不同基因型烤烟质体色素降解及与烤后烟叶挥发性降解物含量关系

Degradation of Plastid Pigment and Its Relationship with Volatile Catabolite Content in Cured Leaves of Different Genotypes of Flue-Cured Tobacco

【目的】研究不同基因型烤烟成熟和调制过程中色素降解及与烤后烟叶中性挥发性色素降解成分含量的关系。【方法】采用液相色谱方法测定豫中浓香型烟区9个不同基因型烤烟中部叶质体色素含量。【结果】在成熟和调制过程中烟叶的质体色素含量呈下降趋势,叶绿素的总降解量总体大于类胡萝卜素,且叶绿素a的降解量显著大于叶绿素b,在调制后烟叶中叶绿素b残留量较多,叶绿素在烟叶成熟期的降解量大于在调制期间的降解量。在类胡萝卜素中叶黄素含量和降解量最大,且在成熟期间的降解量大于调制期间的降解量,新黄质在成熟期的降解量大于调制期间的降解量,但β-胡萝卜素和紫黄质在调制期间的降解量大于成熟期间的降解量。不同基因型色素降解量不同,且与调制后烟叶色素降解类中性香气成分含量多呈显著正相关关系,与调制后烟叶色素含量无显著相关性或呈负相关关系。类胡萝卜素降解产物总量和许多重要香气成分与成熟期色素降解量的相关性大于与调制期降解量的相关性。【结论】烟叶成熟过程中叶绿素、叶黄素和新黄质的降解量大于调制期的降解量。烤后烟叶中挥发性色素降解香气成分含量与质体色素的降解量,特别是成熟期色素降解量有密切关系,提高烟叶成熟度对促进烟叶香气物质形成至关重要。

[Objective] The research was conducted to investigate the changes in plastid pigment contents during middle leaf mature and curing, and the relationship of pigment degradation amount and rate to volatile pigment catabolite content in cured leaves. [Method] HPLC method was used to measure the pigment and volatile aroma components in 9 genotypes of flue-cured tobacco grown in central I-Ienan Province. [Result] The results showed that the plastid pigment contents decreased during leaf maturing and curing, with the total degradation amount and rate of chlorophyll being greater than that of carotenoids, and that of chlorophyll a being significantly greater than that of chlorophyll b, resulting in relatively higher amount of residue of chlorophyll b in cured leaves. The degradation rate of chlorophyll during leaf maturing was greater than that during curing. Among the carotenoids, lutein had the highest content and greatest degradation amount, and that during leaf maturing was greater than that during curing. The degradation rate of neoxanthin during maturing was also greater that during curing, while it was the contrary for ^-carotene and violaxanthin.Different genotypes had different pigment degradation amounts and had significantly positive correlations with the contents of volatile degraded aroma compounds in cured leaves, while there was no or negative correlations with the contents of pigment residue in cured leaves. Total amount of pigment-degraded aroma compounds and the contents of most important individual aroma components had greater positive correlations with degradation amount during maturing than that during curing. [Conclusion] The degradation amount of chlorophyll, luten and neoxanthin were greater than that during curing. Total amount of pigment degraded aroma compounds had a close relationship with the pigment degradation amount, especially that during maturing. Thus the increase of maturity of tobacco was pivotal in promoting the formation of aroma components in tobacco leaves.