Effects of Different Baking Processes on Carotenoid Content in Upper Leaves of Fluecured Tobacco

[Objective] We aimed to improve the quality of flue-cured tobacco with K326 upper leaves and explore the optimal tobacco baking process in Chongqing tobacco-producing region. [Method] Four different baking processes （endogenetic force moisture-removing flue-curing technique, exogenetic force moisture-removing flue-curing technique, three-stage flue-curing process, three-stage and six-step flue- curing process） were adopted in this research to investigate the effects of different baking processes on carotenoid content of same-maturity degree upper leaves of the flue-cured tobacco K326. [Result] The results showed at the yellowing and color fixing stages, the carotenoids were most fully decomposed in endogenetic force moisture-removing flue-curing technique. The decomposed carotenoid content was lowest in exogenetic force moisture-removing flue-curing technique, for which the carotenoid content was highest （50.53 mg/g）. [Conclusion] At the yellowing and color fixing stages, exogenetic force moisture-removing flue-curing technique was most conducive to the carotenoid accumulation in tobacco baking process.

Effects of Exogenous Amylases and Metal Ions on the Amylase Specific Activities and Starch Degradation of the Upper Leaves of ‘KRK_(26)' during Flue-curing

Objective] The aim of this study was to investigate the effects of exoge-nous amylases and Ca2＋, Mn2＋ and K＋ on the amylase specific activities and starch degradation of the upper leaves of ＇KRK26＇ planted in Yunnan Province during flue-curing. [Method] The amylase specific activities and starch degradation of the leaves were determined by using spectrophotometry. [Result] The 8 U/g exogenous α-amy-lase could improve the specific activity of the leaf α-amylase at yel owing and color-fixing stages, but could not at stem-drying stage, and similarly, the 80 U/g exoge-nous β-amylase could improved the specific activity of the leaf β-amylase at the yel owing stage and the early period of color-fixing stage. The leaf starch could be enhanced to degrade by the exogenous α- or β-amylases and the enhancing effect of the former was stronger than that of the later. 1.50 mg/ml Ca2＋ improved the specific activity of the leaf （α＋β）-amylase mainly due to its enhancing effect on the leaf α-amylase, and increased the starch degradation. 4 mmol/L Mn2＋ inhibited the leaf α-amylase from yel owing to the early period of color-fixing and the β- and （α＋β）-amylases from the yel owing to the later period of color-fixing, but enhanced the leafα-amylase from the later period of color-fixing to the later period of stem-drying and the β- and （α＋β）-amylases at the later period of stem-drying. Meanwhile, Mn2＋ ham-pered the starch degradation during yel owing, but promoted it from the early period of color-fixing to stem-drying. 1 mg/ml K＋ enhanced the leaf α-, β- and （α＋β）-amy-lases during the yel owing stage, but lowered them from the early period of color-fix-ing to the later period of stem-drying, and always inhibited the leaf starch degrada-tion. [Conclusion] The exogenous α-, β- amylases and Ca2＋ of suitable concentra-tions could be used to treat the tobacco leaves before flue-curing to improve the leaf starch degradation during the curing.

Judgment of Aroma Types of Middle and Upper Flue-cured Tobacco Leaves Based on Stepwise Discriminant Analysis

