Study on Loading Leaves Density with Cage Clamp on Quality of Cured Tobaccos in Bulk-Curing Barn

In order to determine the best loading density of tobacco leaf with cage clamp in bulk-curing barns, a curing test was conducted on middle-part tobacco leaves. The results showed that for good appearance quality of cured tobacco, the loading density at 59.52 kg/m2 （4 000 kg/barn） was the best, fol owed by 66.96 kg/m2 （4 500 kg/barn） and 74.40 kg/m2 （5 000 kg/barn）. As leaf loading density increased, the contents of leaf nicotine and total nitrogen increased, sugar content had smal changes, the ratio of sugar to nicotine decreased and tended to be balanced and the content of neutral aroma substances was decreasing, but the difference among treatments was not significant. With the increase of loading density, the sensory quality of cured leaf was better. When leaf loading density was 66.96 kg/m2 （4 500 kg/barn）, apperance quality of cured leaf improved considerably, with prominent aro-ma. Therefore, the best loading density of tobacco leaf in cage clamp of bulk-curing barn would be 66.96 kg/m2 （4 500 kg/barn） .

The Mechanism of Carotenoid Degradation in Flue-Cured Tobacco and Changes in the Related Enzyme Activities at the Leaf-Drying Stage During the Bulk Curing Process

The mechanism of carotenoid degradation and the changes in the activities of related enzymes in flue-cured tobacco at the leaf-drying stage during the bulk-curing process were studied in order to provide theoretical basis for optimization of curing technology. The effect of different rising speeds of temperature on the carotenoid degradation and the related enzymes activities at the color-fixing stage during the bulk curing process was studied by using the electric-heated fluecuring barn designed by Henan Agricultural University, China, based on curing technology with yellowing at low temperature and moderate humidity and leaf drying at moderate humidity. The results showed that the carotenoid degradation components （β-carotene, lutein, neoxanthin, and violaxthin） decreased gradually at the color-fixing stage during the bulk curing process. The carotenoid degradation components viz.,β-carotene, lutein, neoxanthin, and violaxthin at the slow heating curing （T1） were relatively higher than the rapid heating curing （T2） accounting for 10, 2, 32 and 32% respectively, but there were no differences among treatments （P〉 0.05）. The effect of different conditions of curing on the activities of enzymes related to carotenoids degradation were significant. The lipoxygenase, phenylalanine ammonialyase, peroxidase, and polyphenol oxidase enzymes had a bidirectional effect on the quality of tobacco leaves and it was beneficial to form more premise matter of aroma based on the higher enzyme activities at the early leaf-drying stage. The slow heating could regulate the change in various enzymes＇ activities reasonably, making cell redox reaction to reach the dynamic balance and make the degradation of carotenoids adequately. Meanwhile, it could avoid the occurrence of browning reaction and provide foundation for improving the quality of tobacco and optimization of technology for bulk curing and further enhancing aroma.

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.

Study on Curing Effect and the Waste Heat Recovering Equipment Design of Flue Gas of Bulk Curing Barn

In order to realize tobacco curing with energy saving and emission reduc- ing and lower cost, the waste heat recovering equipment was designed and built on blowing-upward type bulk curing barn. The comparative experiment of tobacco leaf curing was conducted between a bulk curing barn with waste heat of flue gas and conventional bulk curing barn. The results showed that the effect of saving coal in bulk curing barn with waste heat of flue gas was obvious than the contrast. The coal consumption quantity was 1.531 kg per kg of dry tobacco leaf. The saving coal in bulk curing barn with use waste heat of flue gas was 0.181 kg per kg of dry tobacco leaf than the contrast and saving coal rate was 10.57%. The electricity consumption quantity was 0.593 kWh per kg of dry tobacco leaf. The saving elec- tricity quantity in bulk curing barn with use waste heat of flue gas was 0.022 kWh/kg and the saving electricity rate was 3.58% than the contrast. The saving curing cost was 0.158 yuan per kg of dry tobacco leaf and saving cost rate 9.09% in bulk cur- ing barn with use waste heat of flue gas than the contrast. The appearance quality, grade structure and primary chemical composition had no significant difference be- tween bulk curing barn with use waste heat of flue gas and the contrast.

