroscopy.
• Zinc chelation efficiency, stability, digestibility, antibacterial activity, and cell safety assessments were performed.

Main Results:

• Phosphopeptide-zinc chelates at pH 4 (P-SBPs4-Zn) showed superior solubility and zinc-binding capacity (86.15 ± 0.47 mg/g zinc).
• P-SBPs4-Zn exhibited excellent stability and digestibility under simulated gastrointestinal conditions.
• Significant antibacterial effects against Escherichia coli and Staphylococcus aureus were observed, attributed to membrane disruption.
• Safety assessments confirmed biocompatibility with Caco-2 and RAW 264.7 cells.

Conclusions:

• P-SBPs4-Zn is a highly effective, stable, and biocompatible zinc supplement derived from marine waste.
• This novel phosphopeptide-zinc complex demonstrates potential as an antibacterial agent and functional ingredient in food processing.