[Objective] The aim of this study was to establish mathematical models for judging the aroma types of middle and upper flue-cured tobacco leaves according to the contents and proportions of aroma compositions. [Method] The aroma types of tobacco leaves were judged based on stepwise discriminant analysis, using 63 C3F and 65 B2F tobacco leaf samples from 13 tobacco producing regions in 11 provinces of China （Huili in Sichuan, Baokang in Hubei, Wulong in Chongqing, Lu- oyang in Henan, Zhucheng in Shandong, Wuyi Mountain in Fujian, Malong in Yun- nan, Chuxiong in Yunnan, Bijie in Guizhou, Liuyang in Hunan, Suiyang in Guizhou, Kaiyuan in Liaoning, Nanxiong in Guangdong） as calibration samples, and 67 aroma components as indices. And the Fisher discriminant functions were verified using 21 C3F and 19 B2F tobacco leaf samples. [Result] Variation coefficients of the propor- tions were lower than that of contents of most aroma components in middle and upper leaves of the samples, indicating that the proportions were more stable than contents of aroma components. The proportions of benzyl alcohol, solanone, β-dam- ascone, neophytadiene, farnesylacetone A, palmitic acid, thunbergol, methyl linole- nate and cembratriene-diol were all over 1% in both middle and upper leaves, al- though the dominant aroma components of the same aroma type varied between middle and upper leaves. Moreover, 11, 18, 7 and 11 aroma components were re- spectively introduced into the Fisher discriminant functions established based on the contents and proportions of middle and upper flue-cured tobacco leaves, which ex- hibited accuracy rates of 91.7%, 100%, 91.7% and 91.7% in the judgments of other tobacco leaf samples. The results revealed that the components those determined aroma types in middle leaves were obviously more than in upper leaves. In middle leaves, the accuracy rates of aroma type judgment could be improved by using the proportions rather than the contents of aroma components as indices. However, the functions based on the proportions and the contents of aroma components in upper leaves gave close accuracy rates. [Conclusion] The results of the study will provide references for identifying aroma types of flue-cured tobacco leaves in future work.

Judgment of Aroma Types of Middle and Upper Flue-cured Tobacco Leaves Based on Proportions of Aroma Components

[Objective] This study aimed to establish mathematical models for judging the aroma types of flue-cured tobacco leaves from the upper and middle parts of plants. [Method] A total of 128 samples （63 C3F and 65 B2F） from 11 main tobac- co production provinces of China were selected as materials. Stepwise discriminant analysis was applied to samples with different aroma types and discriminant function was expressed with the proportions of 67 aroma components in total aroma con- stituents as the index. [Result] The ratio of most aroma components in clear and full aroma tobacco leaves was higher than that in middle aroma leaves. The ratios of 51, 43 and 40 aroma components of clear, middle and full aroma tobaccos were higher in upper leaves than that in middle leaves. Aroma components dominated certain aroma types differed between middle and upper leaves. The proportions of 18 and 11 aroma components in upper and middle leaves were led in the stepwise discriminant function respectively. Self-validation and cross-validation methods were applied to evaluate the original samples, and the accuracy rates reached 100% and 98.6% on middle leaves, 96.37% and 94.4% on upper leaves. The accuracy rates on some other samples reached 100% on middle leaves and 91.7% on upper leaves predicted with the model. [Conclusion] The ratio of aroma components as discriminant index could improve discriminant accuracy significantly in the middle and upper leaves. It could be used to analyze aroma types objectively, accurately and quickly.

Differences of Physiological and Biochemical Indexes of Upper Fresh Leaves and Post-growth Roots in Different Quality Stages

In order to explore the physiological and biochemical characteristics of fresh upper leaves and roots of different qualities of tobacco, the malonaldehyde （MDA）, superoxide dismutase （SOD） activity, chlorophyllase activity, amylase activity, medium trace element content, chemical component content, root fresh weight, dry weight and activity in the normal tobacco leaves, tobacco leaves rich in nutrients and premature grey tobacco leaves were studied. The results showed that compared with the normal tobacco leaves, the root fresh weight, dry weight and activity in the premature grey tobacco leaves decreased by 41.22%, 14.44% and 60.29% respectively, while malonaldehyde content increased by 34.82%, and chlorophyllase, α-amylase, β-amylase and SOD activity declined by 89.55%, 65.71%, 71.26% and 37.25% respectively. Chlorophyllase, co-amylase and 13-amylase activity in the tobacco leaves rich in nutrients decreased by 58.76%, 36.19% and 41.93% respectively. The content of medium trace elements in the tobacco leaves rich in nutrients and premature grey tobacco leaves was lower than that of the normal tobacco leaves. Starch, total sugar, reducing sugar and potassium content in the normal tobacco leaves were higher than that of the tobacco leaves rich in nutrients and premature grey tobacco leaves.