Analysis of Sulfur Dioxide Concentration Around Bulk Curing Barn Group

This study was conducted to analyze the spatial distribution of SO2 mass concentration around baking barn groups. A bulk curing barn group was selected as monitoring object, and SO2 concentration around it was monitored for 2 years. The results showed that the SO2 mass concentration within 30-130 m from the baking barn group exceeded the standard, and with the ground as reference, the SO2 mass concentration at the position 0.9-2.1 m from the ground exceeded the stan- dard. According to the limit value of the SO2 mass concentration for sensitive crops, the SO2 mass concentrations over the standard were concentrated within the range of 200-300 m. On the basis of establishment of ＂sulfur control＂, ＂sulfur reduction＂ and ＂sulfur avoiding＂ system, the SO2 emission status of baking barn groups could be improved from the conversion of heat supply method, the utilization of clean en- ergy and adjustment of crop sensitive period and sensitive area.

Doing a Good Job in Inspection and Maintenance of Facilities and Equipments in Bulk Curing Barn

Due to the limited management funds and insufficient management efforts,curing barns in traditional tobacco area are outdated and equipments are seriously damaged,which affects the normal operation and increases the maintenance cost of bulk curing barns,bringing adverse effects on tobacco leaf curing in the coming year and the sustainable development of tobacco industry in the future.To ensure the normal operation of curing barns and effectively prolong the service life of curing barns during tobacco leaf curing,we should do a good job in the publicity of management and maintenance,improve the system of management and maintenance,raise funds for management and maintenance,inspect facilities and equipments,carefully maintain equipments in curing barn and strictly perform examination and inspection.

箱式烘烤对烤后烟叶品质的影响

[目的]深入探讨箱式烘烤方式下烤烟综合品质特征,加快箱式烘烤技术在烤烟生产中的推广应用。[方法]以潍坊烟区NC55烟叶为试验材料,开展了箱式烘烤与传统挂竿烘烤对比试验,从外观质量、物理特性、常规成分、感官质量和化学成分多个维度系统分析了箱式烘烤下烟叶品质特性。[结果]与挂竿烘烤相比,箱式烘烤烟叶外观质量、物理特性和感官质量接近或高于挂竿烘烤;箱式烘烤中部烟叶总糖、还原糖、淀粉、糖碱比显著高于挂竿烘烤,总氮和氮碱比显著低于挂竿烘烤,上部烟叶中仅淀粉箱式烘烤显著高于挂杆烘烤;箱式烘烤糖醇类香气前体物含量显著高于挂竿烘烤,中部烟叶大部分香气前体物和香气物质含量箱式烘烤低于挂竿烘烤,上部烟叶中差异相对较小。[结论]箱式烘烤2个部位烟叶品质大都较挂竿烘烤有不同程度的提升,可在实际生产中推广应用。

改良热泵密集烤房烘烤工艺及其效果分析

为进一步利用热泵密集烤房优势,解决热泵密集烤房与现有工艺不匹配、初烤烟叶化学成分提升不明显等问题,对传统三段式烘烤工艺进行改良,对初烤烟叶的主要化学成分、石油醚提取物、多酚类物质、香气代谢产物及评吸质量进行分析。结果表明:与传统三段式烘烤工艺相比,可变频密集烤房采用改良三段式烘烤工艺后效果较好,其初烤烟叶化学成分赋值提高8.9%,淀粉含量下降20.0%,中性致香物质含量提高0.7%,多酚类物质含量提高49.4%,评吸得分提高6.2%。说明改良三段式烘烤工艺可促进烟叶香气代谢产物的积累和化学质量、评吸质量的提高。综合分析,改良后的三段式烘烤工艺能够有效提升热泵密集烤房初烤烟叶质量,有较好的实用价值。

