烟碱向降烟碱转化对烟叶麦斯明和TSNA含量的影响

以白肋烟TN90为材料,研究了非转化株、低转化株及高转化株烟叶样品的烟碱转化程度及降烟碱含量与烟叶麦斯明和烟草特有亚硝胺(TSNA)含量的关系。结果表明,随着烟株烟碱转化能力的提高和烟叶降烟碱含量的增加,叶片和主脉的麦斯明含量呈线性增加。当烟碱转化率超过20％时,麦斯明含量超过了假木贼碱的含量。在4种主要的TSNA中,具有不同烟碱转化能力的样品间4-(甲基亚硝胺基)-1-(3-吡啶基)-1-丁酮(NNK)、N-亚硝基新烟草碱(NAT)和N-亚硝基假木贼碱(NAB)含量没有显著差异,N-亚硝基降烟碱(NNN)含量则随着烟碱转化能力的提高和降烟碱含量的增加而大幅度升高,尤其在主脉中表现更为明显。NNN占总TSNA的比例随烟碱转化程度的提高而增加,在高转化烟株中可高达90％,其它3种TSNA占总TSNA的比例相应降低。叶片中NAT含量和比例一般高于NNK,而在主脉中NNK含量高于NAT。

Effect of Nicotine to Nornicotine Conversion on Myosmine and TSNA Contents in Burley Tobacco

The relationship between nicotine to nornicotine conversion, as well as nornicotine content, and the con-tents of myosmine and TSNA was investigated using burley TN90 samples of no-converter, low and high converter plants. The results showed that myosmine content increased linearly both in lamina and in midrib as nicotine conversion level and nornicotine content increased. When nicotine conversion rate was over 20 % , myosmine content sur-passed anabasine content. Of the 4 main tobacco-specific nitrosamines, NNK, NAT and NAB contents didn' t showsignificant difference among tobacco samples of different conversion levels; while NNN content increased sharply asthe nicotine conversion level raised, especially in midrib, the proportion of NNN in total TSNA increased while theothers decreased accordingly. In high converter plants, the NNN proportion may reach 90 % of the total TSNA. In lamina, the content and proportion of NAT were higher than that of NNK, while in midrib, NNK was higher than NAT in content.