不同温度对番茄红素原料和胶束中番茄红素异构体的影响

Effects of different temperatures on lycopene extracts and lycopene isomers in micelles

中文关键词:  温度  番茄红素  稳定性  降解动力学  活化能

英文关键词:temperature  lycopene  stability  degradation kinetics  activation energy

中文摘要:

      目的 分析番茄红素原料和胶束中的番茄红素在不同温度下的构型变化规律。方法 通过高效液相色谱法测定不同温度(4、25、37℃)下番茄红素胶束中番茄红素构型变化情况。结果 各异构体降解速率常数(k)的绝对值会随着温度的升高而变大, 表明其降解速率加快, 结构越不稳定。通过对比显示, 4种番茄红素异构体, 稳定性由高到低依次为: 5-顺式(5 Z)>全反式(All-E)>9-顺式(9 Z)>13-顺式(13 Z)。番茄红素原料中13 Z、9 Z、All-E和5 Z的活化能分别为22.0、23.4、26.5、27.6 kJ/mol, 而番茄红素胶束中13 Z、9 Z、All-E和5 Z的活化能均高于番茄红素原料, 分别为25.8、26.0、31.5、31.9 kJ/mol。结论 将番茄红素包载于聚合物胶束中, 可提高其稳定性, 同时随着温度升高, 番茄红素各异构体稳定性降低。

英文摘要:

      Objective To analyze the conformational change pattern of lycopene in lycopene extracts and micelles at different temperatures. Methods The conformational changes of lycopene in lycopene micelles at different temperatures (4, 25 and 37℃) were determined by high performance liquid chromatography. Results The absolute value of the degradation rate constant (k) of each isomer became larger with increasing temperature, indicating an accelerated degradation rate and a more unstable structure. Comparison showed that the 4 kinds of lycopene isomers, in descending order of stability, were: 5-cis (5 Z)>all-trans (All-E)>9-cis (9 Z)>13-cis (13 Z). The activation energies of 13 Z, 9 Z, All-E and 5 Z in lycopene raw material were 22.0, 23.4, 26.5 and 27.6 kJ/mol, respectively, while the activation energies of 13 Z, 9 Z, All-E and 5 Z in lycopene micelles were all higher than those of lycopene raw material, 25.8, 26.0, 31.5 and 31.9 kJ/mol, respectively. Conclusion Polymeric micelles that contain lycopene slow down its degradation, lycopene isomers become less stable with increasing temperature.