变容积密集烤房的CFD分析与试验研究

为保障密集烤房装烟密度,降低烘烤的能源消耗,研发一套适用于密集烤房的变容积系统。在完成变容积装置的设计后,基于CFD方法模拟分析装置与烟叶的不同距离对烤房内部气体分布均匀性的影响。通过烘烤试验获取实际烘烤数据,对模拟值加以验证。试验结果表明:当隔板与烟叶距离为0 cm时,流速不均匀系数Kv为0.40,温度不均匀系数Kt为0.41,距离为10 cm时,Kv=0.41,Kt=0.43;距离为20 cm时,Kv=0.42,Kt=0.49。装烟区9个测量点的温度模拟值与实测值基本吻合,误差在6%以内。变容积烤房在装烟量为一半时,相比常规烤房的燃料消耗可节约13.4%。研究结果表明:当隔板与烟叶距离为0 cm时烤房内部的气体分布最均匀;CFD模型与数值模拟结果具有可靠性;变容积装置具有较好的保温效果,可保证装烟密度,降低烤烟能耗。

不同新能源类型密集烤房烘烤效果研究

通过烘烤试验对比,从烤房建造成本、运行参数、烘烤能耗用工、控温精度、烤后烟叶外观质量、化学成分、经济效益等方面探索内置式生物质烤房、密闭式热泵烤房、光伏一体化烤房的烘烤效果,旨在筛选曲靖烟区最适宜的烤房类型,并为烟草行业的绿色可持续发展提供理论依据。结果表明,密闭式热泵烤房烘烤能耗和用工成本较低,控温精度、烤后烟叶质量、经济效益较好,是目前最适宜曲靖烟区的烤房类型;光伏一体化烤房建造成本高昂,且烘烤效果表现一般,目前推广难度较大,但可作为未来烤房的发展方向;内置式生物质烤房建设使用门槛较低,可在生物质颗粒供方市场成熟和电力配套设施不齐全的烟区加以应用。

密集烤房排湿余热回收系统性能研究

针对密集烤房开式排湿造成的能源浪费问题,设计了一种利用重力热管的排湿余热回收系统。通过烘烤试验研究,得到了排湿气流的状态参数和燃料消耗量。结果表明,密集烤房排湿余热回收系统的平均显热效率为36.61%,平均全热效率为15.97%;与对照烤房相比,每公斤干烟可节约燃料0.22kg,节能率达到9.11%,该系统具有良好的工程应用价值。

碳基有机肥对烤烟生长及产质量的影响

本研究以烤烟品种云烟87为试验对象,设置不同碳基有机肥施用量,研究其对烤烟生长及产质量的影响。结果表明:施用碳基有机肥可以提高烟叶产量,改善农艺性状及品质,烤后烟叶均符合优质烟叶指标要求;与常规施肥对照相比,烟叶总产量提升52.3%~96.6%,优质烟叶产量提升44.5%~54.0%,中等质量烟叶产量提升68.7%~144.0%。综合来看,以施用碳基有机肥1500 kg/hm^(2)对烤烟生长及产质量的提升效果最好。

可变频热泵密集烤房烟叶烘烤性能及效益分析

为解决传统密集烤房存在的问题,为变频热泵密集烤房在烟叶烘烤上的应用提供参考,设置加装变频风机的空气能热泵烤房、普通空气能热泵烤房、加装变频风机的传统燃煤密集型烤房和普通传统燃煤密集烤房4种处理,对不同类型烤房的烘烤性能与烟叶烘烤效益进行比较分析。结果表明:可变频热泵密集烤房烘烤的烟叶内在化学成分比例较好,淀粉含量显著低于其他3组处理;各处理中以可变频热泵密集烤房成本最低(887.96元/房),且烤后烟叶感官质量及评吸结果显著优于其他处理。综合分析,可变频热泵密集烤房在烟叶烘烤实用性上具有突出优势,能够有效提高烟叶烘烤质量和收益。

