Abstract The objectives of this work were to study the thermal degradation kinetics of l -carnitine and to develop a procedure for thermal inactivation kinetics determination from dynamic temperature profile experiments. Experiments were conducted at isothermal conditions in a temperature range from 80 to 130 °C. Remaining l -carnitine concentration was measured at predescribed time intervals at each temperature tested. The kinetic parameters DTref and z were determined after the first order kinetic behavior of l -carnitine thermal inactivation was verified. Furthermore, l -carnitine concentration data were collected during a non-isothermal experiment and the DTref and z values were determined through appropriate methodology. From the isothermal experiments, the parameters D120°C and z were calculated equal to 50.4 min and 30.8 °C, respectively. Similar values (D120 °C = 52.0 min and z = 31.8 °C) were obtained from the measurements during the dynamic temperature profile experiment. Based on the agreement between the parameters estimated using isothermal and non-isothermal temperature profiles, and given the reduced number of experimental data required by the latter approach, kinetic parameter estimation from experiments at dynamic conditions is recommended.

中文翻译：

---

L-肉碱的热降解动力学

摘要 这项工作的目的是研究左旋肉碱的热降解动力学，并开发一种通过动态温度曲线实验确定热失活动力学的程序。实验在 80 至 130 °C 的温度范围内的等温条件下进行。在每个测试温度下以预先描述的时间间隔测量剩余的左旋肉碱浓度。在验证左旋肉碱热灭活的一级动力学行为后确定动力学参数 DTref 和 z。此外，在非等温实验期间收集了左旋肉碱浓度数据，并且通过适当的方法确定了 DTref 和 z 值。根据等温实验，计算出的参数 D120°C 和 z 分别等于 50.4 分钟和 30.8°C。从动态温度曲线实验期间的测量中获得了类似的值（D120 °C = 52.0 分钟和 z = 31.8 °C）。基于使用等温和非等温温度曲线估计的参数之间的一致性，并考虑到后一种方法所需的实验数据数量减少，建议根据动态条件下的实验估计动力学参数。