3-O-乙基维生素C热稳定性及抗氧化性的研究

Study of thermal stability & antioxidative activity of 3-O-ethyl-L-ascorbic acid

采用高效液相色谱法跟踪测定,评价3-O-乙基维生素C的热稳定性。通过清除有机自由基1,1-二苯基苦基苯肼(DPPH)法,评价3-O-乙基维生素C的抗氧化性能。结果表明:在水溶液中60℃保持6周后,3-O-乙基维生素C的保存率为95.5%,维生素C磷酸酯镁保存率为70.6%,维生素C保存率<0.01%。维生素C、3-O-乙基维生素C、维生素C磷酸酯镁去除自由基DPPH的IC50值分别为8.42μg、10.35μg、163.44μg,维生素C、3-O-乙基维生素C、维生素C磷酸酯镁对自由基DPPH的实际清除量分别为2.82 g·g-1、2.29 g·g-1、0.15 g·g-1。

The thermal stability of 3 -O -ethyl -L- ascorbic acid was evaluated by HPLC. The antioxidative activity of 3 - O - ethyl - L - ascorbic acid was evaluated by use of a stable radical 1, 1 - diphenyl - 2 - picrylhydrazyl （DPPH）. Results showed that after 6 weeks at 60℃, the retaining rate of 3 - O - ethyl - L - ascorbic acid, magnesium L - ascorbyl - 2 - phosphate and vitamin C in aqueous solution is 95.5%, 70. 6%, 〈 0.01% respectively. The IC50 （reducing 50% the initial DPPH concentration） of Vitamin C, 3 - O - ethyl - L - ascorbic acid and magnesium L - ascorbyl - 2 - phosphate is 8.42 μg, 10. 35 μg and 163.44 μg respectively, and the radical scavenging amount of Vitamin C, 3 - O - ethyl -L - ascorbic acid and magnesium L - ascorbyl - 2 - phosphate is 2. 82g·g^-1, 2. 29 g·g^-1 and 0. 15g·g^-1 respectively.