滇南丘陵烟区2种烘烤工艺应用效果对比研究

为进一步优化滇南丘陵某烟叶主产区烘烤工艺,采用对比烘烤试验,分析该烟区密集烤房常用的“三段十点烘烤工艺”(工艺A)和“三段六步烘烤工艺”(工艺B)2种烘烤工艺烤后烟叶的经济性状、烤坏烟数量及比例。结果表明:同等条件下工艺B能够明显减少挂灰烟、黑糟烟和级外烟数量,烘烤损失更低;对于上部烟叶,工艺B较工艺A烤后烟叶的均价提高0.5元·kg^(-1),增效较为明显。工艺A受普通烤房烘烤和三层密集烤房的烘烤技术影响较大,变黄期以“低温保湿变黄”策略为主,低温变黄时间偏长、排湿较少(小),整个烘烤过程设置的温度点较多,变黄期和定色期各相邻阶段的干球温度差异、目标任务差异相对较小,对操作人员判定烟叶变化是否达到目标、准确把握转火时机有较高技术要求,操控难度相对偏大。工艺B特点是高温变黄、低温定色、边变黄边排湿,慢升温,针对四层密集烤房上下层温差偏大的实际,干球38℃以前的低温变黄时间较短,以38℃为顶层烟叶主变黄温度,以42℃为底层烟叶主变黄温度,同时在42℃阶段提高了烟叶失水程度(顶层勾尖卷边、底层凋萎塌架),相对更有利于避免定色前期棕色化反应的发生。综上,相较于“三段十点烘烤工艺”(工艺A),“三段六步烘烤工艺”(工艺B)更加适用于滇南丘陵某烟叶主产区鲜烟叶烘烤特性、四层密集烤房性能特点,但要结合当年气候和鲜烟叶素质差异灵活操作。

密集烘烤38℃和46℃不同稳温时间对豫中上六片烟叶品质的影响

为进一步提高豫中上六片烟叶烤后质量,以中烟100上部烟叶为供试材料,研究变黄及定色阶段稳温时间对烤后烟叶品质的影响。结果表明,与常规烘烤工艺相比,变黄阶段38℃延长12 h,可提高上等烟占比和均价,改善外观油分、结构、色度、嗅香等及化学成分协调性,并改善感官评吸香气量、杂气、余味、燃烧性等指标,大幅增加中性致香物质总量;定色阶段46℃延长12 h,可提高上等烟占比和均价,改善外观结构、色度、嗅香等及化学成分协调性,明显增加中性致香物质总量,但不利于感官质量改善,香气质、香气量等指标略有下降;变黄阶段38℃和定色阶段46℃均延长12 h,可明显提高上等烟占比和均价,改善化学成分协调性,改善感官评吸香气质、香气量、杂气、余味、燃烧性等指标,大幅增加中性致香物质总量。综上,38℃延长12 h处理及38℃、46℃均延长12 h处理,其烤后烟叶整体表现较好,以38℃、46℃均延长12 h效果最好。

密集烘烤定色前期升温速度阈值与挂灰烟成因分析

为改善密集烤房烟叶烘烤工艺,提升烤后烟叶的综合品质,以云烟97为试验材料,通过密集烤房研究烘烤定色前期不同升温速度对烤后烟叶含青程度、挂灰程度、经济性状、化学品质性状的影响。结果表明:适当延长定色前期升温时间,即升温速度在2~3 h/℃时,烤后烟叶外观质量显著改善,上等烟和中上等烟产出率显著提高,化学成分趋于协调,香气量增加,抽吸品质提高。

基于积温积湿与聚类分析的密集烤房温湿度时空分布特征研究

为了明确密集烤房烟叶烘烤过程中的温湿度时空分布规律,提高烟叶烘烤效果,本研究采用密集烤房温湿度自动精准监测系统获取不同部位烟叶烘烤过程中烤房的环境参数,进行聚类分析和精准分类。结果表明,不同部位烟叶烘烤时,密集烤房内温湿度时空分布规律有一定差异。根据不同区域积温、积湿等情况,在下部叶、中部叶和上部叶烘烤过程中,可分别将密集烤房装烟室划分为3类、3类和4类区域,不同素质的鲜烟叶可与相应的区域进行精准匹配。

