烤烟密集烘烤过程中阶梯升温变黄生理生化特性研究

用电热式温湿度自控密集烤烟箱,研究了烤烟密集烘烤过程中阶梯升温变黄生理生化特性。结果表明,阶梯升温变黄处理的淀粉酶活性在变黄期和定色期出现了2次活性高峰,且淀粉酶活性高于对照;多酚氧化酶(PPO)活性在烘烤过程中表现为先降低再升高又降低趋势,且其酶活性比对照变化幅度小,相对较稳定;叶绿素和类胡萝卜素含量下降幅度大于对照,降解较彻底。阶梯升温变黄处理淀粉降解较快,整个烘烤过程中其淀粉含量均低于对照;总糖和还原糖含量积累也较多;总氮和烟碱含量烤后略有升高,与对照差异不大。总的来看,阶梯升温变黄处理的生理生化表现更有利于烤后烟叶品质的提高。

Physiology and Biochemistry Characters of Step Temperature Yellowing during Bulk Curing Process of Tobacco Leaves

The physiology-biochemistry characters of step-temperature yellowing treatment were studied during bulk curing process by using the electric-heated flue-curing barn.The results showed that two obvious amylase activity peaks of step-temperature yellowing treatment appeared in yellowing stage and leaf drying stage,and amylase activity of step-temperature yellowing treatment was higher than 38℃ yellowing treatment.Polyphenol oxidase(PPO) activity of all the treatments decreased before 7-8 tenth yellow,then it displayed the trend with first increasing followed by decreasing after 7-8 tenth yellow for leaves during curing.And polyphenol oxidase activity of step-temperature yellowing treatment had a smaller variation range,and it was more relatively stable.chorophyll and carotinoid content of step-temperature yellowing treatment declined more than 38℃ Yellowing treatment.Starch of step-temperature yellowing treatment had a faster degradation,and its starch content was less than 38℃ Yellowing treatment during curing process.The step-temperature yellowing treatment was beneficial to increase the accumulation of total sugar and reducing sugar.The total nitrogen and nicotine contents of cured leaves of step-temperature yellowing treatment rose slightly,which was similar to 38℃ yellowing treatment.The step-temperature yellowing treatment was beneficial to improving the quality of tobacco leaf by the comprehensive performance of physiology-biochemistry.