雪茄烟叶发酵过程中颜色变化与主要含氮化合物及评吸质量的关系

【目的】分析雪茄烟叶发酵过程中颜色变化与主要含氮化合物（总氮、烟碱、蛋白质、氨基酸、硝酸盐、亚硝酸盐、叶绿素a和叶绿素b）及评吸质量的关系，为提升雪茄烟叶发酵品质提供参考依据。【方法】以德雪1号上部叶为试验材料，采用人工堆积法进行发酵，测定发酵过程中雪茄烟叶颜色、主要含氮化合物及评吸质量的变化，探究烟叶颜色变化与主要含氮化合物、评吸质量的关系并建立动态变化预测方程。【结果】雪茄烟叶发酵过程中总氮、烟碱、蛋白质、氨基酸、叶绿素a、叶绿素b含量与颜色参数L*、a*、b*、C值均呈缓慢降低的变化趋势，发酵0~10 d雪茄烟叶含氮化合物降解速率较快，发酵25~30 d差异不显著（P>0.05），发酵30 d时，总氮、蛋白质、烟碱、氨基酸、叶绿素a和叶绿素b含量分别降解18.8%、23.5%、42.5%、31.8%、42.2%和41.4%，L*、a*、b*和C值分别为30.245、8.305、14.350和16.580。硝酸盐、亚硝酸盐含量和H0值呈先升高后降低的变化趋势，△E值呈缓慢上升的变化趋势，发酵30 d时，硝酸盐含量、亚硝酸盐含量、H0和△E值分别为5.78 mg/g、21.11 μg/g、30.060和62.303。发酵25 d时烟叶评吸质量较好，雪茄烟风格彰显，烟叶香气透发，烟气醇和感、饱满度和干净度明显提升，杂气和刺激性明显降低，余味舒适，烟气平衡感较好，各评吸指标均优于未发酵烟叶。相关分析结果表明，发酵过程中雪茄烟叶颜色参数与主要含氮化合物、评吸质量的相关性达显著（P<0.05）或极显著（P<0.01）水平。回归分析结果表明，总氮、蛋白质、氨基酸、叶绿素a和叶绿素b对发酵过程中雪茄烟叶颜色变化有直接影响，评吸质量与颜色参数关系密切。【结论】发酵过程中颜色参数与主要含氮化合物及评吸质量关系密切，通过建立发酵过程中评吸质量变化模型来提高雪茄烟叶发酵过程中的可控性，获得评吸质量较好的雪茄烟叶。

The relationship between the color change of cigar tobacco leaf and the main nitrogen compounds and smoking quality during fermentation

【Objective】To analyze the relationship between the color change and the main nitrogen compounds(total nitrogen, nicotine, protein, amino acid, nitrate, nitrite, chlorophyll a, chlorophyll b) and the quality of smoking during the fermentation process of cigar tobacco leaves, so as to provide a reference for the improvement of the fermentation qualityof cigar tobacco leaves.【Method】Using the upper leaves of Dexue No.1 as the test material, the artificial stacking method was used for fermentation, and the changes in the color, main nitrogen compounds and the quality of smoking cigar tobacco leaves during the fermentation process were measured, and the relationship between these parameters was investigated to establish a dynamic predictive equation.【Result】The contents of total nitrogen, nicotine, protein, amino acid, chlorophyll a, chlorophyll b and color parameters L*, a*, b*, and C values all showed a slow decreasing trend during the fermentation of cigar tobacco leaves. The degradation rate of nitrogen compounds was rapid and there was no significant difference between 25th and 30th days of fermentation (P>0.05). After 30 days of fermentation, the contents of total nitrogen, protein, nicotine, amino acid, chlorophyll a and chlorophyll b were degraded by 18.8%, 23.5%, 42.5%, 31.8%, 42.2% and 41.4%, with L*, a*, b* and C values of 30.245, 8.305, 14.350 and 16.580, respectively. The contents of nitrate, nitrite and H0 showed a trend of first increasing and then decreasing, while the △E value showed a slow increasing trend. At 30th d of fermentation, the nitrate content, nitrite content, H0 and △E values were 5.78 mg/g, 21.11 μg/g, 30.060 and 62.303, respectively. All evaluation indicators of fermented tobacco were better relative to unfermented tobacco leaves. However, when fermented for 25 days, the quality of the tobacco leaves was better than at 30 days; the cigar style was prominent, the aroma of the tobacco leaves was clear, the mellowness, fullness and cleanliness of the smoke were significantly improved, the miscellaneous gas and irritation were significantly reduced, the aftertaste was comfortable and the smoke balance was better. The results of correlation analysis showed that the correlations between the color parameters of cigar tobacco leaves and the main nitrogen compounds and the quality of smoking during the fermentation process were significant(P<0.05) or extremely significant(P<0.01). The results of regression analysis showed that the contents of total nitrogen, protein, amino acid, chlorophyll a and chlorophyll b had a direct impact on the color changes of cigar tobacco leaves during the fermentation process and the evaluation of smoking quality was closely related to the color parameters.【Conclusion】The color parameters in the fermentation process are closely related to the main nitrogen compounds and the quality of smoking. By establishing a model of the quality of smoking during the fermentation process, the controllability of the fermentation process of cigar tobacco leaves is improved and cigar leaves with better quality of smoking are obtained.