Research On The Key Technology Of Improving Quality Of Flue-cured Tobacco With Bulking Curing Barn

In this study, bulk curing barn of Xiangmi-Ⅰ as baking processing equipment, K326 as research material. The component and content of the harvesting standard of tobacco at different position, the time being delayed at 38℃ in yellowing stage and fan speed being adjustabled by frequency were analyzed and researched in the tobacco-growing areas of Longhui in Shaoyang City.The main results are as follows:1 Cleared the maturity standard of tobacco at different position.Lower leaves, about the 70d after transplanting,leavescolor has turned yellow-green, the tobacco area of 80%has changed to yellow, above 1/2 mid rid has turned white, tobacco pubescence small amount shedding. The cured leaf appearance quality could be increased, the balanced chemical was components, the proportion for middle-grade and first-grade leaves were increased, sense organ quality constituents and total aroma were the highest.Middle leaves, about the 95d after transplanting, Leavescolor has turned light yellow, with above2/3 mid rid in white, tobacco pubescence more shedding. The cured leaf appearance quality could be increased, the balanced chemical was components, the proportion for middle-grade and first-grade leaves were increased, sense organ quality constituents and total aroma were the highest.Upper leaves, about the 125d after transplanting, the percent of leaf area Of 90～100% has changed to yellow, and mid rid has turned white, tobacco pubescence a large amount shedding. The cured leaves appearance quality could be increased, the balanced chemical were components, the proportion for middle-grade and first-grade leaves were increased, sense organ quality constituents and total aroma were the highest.2 The leavse could be turned depth yellow and promote post-ripening by delaying at 38℃ in yellowing stage.Lower leaves prolonging curing time for 8 hours, middle leaf prolonging curing time for 24 hours, upper leaves prolonging curing time for 32 hours at 38℃ in yellow stage, that were the best for the quality of flue-cured tobacco. For example, the tissue structure has beenloose, the oil has been rich, the proportion of orange tobacco leaves was higher, starch and the content of total sugar accumulation were decreased, the balanced chemical was components, the content of aroma constituents of middle and upper leaves respectively was improved by 14.17% and 18.64%, smoking quality was better.3 Frequency motor of bulk curing could automatic controlled the fan speed, improved the level of automation controlled.The fan speed conditions were preliminarily defined in different curing stage on the capacity of 4800 kg. during yellow stage controling 864-1152 r/min of rotation speed, during color-fixing stag controlling 1440-1152 r/min of rotation speed, during stem-drying stage controlling 1152-864 r/min of rotation speed could satisfy the requirements of baking; cured tobacco orange tobacco and oil content were increased, structure got more loosen, the balanced chemical was components, aroma constituents were increased, smoking quality was better.4 Optimization technology could improve the overall quality of tobacco leaves.The tobacco appearance quality was improved. the tissue structure has beenloose, the proportion of orange tobacco leaves was higher, especially upper leaves quality could be significantly improved, and could decrease starch content and the content of sugar accumulation, a total of 14 kinds aroma constituents was increased, the chemical composition of tobacco leaf was coordination, the quality and aroma of flue-cured tobacco, the aroma matter content was rich and aroma temperament was improved.In general, the tobacco leaves were harvested,while 80 percent of leaf area of lower leaves has changed to yellow, the area of middle and upper leaves’ area of 90% has turned yellow; the leavse could be turned depth yellowby Lower leaves prolonging curing time for 8 hours, middle leaf prolonging curing time for 24 hours, upper leaves prolonging curing time for 32 hours at 38℃ in yellowing stage; the fan speed was adjusted by frequency motor during yellow stage controling 960-1440 r/min of rotation speed, during color-fixing stag controlling 1440-1152 r/min of rotation speed, during stem-drying stage controlling 1152-960 r/min of rotation speed; those technology combined into the new optimization technology to improvet the overall quality oftobacco.