维生素C磷酸酯镁的稳定性及其清除超氧离子自由基的动力学

摘要

维生素C磷酸酯镁(magnesium aseorbyl phosphate,MAP)是维生素C(Vc)的替代品,由于其特有的性质而广泛应用在食品添加剂中.对比测定了MAP和Vc清除超氧阴离子自由基(O2-·)的能力,研究了Vc和MAP在不同温度和不同保存时间后清除O2-·自由基的能力和稳定性；并拟合了不同温度下储存不同时间后MAP的抗氧化能力.结果表明,MAP在20℃下保存20 d对O2-·的清除能力仅减弱20％左右,半衰期为53 d；但Vc在20℃下保存10 d后清除O2-·的能力几乎完全消失.与此同时,不同温度下储存不同时间后MAP清除超氧阴离子自由基的反应为一级反应,采用拟合方程计算的抗氧化能力理论值和实验值基本相符.%Thanks to its peculiar properties, magnesium ascorbyl phosphate (MAP) as a substitute of vitamin C (Vc) is widely used as food additive. This research compares the ability of MAP and Vc to scavenge superoxide anion radical (O2-·). Their ability to scavenge O2- · and their thermal stability were investigated in relation to storage at different temperature for different duration. Furthermore, their anti-oxidation ability was also examined in relation to storage at different temperature for different duration. Results show that the ability of MAP to scavenge O2- · is reduced by only about 20% after it is stored at 20 ℃ for 20 d, and in this case its half-life is 53 d. However, after being stored at 20 ℃ for 10 d, Vc nearly completely loses ability to scavenge O2-·. In the meantime, the reaction for MAP stored at different temperature for different duration to scavenge O2- · can be described with a first order dynamics equation, and its anti oxidation ability calculated based on the simulated equation well conforms to the experimental one.