烟叶变黄过程中淀粉与多酚类物质及相关酶活性的变化

Changes of Starch,Polyphenols Content and Related Enzyme Activity of Tobacco Leaves during Yellowing

为了解烟叶在调制过程中的物质变化规律，采用自然堆制变黄方法研究了烟叶在变黄过程中淀粉与多酚类物质及相关酶活性的变化。结果表明，烟叶淀粉含量在开始变黄时高达35％。40％，在变黄过程中随变黄时间快速下降．至变黄后72h其含量已降低了50％。烟叶淀粉酶活性则随变黄时间逐渐增强，至变黄后72h其活性已比开始变黄时增强了1倍多。烟叶淀粉酶活性与烟叶淀粉含量呈线性关系，且下部和中部烟叶二者呈显著（P〈0．05）负相关。上部烟叶二者呈极显著（P〈0．01）负相关。烟叶绿原酸和芸香苷含量随变黄时间变化呈波浪式增加趋势．但增加的幅度较小．而烟叶莨菪亭含量随变黄时间变化无明显规律。烟叶中多酚氧化酶活性随变黄时间的变化呈平缓波动．变化幅度较小。多酚氧化酶活性与烟叶绿原酸、芸香苷和莨菪亭含量之间无线性相关关系．

In order to investigate the rule of material transformation in the curing process of tobacco, changes of starch, polyphenols and related enzyme activities of tobacco leaves were studied under natural yellowing conditions. The results showed that the starch content of tobacco leaves was up to 35%-40% when yellowing, and decreased quickly with yellowing time, and decreased by half after 72 h. Amylase activity of tobacco leaves enhanced gradually with yellowing time, and en- hanced by one times after 72 h. There was a linear relationship between amylase activity and starch content of tobacco leaves, and the linear relationship was significant （P〈0.05） in the lower and middle leaves and very significant （P〈0.01） in upper leaves. The chlorogenic acid and rutin content of tobacco leaves had an increased trend with yellowing time, but the increased rate was smaller. The scopoletin content of tobacco leaves had no significant change with yellowing time. The polyphenol oxidase activity of tobacco leaves changed small with yellowing, but had a gentle fluctuations. There was no linear correlation between the polyphenol oxidase activity and chlorogenic acid content, and rutin content, and scopoletin content.