福建烟叶游离氨基酸等主要含氮化合物与感官质量的关系

  目的  为明确烟叶游离氨基酸等主要含氮化合物与感官质量的关系。  方法  以烤烟品种云烟87为试验材料，测定不同施氮量和留叶数对初烤烟叶各叶位的烟碱、总氮、蛋白质、20种游离氨基酸含量的影响，通过感官质量评价分析主要含氮化合物与感官质量的关系。  结果  1）不同部位烟叶游离氨基酸总量差异显著，依次为下部叶＞上部叶＞中部叶；2）简单相关分析表明，总氮、蛋白质、游离氨基酸总量以及非烟碱氮占总氮含量的比例，与感官质量呈极显著的负相关关系；脯氨酸占游离氨基酸总量的比例，与感官质量呈极显著的正相关关系；3）逐步回归分析表明，在烟碱、蛋白质和20种游离氨基酸中，谷氨酸、谷氨酰胺、丙氨酸对感官质量的负面效应大于烟碱、蛋白质以及其它游离氨基酸。4）在8个处理中，施氮量127.5 kg/hm2、留叶数14片/株处理的烟叶，非烟碱氮、谷氨酸、谷氨酰胺、丙氨酸含量以及游离氨基酸总量最低，感官质量较好。  结论  控制烟叶非烟碱氮含量，尤其是降低谷氨酸、谷氨酰胺、丙氨酸以及游离氨基酸总量，有利于提高烟叶品质。 

Correlation analysis of free amino acid and other major nitrogen compounds and sensory quality of flue-cured tobacco in FuJian

  Background  This study aims to determine the relationship between nitrogen compounds such as free amino acids and sensory quality of tobacco.  Methods  The effects of different nitrogen application rate and number of leaves remained on nicotine, total nitrogen, protein and 20 kinds of free amino acids in leaves of flue-cured tobacco yunyan 87 were determined. The relationship between nitrogen compounds and sensory quality of flue-cured tobacco was analyzed by sensory quality evaluation.  Results  The results showed that: 1) The contents of free amino acids varied significantly with the position of tobacco leaves, which can be ranked in the order as lower leaves > upper leaves > middle leaves. 2) Simple correlation analysis showed that there was an extremely significant negative correlation between sensory qualityandwith total nitrogen, protein, free amino acids and non-nicotine nitrogen/total nitrogen, while there was an extremely significant positive correlation between sensory quality and the proportion of proline to total free amino acid. 3) Stepwise regression analysis showed that glutamic acid, glutamine and alanine had more significant negative effects on sensory quality than nicotine, protein and other free amino acids. 4)The contents of non-nicotinic nitrogen, free amino acid, glutamic acid, glutamine and alanine in tobacco leaves were the lowest under the nitrogen application rate at 127.5kg/hm2 and number of leaves remained at 14 pieces/plant, and the sensory quality was better.  Conclusion  Controlling the content of non-nicotinic nitrogen, especially reducing the nitrogen compounds such as glutamine, glutamic acid, alanine and total free amino acid, can improve the quality of tobacco leaves.