主成分分析法在山东上部烟质量评价中的应用

本研究旨在运用主成分分析法对山东地区上部烟叶的质量进行综合评价,以便为该地区烤烟质量的准确评估提供科学依据。研究以山东10个主要植烟县2020年和2021年间105份B2F等级烟叶样品为材料,通过应用标准化法和主成分分析法对这些烟叶样品的物理特性和化学成分指标进行归类处理,并对各植烟县样品的上部烟叶质量进行分类。研究发现,单叶重与叶长和叶宽、叶片密度与叶片厚度、总糖与还原糖、烟碱与氮间极显著正相关,且主成分特征向量一致,可分别归为一类指标。根据物理特性评价结果,可将山东产区上部烟分为三类,根据化学成分评价结果,可将山东产区上部烟分为两类。综合考虑物理特性和化学成分评价结果,山东产区上部烟叶可分为四类。其中沂源、五莲、临朐为一类,兰陵、沂水、莒县、莱芜为一类,淄川、黄岛为一类,诸城则单独构成一类。

蒸汽处理对上部白肋烟重要香味物质的影响研究

【目的】考察蒸汽处理对上部白肋烟重要香味物质的影响。【方法】利用动态水分吸附脱附仪,在95%相对湿度下,研究蒸汽处理温度和处理时长对上部白肋烟非酶棕色化反应产物、苯丙氨酸类降解产物、类胡萝卜素降解产物和西柏烷类降解产物含量的影响,分析这4类重要香味物质在不同处理条件下的变化趋势。【结果】在实验范围内,提高处理温度或增加处理时长会使非酶棕色化反应、类胡萝卜素降解、西柏烷类降解三类产物的含量先增加后减少,而苯丙氨酸类降解产物的含量则呈下降趋势。在60℃处理3h时,上部白肋烟这4类重要香味物质的总含量增加了12.53%,且香气和杂气等感官品质指标明显提高。【结论】蒸汽处理可作为一种有效调控上部白肋烟香味物质和感官品质的方法。

施氮量对云烟121上部烟叶代谢及品质的影响

为提高烤烟上部叶品质与可用性,筛选出曲靖烟区云烟121适宜的施氮量,分别施用纯氮82.5、105.0和127.5 kg·hm^(-2)进行大田试验,测定不同处理的农艺性状、上部成熟鲜烟叶的超微结构及烘烤后的外观质量、化学成分、感官质量等指标,并进行代谢组学分析,综合评价不同施氮量处理下云烟121的生长情况与上部烟叶品质。结果表明,3个施氮量处理烟株的长势无明显差异,其中105.0 kg·hm^(-2)处理烟株的综合发病率最低。随着施氮量的增加,云烟121上部叶片中的叶绿体降解减缓,淀粉粒与嗜锇颗粒体积增大,其中105.0 kg·hm^(-2)处理烟叶的嗜锇颗粒数量最多。施氮水平影响云烟121上部叶的代谢模式,且主要集中在莽草酸和苯丙烷代谢途径。在105.0 kg·hm^(-2)处理下,云烟121上部叶烤后的外观质量、化学成分、感官质量、经济性状均优于其他施氮水平。由此表明,施用纯氮105.0 kg·hm^(-2)能够有效提高曲靖烟区云烟121上部叶的品质与可用性。

上部烟叶在热泵密集烤房稳温降湿烘烤工艺下的物质动态变化

为了探析热泵密集烤房稳温降湿烘烤工艺对上部烟叶物质动态变化的影响,以云烟87上部烟叶为试验材料,对稳温降湿和四步式烘烤工艺下烟叶中的水分、色素、淀粉和还原糖含量的动态变化及其相似性进行比较分析。结果表明:与四步式烘烤工艺相比,在黄片前期稳温降湿烘烤工艺处理烟叶的含水率更高,更有利于叶绿素a、叶绿素b和类胡萝卜素的降解。稳温降湿烘烤工艺处理烟叶的叶绿素a、叶绿素b和类胡萝卜素含量分别较四步式烘烤工艺低7.51%、38.19%、9.53%,但烟叶的淀粉、还原糖含量差异不明显。不同物质在2种烘烤工艺处理下的动态变化相似性表现为水分>叶绿素a>淀粉>叶绿素b>还原糖>类胡萝卜素。烘烤过程中物质动态变化差异可以分为3类,第Ⅰ类包括水分、叶绿素a、叶绿素b、淀粉,2种烘烤工艺的差异主要发生在变黄期;第Ⅱ类为类胡萝卜素,整个烘烤过程,2种烘烤工艺均存在较大差异;第Ⅲ类为还原糖,2种烘烤工艺的差异主要表现在定色期和干筋期。综合分析,采用稳温降湿烘烤工艺有利于上部烟叶色素的降解。

