密集烘烤关键温度点稳温时间对烟叶颜色和色素降解的影响

为优化密集烘烤工艺，提升烟叶质量特色，对密集烘烤关键温度点不同稳温时间的烟叶颜色参数和质体色素变化进行了研究。结果表明，烘烤过程变黄期关键温度点时间延长，烟叶亮度值、黄度值和叶片饱和度增加；随着定色期关键温度点时间的延长，亮度值降低，但对烟叶黄度值和叶片饱和度影响较小；红度值则随着各关键温度点稳温时间的延长而增加，主脉红度值只有在延长54℃稳温时间时能明显提高；色度角随着稳温时间的延长而降低，烟叶颜色偏向橘黄；在42℃和54℃延长时间有利于降低烟叶正背面色差值；叶绿素和类胡萝卜素随着烘烤时间的延长降解转化更彻底。因此，密集烘烤关键温度点延长稳温时间，在38℃稳温24 h，42℃稳温16 h，47℃稳温20 h，54℃稳温16 h，烟叶内质体色素降解更充分，烤后烟叶颜色和色度增强。

Effects of Ti me of Constant Te mperatures of Key Te mperatures on Color and Pig ment of Tobacco Leaves in Bulk Curing

In order to optimize the bulk curing technology and improve the quality of tobacco leaves,the changes of color parameters and pigment of tobacco leaves were studied with optimum time of constant temperatures of key temperatures of bulk curing combination.The results showed that,with prolonging the of constant temperatures of yellowing stage key temperatures,values of brightness （L）and yellow （b）of tobacco leaves and saturation of leaves without vein presented increasing trends and yellowing temperature advanced.And the values of brightness （L）decreased and there were little influence on yellow values （b）of leaves and saturation of leaves without vein,with prolonging the of constant temperatures of leaf-drying stage key temperatures.With prolonging the of constant temperatures of key temperatures of bulk curing,the red values （a）of tobacco leaves without vein showed increasing trends and chroma angle （H°）of tobacco leaves which turned croci.But the red values of principal vein improved obviously by only prolong the stable times of 54℃.And prolonging the of constant temperatures of key temperature especially 42℃and 54℃would be beneficial to reducing color difference between the front and back of tobacco leaves.Chlorophyll and carotenoid would degrade and transform completely.So prolonging the of constant temperatures of key temperatures during bulk curing,38℃24 h,42℃ 16h,47℃20 h and 54℃16 h,chromoplast pigment would degrade completely and color and chroma of flue-cured tobacco leaves would enhance.