烘烤期间带茎采收的烤烟顶部叶某些生理生化特性变化

为进一步探讨烤烟顶部叶带茎采收烘烤的生理生化机制,对烤烟顶部叶带茎采收烘烤和不带茎采收烘烤的色素含量、淀粉酶、多酚氧化酶(PPO)、超氧化物歧化酶(SOD)、过氧化物酶(POD)活性及丙二醛(MDA)含量进行了测定。结果表明,烤烟顶部叶带茎采收烘烤在变黄12~24h时的叶绿素降解速度快于不带茎采收烘烤,到定色末期时带茎采收烘烤和不带茎采收烘烤的顶部叶叶绿素含量基本相同;带茎采收烘烤与不带茎采收烘烤的顶部叶类胡萝卜素与叶绿素的比值变化趋势基本一致,但带茎采收烘烤比不带茎采收烘烤的类胡萝卜素的降解量大。带茎采收烘烤和不带茎采收烘烤的顶部叶淀粉酶活性变化规律差异较大。带茎采收烘烤的PPO活性总体上低于不带茎采收烘烤,SOD活性高于不带茎采收烘烤,POD活性和MDA含量低于不带茎采收烘烤。综合分析,烤烟顶部叶带茎采收烘烤的生理生化变化对烤后烟叶的质量形成是有利的。

Change of Physiological and Biochemical Characteristics of Flue-cured Tobacco Tips Harvested with Stalk During Curing

In order to further investigate the physiological and biochemical mechanism of flue-cured tobacco tips harvested and cured with stalk, the contents of pigment and malondialdehyde (MDA) and the activities of amylase, polyphenol oxidase (PPO), superoxide dismutase (SOD) and peroxidase (POD) of DJ (Treatmenmt 1, tips harvested and cured with stalk) and WJ (Treatment 2, tips harvested and cured without stalk) were studied. The results indicated that: 1) the degradation of chlorophyll in DJ was faster than that in WJ at earlier yellowing stage (12-24h) while the content of chlorophyll in DJ was basically the same as that in WJ at the end of color-fixing stage; 2) the ratio of carotenoid to chlorophyll in DJ and WJ changed basically with the same trend, however, more carotenoid was degraded in DJ; 3) the change of activity of amylase in DJ was obviously different from that in WJ, the activity of PPO in DJ was lower than that in WJ on the whole, while the activity of SOD in DJ higher than that in WJ; the activity of POD and the content of MDA in DJ were lower than that in WJ. Taking all three results into account, the physiological and biochemical changes in DJ are beneficial to the quality of cured tips.