Abstract: In order to fully grasp the changes of nitrogen metabolites during the drying process of cigar tobacco leaves, to formulate a reasonable modulation process, the cigar tobacco variety ‘Gu-5’ was used as material to study the effects of different air-drying densities (40, 60 and 80 pieces·rod^-1) on the changes of the main nitrogen compounds in cigar tobacco leaves. The results showed that, under different air-drying densities, the changing trends of various nitrogen-containing compounds in tobacco leaves were basically consistent. Among them, the change of total nitrogen content showed a “bimodal curve”, and the total nitrogen content was the lowest at the end of air-drying; soluble protein degradation mainly occurred during the wilting phase and the yellowing phase, and the accumulation of amino acids proceeded with protein degradation simultaneously, showing a "fast-slow-fast" variation trend; the total alkaloid content  decreased slightly; nitrate did not change much between before and after air-drying. Among different air-drying densities, total nitrogen, protein and alkaloids of tobacco leaves were degraded the fastest under the treatment of 40 pieces·rod^-1, and the three chemical components  all reached the lowest value at 25 d after air-drying; amino acids content was fully accumulated during air-drying process and eventually reached 7.61 mg·g^-1; its nitrate content was always the lowest during the whole air-drying process. Taken together, the drying density of 40 pieces·rod^-1 was more conducive to improving the quality and industrial availability of cigar tobacco leaves.

Key words: cigar, air-drying, drying density, nitrogen compounds

摘要： 为全面把握雪茄烟叶晾制过程中氮代谢产物的变化规律，以制定合理的调制工艺，以雪茄烟品种‘Gu-5’为试验材料，研究不同晾制密度（40、60和80 片·杆^-1）对雪茄烟叶主要含氮化合物变化规律的影响。结果表明，在各晾制密度下，烟叶各类含氮化合物变化趋势较为一致。其中，总氮含量变化呈“双峰曲线”，晾制结束时含量最低；可溶性蛋白降解主要发生在萎焉期和变黄期，氨基酸积累与蛋白质降解同时进行，呈“快-慢-快”的变化规律；总生物碱含量小幅度降低；硝酸盐含量在晾制前后变化不大。不同晾制密度相比，40片·杆^-1处理下烟叶总氮、蛋白质和生物碱降解最快，3种化学成分均在晾制第25 d达到最低值；同时，该处理烟叶中氨基酸在晾制过程中得以充分积累，最终达到7.61 mg·g^-1；此外，其硝酸盐含量则始终最低。综合来看，40 片·杆^-1的晾制密度更有利于改善雪茄烟叶的品质和工业可用性。

关键词: 雪茄烟, 晾制, 晾制密度, 含氮化合物