Investigation of the sol-gel transition of gelatin using terahertz time-domain spectroscopy

The sol-gel transition temperature of gelatin is determined using viscoelasticity measurement and terahertz time-domain spectroscopy. From the results of the viscoelasticity measurement, the sol-gel transition temperature is determined to be 30–32 °C, and it strongly depended on the concentration. However, terahertz time-domain spectroscopy indicates a particular transition temperature of 36 °C. A distinction of these transition temperatures is attributed to the difference in the structural changes detected by these measurements.