不同润叶和复烤强度对上部烟叶质量的影响

以云烟87上部烟叶为研究对象,以颜色深浅度、色度、均匀度、油分、常规化学成分和感官质量为评价指标,开展了不同润叶和复烤强度对上部烟叶质量的影响研究。结果表明,随着润叶强度的增加,润叶后烟叶颜色逐渐加深,色度偏向深橘黄,均匀度逐渐变差,油分增加;复烤后烟叶颜色变浅,色度向柠檬黄转变,均匀度提升,油分降低,较高温度复烤的烟叶均匀度和油分优于低温复烤;随润叶强度增加烟叶烟碱和总糖含量逐渐升高,复烤后其含量逐渐下降;随润叶强度增加润叶后的感官质量逐渐降低,低水分润叶下随复烤温度增加感官质量提升,高水分润叶下随复烤温度增加感官质量下降。综合来看,低水分润叶(W15%)和较高温度复烤(T 70℃)更有利于上部烟叶质量的形成。

不同氯化钾施用措施对烤烟上部叶产质量的影响

[目的]探讨适宜泸州烟区的氯化钾施用措施,进一步完善田间上部烟叶的调控技术。[方法]采用田间试验,以“中川208”为试材,设施氯量30、60、90、0 kg/hm^(2)4个水平,基追比为5∶5,追施时期设移栽后30和50 d,共7个氯化钾施用处理。分析上部烟叶农艺性状、SPAD值、经济性状、化学成分、物理性状的变化。[结果]较不施用氯化钾而言,施用氯化钾使上部烟叶产量、产值、均价、中上等烟比例分别提高3.11%~9.17%、6.12%~19.29%、2.79%~12.92%、4.01%~18.25%;烤后烟叶颜色、成熟度、身份、油分、色度均得到提升,综合得分提升1.15%~8.30%。[结论]以基肥施用氯化钾30 kg/hm^(2),移栽50 d后追施30 kg/hm^(2)的施肥措施经济效益最高,烤后上部烟叶外观质量、化学成分、物理性状评分最高。

基于代谢组学与蛋白组学的广东烟区沙泥田烤烟上部叶挂灰成因分析

【目的】基于代谢组学和蛋白组学联合分析广东烟区沙泥田与紫色土烤烟上部叶物质代谢和蛋白表达差异,为减少沙泥田烟叶挂灰提供参考依据。【方法】以烤后不易挂灰的紫色土烟叶(对照)和烤后易挂灰的沙泥田烟叶为研究对象,选择2种土壤类型烟叶上部叶欠熟、尚熟、成熟和过熟4个时期的鲜烟叶样品,测定多酚氧化酶(PPO)活性;再以成熟时期烟叶进行代谢组学和蛋白组学联合分析,鉴定沙泥田上部成熟烟叶中的差异代谢物和差异表达蛋白,并分析筛选影响沙泥田上部烟叶褐变的关键通路。【结果】上部叶成熟过程中,紫色土烟叶PPO活性极显著低于沙泥田烟叶(P<0.01),且二者在成熟时期差值最大。从2种土壤类型成熟时期烟叶样品中共筛选出差异代谢物129个,差异表达蛋白1314个,差异代谢物、差异表达蛋白均以上调为主;差异代谢物的聚类和KEGG代谢通路分析主要富集到酪氨酸代谢、苯丙氨酸—酪氨酸—色氨酸生物合成、苯丙素生物合成等通路上。差异表达蛋白的GO功能注释和KEGG信号通路富集分析主要富集到苯丙素生物合成、酪氨酸代谢、异喹啉生物碱生物合成和植物激素信号传导等过程。多酚类物质生物合成过程中,沙泥田烟叶差异表达蛋白苯丙氨酸解氨酶、4-香豆酸辅酶A连接酶、羟基肉桂酰辅酶A莽草酸酯/奎宁酸羟基肉桂酰转移酶下调;差异代谢物阿魏酸、松柏醇、芥子醇下调。脱落酸生物合成和代谢过程中,沙泥田烟叶差异表达蛋白八氢番茄红素脱氢酶、玉米黄质环氧化酶、9-顺式环氧类胡萝卜素双加氧酶、黄氧素脱氢酶下调;差异代谢物红花菜豆酸、二氢红花菜豆酸下调。【结论】与紫色土烤烟上部叶相比,沙泥田烤烟上部叶生长过程中更易受环境胁迫,导致烟叶素质下降,脱落酸合成增加,激素信号激活,酚类代谢增强,PPO活性上升,在烘烤过程中易导致酶促褐变更加剧烈,从而造成烤后烟叶易挂灰。

