番茄红素光异构化及热稳定性研究

Study on photoisomerization and thermal stability of lycopene

中文关键词:  番茄红素  光异构化  顺式占比  稳定性

英文关键词:lycopene  photoisomerization  cis proportion  stability

中文摘要:

      目的 优化全反式番茄红素光异构化的工艺条件, 并研究其稳定性。方法 采用光照协同光敏剂的方法对全反式番茄红素进行异构化, 以顺式占比为指标, 通过响应面实验选择最优条件。结果 响应面优化实验结果表明, 番茄红素质量浓度为0.16 mg/mL、荧光素质量浓度为0.14 mg/mL、时间为56 min, 此条件下得到番茄红素顺式占比最高为33.71%。采用高效液相色谱法进行番茄红素结构的测定, 最终得到5种番茄红素异构体, 包括(5,9)-顺式番茄红素、13-顺式番茄红素、番茄红素异构体1、番茄红素异构体2和全反式番茄红素。稳定性实验结果表明, 在不同温度条件下, 各异构体均会发生不同程度的降解, 番茄红素各异构体在37℃条件下的变化最为显著, 而在4℃条件下降解最慢。此外, 全反式番茄红素在几种主要番茄红素同分异构体中表现出最高的稳定性, 其次是(5,9)-顺式番茄红素, 而13-顺式番茄红素的稳定性最低。结论 本研究通过光异构化提高了番茄红素的顺式占比, 并对其热稳定性进行研究, 为开发番茄红素系列产品提供理论依据。

英文摘要:

      Objective To optimize the technological conditions of photoisomerization of all-trans lycopene and study its stability. Methods The method of light synergistic photosensitizer was used to isomerize all-trans lycopene. Taking cis-proportion as an index, the optimal conditions were selected by response surface experiment. Results The results of response surface optimization experiment showed that the mass concentration of lycopene was 0.16 mg/mL, the mass concentration of fluorescein was 0.14 mg/mL, and the time was 56 min. Under this condition, the highest proportion of lycopene was 33.71%. The structure of lycopene was determined by high performance liquid chromatography). Five kinds of lycopene isomers were obtained, including (5,9)-cis-lycopenes, 13-cis-lycopenes, lycopene isomer 1, lycopene isomer 2 and all-trans lycopene. The results of qualitative experiments showed that different isomers of lycopene could be degraded at different temperatures. The changes of lycopene isomers were the most significant at 37℃ and the slowest at 4℃. In addition, all-trans lycopene showed the highest stability among several major lycopene isomers, followed by (5,9)-cis-lycopenes, while (13)-cis-lycopenes had the lowest stability. Conclusion In this study, the cis proportion of lycopene is improved by photoisomerization, and its thermal stability is studied to provide a theoretical basis for the development of lycopene series products.