烘烤过程中不同部位烟叶颜色值和主要化学成分的变化

Color parameters and chemical components in different leaf positions of flue-cured tobacco leaves during bulk curing process

为优化烤烟密集烘烤技术,实现烟叶烘烤进程的精准化和智能化控制,以中烟100下部叶、中部叶和上部叶为试验材料,研究了密集烘烤过程中不同部位烟叶亮度值(L*)、红度值(a*)、黄度值(b*)、彩度值(C*)、色相角(H)与主要化学成分变化的关系。结果表明:密集烘烤过程中3个部位的烟叶各颜色值变化趋势基本一致,开始烘烤至42℃变化最为显著,但上部叶各颜色值变化较中部叶和下部叶滞后;不同部位烟叶颜色值与主要化学成分相关性差异较大,其中总酚含量与各颜色值的相关性均不显著,但还原糖和色素类物质与各颜色值的相关性较好;中部叶还原糖含量与L*值和a*值呈极显著正相关,与b*值和C*值呈显著正相关,与H值呈极显著负相关;下部叶和中部叶叶绿素a含量和叶绿素总量、中部叶叶绿素b含量与b*值和C*值呈显著相关,与a*值和H值呈极显著相关;上部叶叶绿素类物质含量只与a*值和H值极显著相关;下部叶和上部叶类胡萝卜素含量与a*值呈显著负相关,中部叶类胡萝卜素含量则与a*值呈极显著负相关,中部和上部叶的类胡萝卜素含量与H值呈极显著正相关,下部叶的与其呈显著正相关;只有中部叶类胡萝卜素含量与L*值呈显著负相关。

The changes of color parameters including lightness value（L＊）,redness value（a＊）,yellowness value（b＊）,Chroma value（C＊）and Hue Angle（H）,the changes of chemical components and the relationship between color parameters and chemical components in lower,middle and upper leaves of flue-cured tobacco during bulk curing process were investigated to provide theoretical basis for optimizing the curing technology and for controlling the curing process precisely and intelligently.Results showed that,the color parameters in different positions of the flue-cured tobacco showed a consistent changing pattern,from the beginning of the curing process to the time when the temperature reached 42 ℃,the color parameters in the leave changed most remarkably,but the changes of upper leave were slower than that of the middle and lower leaves.The correlations between color parameters and chemical components were quite different among different leaf positions.There was no significant correlation between color parameters and total phenols,but there were good correlations between color parameters and reducing sugar and pigments.Reducing sugar in middle leaves had significant positive correlations with L＊ and a＊,significant positive correlation with b＊ and C＊ and significant negative correlation with H.Chlorophyll-a and chlorophyll in lower and middle leaves and chlorophyll-b in middle leaves were significantly correlated to b＊ and C＊,very significantly correlated to a＊ and H.Chlorophyll in upper leaves had significant correlation with a＊ and H.Carotenoid of lower and upper leaves showed significant negative correlation with a＊,in middle leaves showed very significant negative correlation with a＊,in middle and upper leaves showed significant positive correlation with H,in lower leaves showed significant positive correlation with H,and in middle leaves showed significant negative correlation with L＊.