Department of Chemical Engineering, Nagoya University, Nagoya 464-8603, Japan.
Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8603, Japan.
Food Chem. 2018 Jun 1;250:253-258. doi: 10.1016/j.foodchem.2018.01.062. Epub 2018 Jan 8.
The stability of lycopene with high Z-isomers content during thermal treatment and light irradiation was investigated. Purified (all-E)-lycopene was thermally isomerized to the Z-isomers in dichloromethane (CHCl) at 50 °C for 24 h. The total content of the Z-isomers of lycopene reached 56.1%. Then, the mixture of lycopene isomers was stored in the dark at 4, 25, and 40 °C for 30 days, and under light irradiation using a fluorescent light at 4 °C for 336 h. The degradation rate of lycopene during thermal treatment rose with increasing temperature and the activation energy for decomposition of the mixture of lycopene isomers was calculated to be 71.0 kJ mol. The degradation rate of lycopene isomers was almost the same under thermal treatment. On the other hand, during light irradiation, isomerization was promoted rather than decomposition, i.e. (9Z)- and (13Z)-lycopene converted to the (all-E)-isomer.
研究了高 Z 异构体含量的番茄红素在热处理和光照下的稳定性。在 50°C 的二氯甲烷（CHCl）中，将纯化的（全 E）-番茄红素热异构化为 Z 异构体，24 小时后，番茄红素的 Z 异构体总含量达到 56.1%。然后，将番茄红素异构体的混合物在黑暗中于 4、25 和 40°C 下储存 30 天，并在 4°C 的荧光灯下光照 336 小时。热处理过程中番茄红素的降解速率随温度的升高而升高，计算出混合物中番茄红素异构体的分解活化能为 71.0kJ/mol。在热处理下，番茄红素异构体的降解速率几乎相同。另一方面，在光照下，异构化得到促进而不是分解，即（9Z）-和（13Z）-番茄红素转化为（全 E）-异构体。
