Thermal Hysteresis of Infrared Spectra of Corn Starch/Water Systems

Infrared spectra of O.10mm thick corn starch-water systems were measured with a FTIR spectrometer. With increasing temperature from 25 to 95°C, the absorbance at 2700cm⁻¹ decreased abruptly around 80°C due to sol-gel process. The absorbance of the gel increased by freezing and returned to the unfrozen value after thawing. The present method of using the absorbance at 2700cm⁻¹ is promising to investigate the interaction between water and starch including sol-gel process.