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Pressure-induced phase transitions in triacylglycerides
Peter Ferstl1, Sebastian Gillig, Christoph Kaufmann
1Technische Universität München, Center of Life and Food Sciences Weihenstephan, Freising, Germany. ferstl@wzw.tum.de
Annals of the New York Academy of Sciences
|March 18, 2010
Summary
High hydrostatic pressure significantly increases triacylglycerides (TAGs) melting points nonlinearly. Pressure-induced solidification shows induction times similar to temperature-driven crystallization, suggesting unique crystalline structures may form.
Area of Science:
- Physical chemistry
- Materials science
- Thermodynamics
Background:
- Melting point of triacylglycerides (TAGs) is influenced by fatty acid composition, crystalline structure, and thermal history.
- High hydrostatic pressure's effect on TAG melting points and solidification kinetics is not well understood.
Purpose of the Study:
- To investigate the impact of high hydrostatic pressure on the melting point and solidification of triacylglycerides.
- To compare pressure-induced solidification kinetics with temperature-induced crystallization.
Main Methods:
- Investigated TAGs under pressures up to 450 MPa in a temperature-controlled cell.
- Utilized perpendicular light scattering, transmission, and a high-pressure polarized-light microscope to observe phase transitions.
- Measured melting points and induction times for pressure-induced solidification.
Main Results:
- Observed a significant, nonlinear increase in TAG melting points with increasing hydrostatic pressure.
- Documented a dramatic increase in delay time for pressure-induced solidification, analogous to supercooling effects.
- Found pressure-dependent induction times for solidification similar to temperature-driven crystallization.
Conclusions:
- High hydrostatic pressure substantially elevates TAG melting points.
- Pressure-induced solidification exhibits kinetic behaviors comparable to temperature-induced crystallization.
- Superpressuring may yield distinct crystalline structures compared to supercooling TAGs.
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