烘烤方式对烤烟蛋白酶和淀粉酶活性及化学成分的影响

Effect on Main Enzyme Activity and Chemical Composition of Flue-cured Tobacco by Different Curing Methods

本文研究了常规挂竿、"两炖一停"和散叶装筐3种密集烘烤方式对烘烤过程中云烟87烟叶蛋白酶和淀粉酶活性及化学成分的影响。结果表明:烟叶烘烤过程中两种酶活性变化规律相似,均呈现上升-下降-上升-下降的"双峰曲线",但不同烘烤方式两种酶活性高低存在一定差异,以T2处理("两炖一停")酶活性最高,蛋白酶的峰值分别为258.2 U/mg、263.3 U/mg蛋白,淀粉酶的峰值分别为26.79 U/mg、25.45 U/mg,分别较其他处理高出30.92 U/mg^59.31 U/mg、5.41 U/mg^9.13 U/mg;不同烘烤方式两种酶活性峰值出现的时间也存在一定差异,T2处理蛋白酶和淀粉酶峰值分别出现在42 h、78 h和42 h、84 h,较其他处理晚6 h^12 h;蛋白质和淀粉含量在烘烤变黄期快速下降,但在变黄前期下降速率T3>T1>T2,变黄后期T2>T1>T3,约90 h时达到稳定。烘烤结束后淀粉和蛋白质含量T3>T1>T2。因此,"两炖一停"密集烘烤方式最有利于提高烟叶蛋白酶和淀粉酶活性,最有利于淀粉和蛋白质分解和烟叶化学品质的提高。

Three intensive flue-curing methods of tobacco,i. e. conventional hanging rod,＂two stews and one stop＂and loose leave in box,were investigated on Yunyan87. The results showed that the activities of the two enzymes in the process of roasting were similar,showing a ＂double-peak curve＂of rising,falling,rising and falling. But there were some differences in the activity of the two enzymes in different flue-curing methods. The highest activity was T2 treatment（ ＂two stews and one stop＂）,with the peak of protease at258. 2 U/mg and 263. 3 U/mg,respectively,which were 30. 92-59. 31 U/mg higher than other treatments.The peak of amylase were 26. 79 U/mg and 25. 45 U/mg,respectively,which were 5. 41-9. 13 U/mg higher than other treatments. There were also some differences in the peak time of the two enzymatic activities from other different treatments. The peak of protease appeared at 42 h and 78 h and amylase appeared at 42 h and 84 h,which were 6 h-12 h later than other treatments. The content of protein and starch decreased rapidly during the yellowing to roasting stage,but the rate of decrease was T3 T1 T2 in the early yellowing stage,and T2 T1 T3 in the late yellowing stage,reached a steady state about 90 h. At the end of the roasting,starch and protein content of T2 was the lowest. Therefore, ＂ two stews and stop＂ was the most conducive intensive flue-curing method to improve the enzyme activity and also the most conducive method to the decomposition of starch and protein and the improvement of chemical quality of tobacco leaves.