Temperature-induced phase change in a fat. A study by electron spin resonance

Area of Science:

• Food science and technology
• Physical chemistry of fats and oils

Background:

• Understanding the physical properties of lard is crucial for its application in food processing.
• Fractionation of lard yields distinct solid and liquid phases with different triglyceride compositions.

Purpose of the Study:

• To investigate the physical changes in lard and its fractions induced by temperature.
• To study the behavior of a probe molecule within lard across a wide temperature range.

Main Methods:

• Electron Spin Resonance (ESR) spectroscopy
• Differential Scanning Calorimetry (DSC)
• Rheological measurements
• Fractionation of lard at 15°C

Main Results:

• Probe mobility correlated with the melting of low-melting point glycerides.
• Above the melting point, probe mobility reflected the viscosity of the liquid fat.
• Probe mobility was temperature-dependent and consistent across different lard fractions at equivalent temperatures.

Conclusions:

• The physical state and triglyceride composition of lard fractions influence probe mobility.
• ESR provides insights into the dynamic behavior of fats and their phase transitions.