密集烘烤过程中不同前处理烟叶生理生化变化研究

研究烟叶密集烘烤前进行的不同处理对烟叶在烘烤过程中主要生理生化变化规律的影响,试验设鲜烟叶烟梗划开(T1)、鲜烟叶背面烟梗剔除(T2)和常规烟叶烘烤(CK)3个不同处理,利用河南农业大学设计的电热式温湿自控密集烤烟箱对烟叶进行烘烤。结果表明:在烘烤过程中,各个处理中水分、叶绿素、类胡萝卜素和淀粉等含量及超氧化物歧化酶活性、过氧化物酶活性均呈现不同程度的下降趋势,丙二醛含量、苯丙氨酸裂解酶活性呈上升趋势,脂氧合酶活性则先上升后下降,而淀粉酶活性呈现双峰曲线。T2处理烟叶中的水分、类胡萝卜素、丙二醛、淀粉酶活性等含量和脂氧合酶活性均高于T1处理,而其叶绿素含量、淀粉含量、超氧化物歧化酶活性、过氧化物酶活性均低于T1处理。T2处理的烟叶在外观质量、化学成分协调性和感官质量方面均优于T1处理。T2处理能够很好地调控烟叶中水分和各种酶活性的变化,使细胞氧化还原反应达到一种动态平衡,使叶绿素和淀粉充分降解,又能避免酶促棕色化反应的发生,能进一步改善烟叶品质和优化密集烤房增香工艺。

Study on physiological and biochemical changes in flue-cured tobacco leaves of different pretreatments in bulk curing

The authors focus their study on the influence of pretreatments with tobacco leaf before curing on main physiological and biochemical changes during curing.The test had three different treatments including gashing fresh tobacco cabo(T1);eliminating the cabo on the back of tobacco leaf(T2),and having conventional tobacco baking(T3).The flue-curing was taken by using the electric-heated flue-curing barn designed and made by Henan Agricultural University.The results indicated that during the curing process,each treatment showed that moisture,chlorophyll,carotenoid and amylum contents and activities of superoxide dismutase and peroxidasein in the tobacco leaves all went down with different degrees,while the malondialdehyde content and the activities of phenylalanine lyase tended to raise,and lipoxygenase activity increased first and then decreased,and the amylase activity in the curing process showed a double-peak curve change.Compared the test result of T1 with T2,as for the result of T2,the moisture,carotenoid and malondialdehyde contents and activities of amylase and lipoxygenase in the tobacco leaves were higher than in the result of T1 in the curing way of tobacco stem being incised,while in T2,the chlorophyll and amylum contents and activities of superoxide dismutase and peroxidase in the middle leaves of tobacco in tobacco stem being culled were lower than that in T1.It can be found that the appearance quality,chemistry composition and sensory quality of the flue-cured tobacco in T2 were better than that of T1.Furthermore,for the result of T2,tobacco stem being culled in the curing way can be good to regulate the moisture content and changes in enzyme activities,to make cell redox reactions to achieve a dynamic equilibrium,to have the full degradation of chlorophyll and starch and to avoid the occurrence of enzymatic browning reaction,so it can further improve tobacco quality and optimization of aroma-enhancing technique in the curing barn.