增强UV-B辐射对烤烟主要香气前体物及化学成分的影响

摘要

In order to investigate the reasons for the formation of aroma style of quality tobacco leaf and the accumulation of aroma components in flue-cured tobacco, the contents of aroma precursors, including plastid pigments ( chlorophyll, lutein, (5-carotene ) and polyphenols ( chlorogenic acid, rutin ) , and total sugar, reducing sugar, total nitrogen, protein, nicotine, potassium in the upper and middle leaves of flue-cured tobacco exposed to natural light with higher UV-B intensities were determined. The results showed that the synthesis of plastid pigment in upper leaves was suppressed,while that in middle leaves was promoted by intensified UV-B radiation; however,the synthesis of polyphenols was on the contrary. The contents of total sugar, reducing sugar, totalnitrogen, protein and nicotine in upper leaves and total sugar and reducing sugar in middle leaves were decreased, while potassium content in upper leaves and the contents of total nitrogen, protein, nicotine and potassium in middle leaves were increased by intensified UV-B radiation. The main aroma precursors and chemical components in flue-cured tobacco were closely correlated to the intensity of UV-B, proper UV-B intensification would improve the aroma and quality of middle leaves of flue-cured tobacco.%为了探明影响特色优质烟叶香气风格形成和烤烟致香成分积累的原因,通过增强UV-B的方法,测定了光照中紫外线强度增大后烤烟的中上部烟叶质体色素(叶绿素、叶黄素、β-胡萝卜素)和多酚类物质(绿原酸、芸香苷)等香气前体物及总糖、还原糖、总氮、蛋白质、烟碱、钾等化学成分的含量.结果表明,增强UV-B辐射会抑制烤烟上部叶的质体色素合成,促进中部叶质体色素的合成,多酚受UV-B增强的影响表现与质体色素相反；增强UV-B辐射烤烟上部叶总糖、还原糖、总氮、蛋白质、烟碱含量降低,钾含量升高,中部叶总糖、还原糖含量降低,总氮、蛋白质、烟碱、钾含量升高.烤烟的主要香气前体物及化学成分与UV-B强度密切相关,适当增强UV-B有利于烤烟中部叶香气和品质的提高.