密集烘烤过程中烤烟上部叶质地和色度变化研究

研究上部烟叶叶片、主脉在密集烘烤中质地和色度随干湿球温度变化的规律，为烘烤工艺的优化和完善提供理论依据。分别应用质构仪质地分析试验法和色差计研究了烘烤中烟叶硬度、回复性、粘聚性、咀嚼性4个质地参数和L*、a*、b*三个色度参数及水分的变化情况。结果表明:烘烤中烟叶叶片质地和色度各参数在变黄期38℃前后发生了明显的变化；主脉各参数主要在42℃之后，尤其是48~54℃。烘烤中烟叶TPA(texture profile analysis)测试评价参数硬度、回复性、咀嚼性曲线图的动态变化更为直观。烘烤中烟叶色度各参数差异性均极显著（P<0.01），且a*值差异显著性好于b*值；叶片色度的差异显著性比主脉的更直观。相关分析表明，烘烤中烟叶叶片TPA测试参数硬度、粘聚性、咀嚼性的相关性较好（0.952~0.992），是评价烟叶质地变化的可靠性指标；粘聚性和回复性可以灵敏地反映烟叶主脉的质地变化。相对于主脉，叶片色度的各参数的相关性更好（0.852~0.962），呈显著或极显著正相关。色度各参数的相关分析表明，L*与a*的相关性明显好于L*与b*的相关性。 

Study on texture and color change in upper leaves during bulk flue-curing

Change of texture and color in upper tobacco leaves (not including midrib) and its midrib following dry and wet bulb temperature during bulk-curing were studied in order to provide theoretical basis for optimization and perfection of curing technology. Four texture parameters including hardness, resilience, cohesiveness and chewiness, three color parameters including L*, a*, b* with moisture of tobacco leaves during bulk-curing were studied by texture and color profile analysis with Stable Micro System texture analyzer and colorimeter, respectively. Results showed that texture and color parameters of tobacco leaves changed greatly around 38℃ in yellowing stage during bulk-curing process. Texture and color parameters of midrib of tobacco leaves changed greatly after 42℃, especially at 48~54℃. The dynamic changes of texture parameters curve including hardness, resilience and chewiness of tobacco leaves were intuitive in texture profile analysis test during bulk-curing. Differences of all color parameters of tobacco leaves were highly significant (P<0.01) during bulk-curing and the difference of a* was more significant than b*. At the same time difference of color in tobacco leaves (not including midrib) were more visible than midrib’. Correlation analysis showed that correlation of texture parameters of tobacco leaves including hardness, resilience, and chewiness was better (0.952~0.992) and were reliable index on evaluation of texture profile analysis. Texture of midrib of tobacco leaves was sensitively reflected by cohesiveness and resilience. Compared with midrib, correlation of color parameters of tobacco leaves was better (0.852~0.962) and positively significant or highly significant. Correlation between L* and a* was better than L* with b*’ from correlation analysis of color parameters.