白肋烟、晒烟和烤烟烟叶在6年贮藏过程中主要酮类香气成分的变化趋势

为了进一步明确不同类型烟叶样品长期贮藏过程中主要酮类香气成分变化规律，采用LC-GC方法测定调制后样品在6年自然贮藏过程中主要酮类香气成分含量。结果表明:1）随贮藏时间增加，烟叶主要酮类香气成分变化均符合二次曲线模型，白肋烟酮类香气物质总量最高，贮藏期间所有阶段平均值为46.251μg/g，且在长期贮藏过程中含量增加时间长，酮类挥发性香气含量峰值出现在61个月。其次为晒烟，贮藏期间平均含量为40.053μg/g，酮类挥发性香气含量峰值出现在48个月。烤烟贮藏期间平均含量最低，为26.306μg/g，酮类挥发性香气含量峰值出现在38个月。2）类胡萝卜素降解产物巨豆三烯酮、氧化紫罗兰酮等含量先上升后下降，呈现抛物线形式。茄酮、降茄二酮等含量逐渐下降。3）白肋烟巨豆三烯酮等含量最高；晒烟β-紫罗兰酮(0.830μg/g)等含量最高；烤烟降茄二酮等含量较高，两地区烤烟降茄二酮平均含量达到0.400μg/g。不同类型烟叶样品适宜的陈化期不同，白肋烟和晒烟比烤烟更耐贮藏，烤烟贮藏时间应控制在35个月内，白肋烟晒烟贮藏时间不超过60个月，有利于提高烟叶可用性。 

Changes of main ketone aroma components in burley,sun-cured and flue-cured tobaccos during 6 years in storage

Changes in main ketone aroma components in different types of tobacco leaves during long time storage were investigated.HPLC-GC/MS was applied to measure content of main ketones during natural storage for 6 years.Results showed that: 1) With the increase of storage time, the changes in main ketone aroma components in samples conformed to quadratic curve model.Total content of ketone aroma compounds in burley tobacco was the highest, with average value of 46.251μg/g during storage, and it increased for a longer time during 6 years storage with the peak value appeared at the 61 months.Sun-cured tobacco was the next place with the average total ketones content being 40.053μg/g during storage, and the peak value appeared at the 48 months.The average total ketones content of flue-cured tobacco was the lowest, only 26.306μg/g, with the peak value appeared at the 38 months.2) Contents of carotenoid degradation products such as megastigmatrienone, oxo-ionone increased first and then decreased, showing a parabolic model.The contents of solanone and norsolandione decreased gradually.3)Burley tobacco and sun-cured tobacco had the highest content of megastigmatrienone and β- ionone (0.830μg/g).Norsolandione contents of flue-cured tobacco samples were relatively high with average value reached 0.400μg/g.According to the research, the appropriate aging time was different for different tobacco types; burley tobacco and sun-cured tobacco were more durable to storage than flue-cured tobacco.Therefore, the storage time of flue-cured tobacco should controlled within 35 months, and the storage time of burley tobacco and sun-cured tobacco could extend to 60 months, for the benefit of improving usability of tobacco leaves.