烤烟品种K326上部叶烤后单叶重与感官质量的关系

为探索张家界市上部烟适宜的单叶重,以主栽品种K326为研究对象,设置不同单叶重区间,分析了单叶重与烟叶主要物理特性及感官质量的关系,确定了适宜的单叶重。结果表明:综合各单叶重对烟叶物理性状、感官质量的影响可知,高峰试验点单叶重为8~10、>10~12、>12~14 g时均表现较优,江垭试验点单叶重为8~10、>10~12 g时上部叶质量较好,可用性较高。根据叶长与单叶重的相关性,得出张家界烟区适宜的叶长区间:高峰试验点可将上部叶叶长在51.25~67.82 cm的占比、江垭试验点可将上部叶叶长在51.21~63.13 cm的占比作为技术调控目标。

烤烟上部6片烟叶一次性采收成熟度的模糊综合评价

为明确烤烟上部烟叶一次性采收的适宜成熟度,以湖南桂阳烟区种植的‘云烟87’为材料,设计低成熟度(M1)、中成熟度(M2)、高成熟度(M3)3个处理,开展6片上部烟叶采烤成熟度试验,并采用模糊评价方法对烤后烟叶质量和经济性状进行综合评价。结果表明,随上部烟叶采收成熟度提高,鲜烟叶的SPAD值下降;烤后烟叶微带青比例下降,杂色烟叶比例增加;烟叶成熟度提高,结构变为疏松,油分增多;烟叶单叶质量、厚度、叶面积质量、平衡含水率降低;烟叶总糖、还原糖、钾、淀粉含量下降,烟碱含量增加,化学成分可用性提高;但烟叶产量和产值下降。M2处理的外观质量指数较M1、M3分别高6.18%、-2.13%,物理性状指数较M1、M3分别高2.35%、5.30%,化学成分可用性指数分别高30.86%、4.55%,评吸总分分别高10.12%、0.50%,经济性状指数分别高8.96%、12.97%,烟叶质量指数分别高12.53%、1.16%,经济效果综合指数分别高10.11%、6.98%。综合来看,湖南桂阳烟区‘云烟87’上部6片烟叶一次性采收成熟度以M2较为适宜,即叶面变黄50%~80%,主脉变白50%~80%,支脉变白30%~50%,部分茸毛脱落,成熟斑较多;SPAD值在20.44~30.79可作为指导稻茬烤烟6片上部烟叶适宜采收成熟度的参考指标。

基于文献计量学的上部烟叶可用性知识图谱分析

上部叶质量对烤烟产量和品质具有重要影响,提高上部叶可用性是烟草行业亟待解决的热点难题。以中国知网(CNKI)中研究上部烟叶品质的文献为基础,通过CiteSpace软件,采用文献计量学的方法构建作者、机构、关键词等共现知识图谱,对烤烟上部叶可用性研究领域的研究现状及热点前沿进行分析。结果表明,提高上部叶可用性的研究一直是烟草行业高质量发展亟待解决的问题,2020—2023年稳定在70篇左右。上部叶可用性领域研究的主要方向是提升烟叶感官品质和外观质量、成熟采收、调制烘烤等方面。合理打顶留叶、成熟采收、科学烘烤是提高上部叶可用性的关键技术措施,今后可更加关注有机肥施用、烟田质量提升等对上部叶可用性提升的研究机制。

