Phospholipid-myosin non-covalent binding in emulsified meat systems: Interfacial behavior and conformational changes

Area of Science:

• Food Science
• Biochemistry
• Materials Science

Background:

• Phospholipids like lecithin are crucial emulsifiers in food systems.
• Myosin, a key meat protein, influences texture and stability.
• Understanding protein-lipid interactions is vital for optimizing processed meat products.

Purpose of the Study:

• To investigate the non-covalent interactions between myosin and lecithin in emulsified meat systems.
• To determine how varying myosin-to-lecithin ratios affect interfacial properties and protein conformation.
• To elucidate the molecular mechanisms underlying lecithin's impact on myosin stability.

Main Methods:

• Systematic variation of myosin and lecithin ratios (M-L 1:0 to 1:2).
• Measurement of interfacial properties, including droplet size and zeta potential.
• Analysis of myosin conformation using spectroscopic techniques (e.g., fluorescence quenching, FTIR).
• Molecular dynamics simulations to model binding interactions.

Main Results:

• Lecithin competitively displaces myosin at oil-water interfaces, reducing droplet size (8.2 to 1.6 μm).
• Interfacial myosin adsorption decreased with increasing lecithin concentration.
• Lecithin binding increased myosin surface hydrophobicity and induced conformational changes (β-sheet enrichment at low ratios).
• Molecular dynamics confirmed spontaneous phosphatidylcholine embedding in myosin's hydrophobic groove, driven by hydrophobic, hydrogen bonding, and electrostatic forces.

Conclusions:

• Lecithin modulates myosin's interfacial behavior and conformation in emulsified meat.
• These interactions enhance myosin's thermal and storage stability.
• The study provides a theoretical basis for leveraging phospholipid-protein interactions in meat emulsion technology.