烟叶烘烤过程中呼吸速率和脱水速率的变化

烟叶烘烤过程中，点火开始后一段时间内，呼吸速率有一个明显的下降过程，变黄中后期呈现一个时间长，速率高的呼吸旺盛时期；定色前期呈现第二个时间不长，强度也相对较弱的呼吸旺盛时期，这两个呼吸高峰的演变除因外界条件的影响外，呼吸基质的变化也是主要原因，烤烟调制过程中烟叶脱水速率变黄前期脱水很少，之后逐步增强直至定色中期，这是第一次由弱变强的脱水过程，主要表现为叶肉细胞脱水，定色后期出现第二次强度较大的脱水过程，表现为维管束脱水。

Varation of the Respiratory Rate and Drying Rate During the Flue Curing of Tobacco

During the flue curing of tobacco,the respiratory rate declined obviously at the begginning of firing,then rised to reach the first peak in the later yellowing stage,and reached the second peak in the ealier color fixing stage. The second peak was lower than the first. Besides outside influence, respiratory substrate change was the main reason which developed these two peaks. Drying rate was at lower lever in ealier yellowing stage, then increased gradually to the first peak at mid color fixing stage. This drying stage was caused by mesophyll cell dewatering. The second drying peak was higher than the first in the later color fixing stage, which was caused by the vascular bundle dewatering.