湘西烤烟上部叶烟碱含量特征及其与气象因子的关系

收集2007—2022年湘西3个主要产烟县烤烟生长季(4—9月)的主要气象数据,以及2015与2017—2022年卷烟工业公司调拨取样检测的烟叶化学成分数据,分析湘西烟区上部烟叶烟碱含量特征及其与主要气象因子的关系。结果表明:湘西烟区3个主产烟县烤烟生长季的气温总体表现出较高的稳定性,但龙山、花垣和永顺8月的积温年际间变异系数分别达到75.17%、75.32%和71.85%;龙山、永顺县6月累积日照时数的年际间变化最大,变异系数分别为43.21%和39.17%,花垣县9月累积日照时数的年际间变化最大,变异系数为36.57%;4—9月降水量的年际间变化相对较大,不同县的降水分布存在差异,龙山县为前期降水偏多,永顺和花垣后期降水偏多。3个主产烟县上部烟叶烟碱含量偏高和糖碱比偏低的样本所占比例分别为90.5%和85.7%。烤烟生育后期降水量与烟叶烟碱含量显著正相关(r=0.494,P=0.023),8—9月的降水量是解释烟碱含量变化的唯一显著变量,可解释24.4%的烟碱含量变化(偏高)。研究结果可为湘西烤烟烟碱含量的栽培调控以及烟田生育后期的水分管理等提供参考。

钾肥与赤霉素互作对烟株生长发育与上部烟叶质量的影响

【目的】探明钾肥与赤霉素互作对烟株生长发育与上部烟叶质量的影响,为改善上部烟叶品质提供理论支撑。【方法】以云烟87为试材,采用随机区组试验,设置CK:常规生产操作;TK_(1):常规生产操作,成熟期喷施2 g/kg糖醇螯合钾;TK_(2):常规生产操作,基肥增施草木灰1500 kg/hm^(2),打顶期喷施20 mg/kg赤霉素;TK_(3):常规生产操作,基肥增施草木灰1500 kg/hm^(2),打顶期喷施20 mg/kg赤霉素和成熟期喷施2 g/kg糖醇螯合钾4个处理,分析不同处理对烤烟上部烟叶的田间农艺性状、生理指标、烤后烟叶的化学成分、经济性状及土壤养分含量的影响。【结果】成熟期,与CK相比,TK_(1)、TK_(2)和TK_(3)处理均提高上部6片烟叶的叶面积,增幅分别为0.79%、14.91%和20.88%;TK_(1)处理较CK降低上部叶开片度,TK_(2)和TK_(3)处理分别提高0.73%和2.35%。相较CK,TK_(1)、TK_(2)和TK_(3)处理烤后烟叶的钾含量分别显著提高6.63%、12.15%和16.02%(P<0.05),上等烟率分别增加0.70%、17.53%和54.24%,烟碱含量分别降低10.86%、16.85%和15.74%,糖碱比分别提高2.97%、21.93%和25.65%,钾氯比分别提高19.65%、15.79%和27.72%。【结论】相较于单纯提升基肥施钾量或叶面钾肥与赤霉素的互作,基肥中增施草木灰并结合打顶期喷施赤霉素与成熟期喷施糖醇螯合钾的协同措施更有利于提高上部烟叶的叶面积、开片度与钾含量,优化糖碱比和钾氯比,降低烟碱含量,且能显著提高上等烟比例,是提升烟叶品质的有效方法。

微生物酶制剂对上部烟叶醇化品质的影响

为改善烟叶醇化品质,以低次红花大金元上部烟叶为试材,将BioApex微生物酶应用于烟叶醇化中,比较醇化烟叶的常规化学成分、挥发性香气成分和感官质量的变化。结果表明,添加微生物酶制剂会增加除氯以外的其他常规化学成分含量;同时降低了两糖差,使烟叶成分更加协调。各微生物酶制剂处理烟叶中还原糖、水溶性糖含量与CK相比均显著增加,但醇化时间延长会显著降低烟碱和水溶性糖含量。微生物酶制剂处理增加了烟叶中芳香族氨基酸降解产物、类胡萝卜素降解产物、美拉德反应产物含量。与CK相比,0.5%、1.0%和2.0%微生物酶制剂处理(90 d)明显改善了烟叶的感官质量。综上所述,微生物酶制剂能够促进烟叶内含物质的转化,提升红花大金元上部烟叶的品质。该研究可为烟叶微生物酶制剂发酵工艺在工业中的应用提供理论基础。

