Studies On "Air-curing First And Then Curing"Technology Of Upper Flue-cured Tobacco Leaves

Used the flue-cured tobacco varieties Yunyan97upper leaves as experimental material to carry out the "air-curing first and then curing" technology in central Hunan tobacco area, this technology was analyzed on the effect of flue-cured tobacco appearance quality, physical characteristic, chemical component, and the energy costs of curing, economic characters, the main research results were as follows:(1) Water loss and yellow rules of tobacco leaves during the air-curing process studied show that, the use of black shade net cover was better, and the air-curing time should not exceed72hours. Fresh tobacco leaves during the air-curing process, Black shade net cover had some moisturizing effect, the relative humidity was more suitable in the process of air-curing, and in the actual operation convenient than black film and transparent film. Black film and transparent film moisturizing effect better, starch degradation greatly, but because of the relative humidity was too big, tobacco leaf color easy to deepen and brown, would affect the quality of tobacco leaf curing.(2) The air-curing time of tobacco leaves studied show that, first air-curing36hours and then flue-curing into the barn was beneficial to improve the usability of tobacco leaves. Prolonged air-curing time of tobacco leaf can shortened the total curing time, reduced the energy costs of curing, increased the amount of curing barn. The proper air-curing time can increased the proportion of superior tobacco leaves and average price, achieve to the quality and efficiency effect, and also can reduced the consumption of tobacco leaf dry matter and blade thickness shrinkage, increased the balance water proportion, reduced the nicotine content of tobacco leaves, and then can improved the quality of tobacco leaves. However, the content of total sugar, reducing sugar, starch and the two sugar difference was reduced in tobacco leaves along with the increase of air-curing time.(3) The loading density of "Air-curing first and then curing" technology studied show that, the modulation quality performance of barn loading amount of tobacco3500kg was the best. Along with the increase of loading density, appearance quality of flue-cured tobacco leaf increased; Leaf thickness and leaf weight had a descending trend; The content of total sugar and reducing sugar reduced; The content of starch, the content of potassium and two sugar difference increased. Appropriately increasing the loading density could reduced the energy consumption of average cost, and improved the proportion of superior tobacco leaves and average price of flue-cured tobacco leaf; but the amount of tobacco excessively loaded, and vice versa.(4) The "Air-curing first and then curing" modulation technology studied show that, the modulation quality by modulation technology of air-curing24hours, the dry bulb temperature of38℃steady temperature18hours,42℃steady temperature12hours was the best. Along with the increase of air-curing time, shorten yellowing stage time, the appearance quality comprehensive score, single leaf weight, the content of starch, and the content of two sugar difference of flue-cured tobacco leaves showed a gradual downward trend, appearance quality and physical characteristic of flue-cured tobacco leaves were the best performance with the modulation technology of air-curing24hours, the dry bulb temperature of38℃steady temperature18hours,42℃steady temperature12hours.