Effects of Different Flue-curing Barns on Aroma Quality of Upper Flue-cured Tobacco Leaves of K326

[Objective] This study was conducted to compare the aroma quality of up-per leaves of K326 flue-cured in different barns, and provide theoretical references for the development and optimization of bulk curing barn and the supporting tech-niques. [Method] The upper leaves of K326 were flue-cured in a commonness barn, a four-shelf bulk curing barn and a three-shelf bulk curing barn separately, and then the contents of aroma components and taste quality indices of the finished leaves were measured and compared. [Result] The contents of total aroma components, chromoplast pigment degradation products, phenylalanine aroma components and neophytadiene showed no significant differences in the leaves flue-cured in four-shelf bulk curing barn and commonness barn, but were significantly or very significantly higher than those in the leaves flue-cured in three-shelf bulk curing barn. The con-tents of carotenoid degradation products, Mail ard reaction products, cembranes aro-ma components and total aroma components （except neophytadiene） showed no significant difference among the three treatments. The results of sensory evaluation revealed that the sensory taste of the leaves flue-cured in four-shelf bulk curing barn was the best, as the finished leaves had rich, delicate aroma, comfortable and clean aftertaste. The leaves flue-cured in commonness barn was better than those flue-cured in three-shelf bulk curing barn in aroma quality, amount and aftertaste. [Conclusion] The four-shelf bulk curing barn had a large volume for tobacco leaf processing, but a similar baking environment to the commonness barn, which is conducive to the formation and accumulation of aroma components, so the finished leaves had similar appearance and quality with those flue-cured in commonness barn. The upper flue-cured leaves in three-shelf bulk curing bran had poorer quality than those flue-cured in the other two barns.

Feasibility analysis of using biomass gas or hydrogenin the tobacco curing system

To address the energy shortage and meet the requirements of environmental protection policies,the feasibility of premixed fuel 1(natural gas(NG),syngas,and hydrogen)and premixed fuel 2(NG and hydrogen)in the tobacco curing system was studied.First,according to the law of conservation of energy and mass,a tobacco leaf curing system model was established.Then,the interchangeability index of the premixed fuels was analyzed,and their volume ratios were obtained.Finally,a numerical simulation analysis of the premixed fuel combustion was conducted based on the indicators of emission,temperature,and economy.On this basis,the comprehensive performance indexes of the system composed of different premixed fuels were evaluated.The results obtained indicate that with the increase in the hydrogen volume ratio in premixed fuel 1,NO_(X) emissions will gradually increase.Moreover,with the increase in the hydrogen volume ratio in premixed fuel 2,CO emissions will gradually decrease.Because premixed fuel 2 contains more hydrogen than premixed fuel 1,CO emissions are reduced by 9.39%and 16.72%as compared with the NG system when the volume ratio of NG to hydrogen is 95∶5 and 90∶10,but the NO emissions of the latter are beyond the acceptable range.Finally,the overall performance is good when the volume ratio of NG to hydrogen is 95∶5,and the volume ratio of NG to syngas to hydrogen is 90∶5∶5.

A Preliminary Study on Intensive Curing with Alcohol-based Fuels

The research investigated application effects of alcohol-based fuels in in- tensive curing. The results showed that alcohol-based fuels allow flexible adjustment of temperature and heat supplying. What＇s more, in treatment A, the cured tobac- cos are softer and brighter, with more oil content and higher proportion of first-class tobaccos. Per leaf weight increased by 0.13 g and output value per kang （a heat- able brick bed） deducting energy cost grew by 188.66 yuan. In addition, the con- tents of reducing sugar and potassium enhanced within the ranges of high-quality tobacco, and chemical components are more coordinated.

Yield and Nicotine Content of Flue-Cured Tobacco as Affected by Soil Nitrogen Mineralization

Nitrogen(N)supply is the most important factor affecting yield and quality of flue-cured tobacco(FCT).A field experiment and an in situ incubation method were used to study the effects of soil N mineralization in the later stages of growth on yield and nicotine content of FCT in Fenggang and Jinsha,Guizhou Province.The yield and market value of FCT at Fenggang were much lower than those at Jinsha.However,the nicotine content of middle and upper leaves was much higher at Fenggang than at Jinsha when the same rate of fertilizer N was applied,which might be due to a higher N supply capacity at the Fenggang site.At later stages of growth(7-16 weeks after transplanting),the soil net N mineralization at Fenggang(56 kg N ha^(-1))was almost double that at Jinsha(30 kg N ha^(-1)).While soil NH_4-N and NO_3-N were almost exhausted by the plants or leached 5 weeks after transplanting,the N taken up at the later growth stages at Fenggang were mainly derived from soil N mineralization,which contributed to a high nicotine content in the upper leaves.The order of soil N contribution to N buildup in different leaves was:upper leaves>middle leaves>lower leaves.Thus,soil N mineralization at late growth stages was an important factor affecting N accumulation and therefore the nicotine content in the upper leaves.

Screening of Low Tar Flue Cured Tobacco Varieties

The main agronomic traits,economic traits,appearance quality,main chemical components,gas composition and physical parameters of 10 flue cured tobacco varieties were investigated in the experiment.And the field natural incidence of the main diseases was investigated.The results showed that main agronomic characters of the 10 varieties were in line with the breeding objectives,among which 5 varieties have good economic characters;5 varieties have good appearance quality;6 varieties have coordinated chemical composition and high potassium content;9 varieties have good smoke components and physical indicators.