Modulated-temperature differential scanning calorimetric and dynamic mechanical analyses and dielectric spectroscopy were used to investigate the glass transition of hydrated wheat gliadin powders with moisture absorp...Modulated-temperature differential scanning calorimetric and dynamic mechanical analyses and dielectric spectroscopy were used to investigate the glass transition of hydrated wheat gliadin powders with moisture absorption ranged from 2.30 db% to 18.21 db%. Glass transition temperature （Tg） of dry wheat gliadin was estimated according to the Gordon- Taylor equation. Structural heterogeneity at high degrees of hydration was revealed in dielectric temperature and frequency spectra. The activation energies （Ea） of the two relaxations were calculated from Arrhenius equation.展开更多
Rheological properties of wheat gliadins in 50% （V/F） aqueous propanol were carried out as a function of gliadin concentration c and temperature. The solutions at 20 g L-1 to 200 g L-1 behave as Newtonian fluids wit...Rheological properties of wheat gliadins in 50% （V/F） aqueous propanol were carried out as a function of gliadin concentration c and temperature. The solutions at 20 g L-1 to 200 g L-1 behave as Newtonian fluids with an flow activation energy of 23.5-27.3 kJ mol-1. Intrinsic viscosity [η] and Huggins constant kH are determined according to Huggins plot at c 〈 120 g L-1. The results reveal that gliadins are not spherical shaped and the molecular size tends to increase with temperature due to improved solvation.展开更多
基金supported by the National Natural Science Foundation of China(Nos.50773068 and 50473039)
文摘Modulated-temperature differential scanning calorimetric and dynamic mechanical analyses and dielectric spectroscopy were used to investigate the glass transition of hydrated wheat gliadin powders with moisture absorption ranged from 2.30 db% to 18.21 db%. Glass transition temperature （Tg） of dry wheat gliadin was estimated according to the Gordon- Taylor equation. Structural heterogeneity at high degrees of hydration was revealed in dielectric temperature and frequency spectra. The activation energies （Ea） of the two relaxations were calculated from Arrhenius equation.
文摘Rheological properties of wheat gliadins in 50% （V/F） aqueous propanol were carried out as a function of gliadin concentration c and temperature. The solutions at 20 g L-1 to 200 g L-1 behave as Newtonian fluids with an flow activation energy of 23.5-27.3 kJ mol-1. Intrinsic viscosity [η] and Huggins constant kH are determined according to Huggins plot at c 〈 120 g L-1. The results reveal that gliadins are not spherical shaped and the molecular size tends to increase with temperature due to improved solvation.
