紫薯花色苷热稳定性研究

Degradation kinetics of anthocyanins in purple sweet potato

为了解紫薯花色苷热稳定性,明确其加工特性,研究了不同加热温度对紫薯花色苷含量的影响以及在不同pH缓冲溶液其含量的变化。结果表明,紫薯花色苷对热不稳定,其花色苷含量随着加热时间的延长呈下降趋势,并且温度越高下降速度越快,热降解符合动力学一级反应。紫薯花色苷在低pH缓冲溶液中热降解活化能高,降解速率低,半衰期长,稳定性好。

In orde to understand the stability of purper sweet potato anthocyanin and clear the application conditions, the effect of various heating temperatures and different pH in buffer solutions on the thermal stability of anthocyanins in purple sweet potato was studied. The results showed that the anthocyanin in purper sweet potato was not stable to heat, the anthocyanin content decreased as the heating time increased, it degraded faster as the heating temperature was higher. The anthocyanin degradation fitted a first-order reaction model. The activation energies（Ea） increased, reaction rate（k） decreased, half life periods（t1/2） increased with decreasing pH.