大块充填树脂固化深度及聚合转化率的比较研究

目的比较3种大块充填树脂与2种传统复合树脂之间的固化深度、聚合转化率差异,为临床上选择适宜的树脂充填材料提供参考。方法选用大块充填树脂X-tra fill、SureFil SDR、Filtek bulk fill、传统膏状树脂Filtek Z250XT及传统流动树脂Filtek Z350XT共5种光固化充填树脂,每种树脂在1000 mW/cm^(2)的光强度下进行固化,各制备5个试件。根据ISO 4049:2019标准测量树脂的固化深度,通过傅里叶变换红外光谱法检测树脂的聚合转化率。结果与传统复合树脂相比,大块充填树脂的固化深度、聚合转化率均显著提高(P<0.01),其中大块充填树脂X-tra fill、SureFil SDR的聚合转化率优于Filtek bulk fill。结论大块充填树脂的固化深度、聚合转化率高于传统树脂,光固化反应更充分,在临床中更适合用于深窝洞的充填,并提高工作效率。

衡阳烟区上部烟叶不同装烟方式烘烤效益比较

[目的]探索适合衡阳本地上部烟叶的最佳烘烤方式。[方法]以云烟87为试验材料,对比分析常规挂杆烘烤、梳式烟夹烘烤、带茎烘烤3种密集烤房装烟方式对上部烟叶烘烤成本、烘烤效益及烤后质量的影响。[结果]与常规挂杆装烟方式相比,烘烤成本烟夹装烟方式有所下降,带茎烘烤反而增加;烤后质量方面,烟夹烘烤与挂杆烘烤基本持平,带茎烘烤提升明显,内在化学成分协调性最优;综合效益烟夹烘烤与带茎烘烤均有所提高,以带茎烘烤最优。[结论]带茎烘烤有利于提高衡阳烟区烤烟上部烟叶的质量,改善上部烟叶的可用性,提高烟农收益,具有较大的推广价值。

不同成熟度烟叶烘烤中颜色值和色素含量的变化

【目的】了解不同成熟度烟叶密集烘烤中颜色值和色素含量的变化以及它们之间的关系,为密集烘烤工艺的优化和完善提供理论依据。【方法】采用全自动测色色差计,对比研究烘烤中未熟、尚熟、适熟和过熟烟叶颜色参数(L*、a*、b*)和色差参数(△L*、△a*、△b*)的变化特征,采用分光光度法测定不同成熟度烟叶叶绿素、类胡萝卜素含量等指标。【结果】不同成熟度烟叶的L*、a*值在烘烤过程中均呈现升高的趋势,b*值在48℃之前升高,48—54℃有所下降,之后稍有回升。L*的变化规律表现为过熟>适熟>尚熟>未熟,鲜烟叶a*值在不同成熟度之间差别不大,在变黄中期之前成熟度高的烟叶a*值上升较快,烤后烟叶b*值大小表现为尚熟>未熟>过熟>适熟。随着烘烤的进行,烟叶△L*总体趋势变小。在48℃烟叶△a*明显变大,△b*相对降低,尤其以未熟和过熟烟叶明显。相关分析表明,尚熟和适熟烟叶的类胡萝卜素含量与L*值均呈极显著负相关(r=-0.979,-0.851,P<0.01),类胡萝卜素含量与a*值呈显著负相关(r=-0.832,-0.853,P<0.05)。烘烤过程中适熟烟叶的L*、a*和b*与各种色素含量的回归方程分别为y1=245.67 x1+114.75 x2-211.69 x3-125.21 x4+118.69,y2=416.9 x1+369.19 x2-404.38 x3-78.38 x4+43.55,y3=-1051.55 x1-1270.02 x2+1106.42 x3+17.48 x4+40.1。【结论】烘烤中不同成熟度烟叶正反面颜色变化趋势基本同步,烟叶颜色参数和色素含量的相关性明显,可以用颜色值作为辅助指标来判断烟叶成熟度。