High-Pressure Effects on Gelatin Sol-Gel Transition

Area of Science:

• Biophysics
• Materials Science
• Rheology

Background:

• Gelatin's sol-gel transition is crucial for its applications.
• Understanding pressure effects on gelation is key for novel material processing.
• High hydrostatic pressure (HHP) is a non-thermal processing technique.

Purpose of the Study:

• To investigate the impact of high hydrostatic pressure on the sol-gel transition of gelatin.
• To quantify pressure-induced changes in gelation kinetics and thermodynamics.
• To elucidate the role of pressure in gelatin helix formation and stability.

Main Methods:

• Dynamic Light Scattering (DLS) for monitoring particle size and dynamics.
• DLS-based passive microrheology to assess viscoelastic properties.
• Isothermal and reverse quenching experiments under varying hydrostatic pressures.

Main Results:

• Critical gelation time (t_c) decreased with increasing pressure.
• Critical temperature (T_c) increased with pressure (~0.04 K/MPa).
• Pressure accelerated sol viscosity and gel elastic modulus evolution, indicating faster helix formation and stabilization.

Conclusions:

• High hydrostatic pressure accelerates gelatin sol-gel transition kinetics.
• Pressure stabilizes gelatin helices, enhancing gel strength and slowing melting.
• Rheological changes under pressure directly correlate with helix formation processes.