烤烟上部烟叶带茎采收适宜留叶数研究

为提高上部烟可用性,探明上部烟适宜采烤方式和留叶数,以‘云烟87’为试材,研究上部烟带茎与逐叶2种采收方式留叶3片(BJ3、BZ3)、4片(BJ4、BZ4)、5片(BJ5、BZ5)、6片(BJ6、BZ6)对烤后烟经济性状和烟叶质量的影响。研究表明,带茎采收烤后烟上等烟比例、均价、外观质量、主要化学成分协调性和感官质量总体好于逐叶采收。上等烟比例、均价上部烟带茎采收以BJ4最高,BJ5次之,且达到显著差异;逐叶采收以BZ4最高,BZ5次之,且BJ4比BZ4分别提高了9.11个百分点和0.80元/kg,BJ5比BZ5分别提高了5.10个百分点和0.14元/kg。外观质量总分带茎采收BJ5最高,BJ4次之;逐叶采收BZ5最高。主要化学成分还原糖、总糖含量和糖碱比带茎采收BJ4较适宜,BJ5次之,逐叶采收BZ5较适宜;感官评吸质量总分带茎采收BJ5最高(76.40分),逐叶采收BZ5最高(74.90分)。上部烟4~5片带茎采收的烟叶等级结构和内在质量优于逐叶采收。

提前采收对清甜香型烤烟上部叶质量及风格特征的影响

【目的】探索提前采收对清甜香型上部烟叶质量及风格特征的影响,为贵州清甜香型上部烟叶质量提升和风格特征彰显提供参考依据。【方法】以云烟87上部叶为材料,研究不同采收时间与成熟度(CK,正常采收/成熟;T1,提前4 d采收/尚熟;T2,提前8 d采收/欠熟)对烤后烟叶外观质量、致香物质含量和感官质量的影响,并解析贵州清甜香型上部烟叶风格特征彰显的物质基础。【结果】随采收时间的提前和成熟度的降低,烤后上部烟叶外观质量变差,主要表现在颜色、成熟度和叶片结构等方面;相较于CK,T1和T2处理烤后烟叶外观质量评价总分分别下降8.33%和22.92%。T1处理能显著提高烤后烟叶类胡萝卜素降解产物、美拉德反应产物、芳香族氨基酸降解产物、类西柏烷类降解产物、脂肪酸类物质、未分类致香物质、总致香物质(除新植二烯)及总致香物质含量(P<0.05,下同),其中总致香物质含量增幅7.54%,且有利于清甜香烟叶风格特征的彰显(评价分值增幅3.64%)。T2处理烤后烟叶总致香物质含量增幅为4.27%,但不利于烟叶风格特征的彰显。筛选出6种质体色素降解产物(藏红花醛、β-大马酮和巨豆三烯酮Ⅰ~Ⅳ)、3种芳香族氨基酸降解产物(苯乙醇、苯乙醛和2-甲氧基-4-乙烯基苯酚)和2种未分类致香物质[(E)-3-已烯-1-醇和壬醛]以彰显烟叶清甜香风格特征为主;2种美拉德反应产物[癸醛和1-(1H-吡咯-2-基)-乙酮]和1种类西柏烷类降解产物(茄酮)以彰显烟叶青香风格特征为主;2种脂肪酸类物质(棕榈酸和亚麻酸甲酯)以彰显烟叶甜香风格特征为主。CK和T1处理的感官质量评价总分显著高于T2处理,增幅分别为7.57%和7.41%,工业可用性和配方适配性均高于T2处理1个档次/水平。【结论】提前4 d采收有利于提高上部烟叶香气物质含量及风格特征彰显度,并筛选了16种风格特征彰显的标志物质,但提前4 d采收烤后烟叶外观质量变差;提前8 d采收烤后上部烟叶质量整体较差。因此,贵州清甜香型上部烟叶提前采收须根据烟叶质量调整相应烘烤工艺参数。