烘烤条件对烤烟淀粉降解及相关酶活性的影响

Effect of curing condition on starch degradation and related enzyme activity of flue -cured tobacco

以烤烟品种红花大金元和K326的中部叶为材料,研究了烘烤条件对烤烟淀粉酶和淀粉磷酸化酶活性及淀粉降解的影响。结果表明:烘烤过程中,2种酶活性均出现2次高峰,分别处于烘烤的变黄中期和定色前期。淀粉的降解是淀粉酶和淀粉磷酸化酶综合作用的结果。淀粉的降解集中在烘烤的变黄期,进入定色前期淀粉降解缓慢,定色后期至烘烤结束时,淀粉降解甚微。不同烘烤条件相比较,采用低温低湿变黄,慢速升温定色的烘烤条件,烟叶中淀粉降解量、降解速率,淀粉酶和淀粉磷酸化酶活性较高,烤后烟叶淀粉含量较低,水溶性总糖和还原糖含量较高,总体化学成分较为协调。

Effect of curing condition on the activity of amylase and phosphorylase and starch degradation in tobacco leaves were studied by using cutters of flue-cured tobacco cv. HD and K326 as experimental material. The result indicated two peaks of activity of two amylase during flue-curing. The first one was at middle stage of yellowing.The other one was at the beginning of fixing-color stage. Starch degradation was the result of synergism of amylase and starch phosphorylase. Starch degradation in tobacco leaves was concentrated in the period of yellowing, and slowed down in the earlier stage of fixing-color, then was tiny from later stage of fixing-color to the end of flue curing. During the whole process of flue-curing, the quantity and the velocity of starch degradation, the activity of amylase and starch phosphorylase was relatively high in tobacco leaves of lower temperature and humidity yellowing, slow heating speed fixing-color. The content of starch was lower, while the content of soluble sugar and reducing sugar were higher and the whole of chemical component was relatively harmonized in lower temperature and humidity yellowing, slow heating speed fixing-color cured tobacco leaves.