烤后烟叶类胡萝卜素的稳定性及其影响因素

Stability of Carotenoids in Cured Tobacco Leaves and Influencing Factors Thereof

为了探明烤后烟叶褪色的成因,进行了光照、温度、相对湿度、酸、碱、金属离子和还原剂等影响烤后烟叶中类胡萝卜素稳定性的因素试验。结果表明:烤后烟叶在贮藏过程中光照强度越强,类胡萝卜素越易降解,而室内避光条件下烤后烟叶类胡萝卜素的稳定性较强;低温贮藏有利于减缓类胡萝卜素的降解,而高温贮藏条件下易加快其分解;干燥的环境有利于维持类胡萝卜素的稳定性,而潮湿环境促进了类胡萝卜素的降解;在Cu2+,Fe2+,Fe3+,Zn2+和Al3+存在条件下类胡萝卜素稳定性较差,但在其他金属离子存在条件下则较稳定;还原剂对类胡萝卜素有一定的保护作用。因此,推荐烟叶在低温、避光、干燥、偏碱性或适宜的还原剂处理下贮藏,通过农业生产措施降低烟叶中Cu2+,Fe2+,Fe3+,Zn2+和Al3+等金属离子含量,有助于抑制烤后烟叶类胡萝卜素降解及烟叶褪色。

In order to find out the causes of color fading of cured tobacco leaves, the factors, including light irradiation, temperature, relative humidity, pH, metal ion and reductant on the stability of carotenoids in cured leaves were investigated. The results showed that： 1） The degradation of carotenoids in cured leaves positively correlated to light intensity during storage, it was slower when leaves were stored away from light. 2） Low storage temperature facilitated to the alleviation of carotenoid degradation, while high storage temperature accelerated carotenoid decomposing. 3） Dry environment was beneficial to the stability of carotenoids, while the degradation of carotenoids was accelerated by humid environment. 4） Cu2＋, Fe2＋, Fe3＋, Zn2＋ and Al3＋ undermined the stability of carotenoids, while the other metal ions did not. 5） Reductant had certain protective effects on carotenoids. Therefore, it is suggested to store cured leaves at alow temperature, away from light, dry and alkaline environment, or after reductant treatment. Lower the contents of Cu2＋, F＋2＋, Fe3＋, Zn2. and Al3＋ in tobacco leaves via agricultural cultural practices would be helpful to the inhibition of carotenoid degradation and color fading of tobacco.