气调醇化过程中片烟细菌群落结构的变化

气调醇化是片烟醇化的一种方法。微生物尤其是细菌在片烟醇化过程中对烟叶的吸食品质起着至关重要的作用。为研究气调醇化过程中片烟细菌群落结构变化规律,利用Illumina MiSeq测序平台比较气调防霉杀虫阶段(S1)、气调醇化阶段(S2)及气调保质阶段(S3)共36份样品的细菌16S rDNA序列的多样性。结果表明,从S1到S3的过程中,片烟中细菌的物种丰富度和多样性水平呈增加趋势。S1阶段片烟的优势种群为鞘氨醇单胞菌属、假单胞菌属和甲基杆菌属,其占比在整个气调醇化过程中呈逐渐下降趋势;S2阶段的优势种群为芽孢杆菌属、鞘氨醇单胞菌属和伯克霍尔德菌属,其中芽孢杆菌属和伯克霍尔德菌属在整个气调醇化过程中占比呈先上升后下降的趋势;S3阶段细菌种群分布较为均匀。非度量多维尺度分析结果表明,3个醇化阶段的样品可以较明显地区分开来。可见,气调醇化过程中片烟的细菌种群组成非常丰富,不同醇化阶段活跃的微生物类群有所不同,鞘氨醇单胞菌属、假单胞菌属和甲基杆菌属主要在醇化前期参与了烟叶醇化过程,而芽孢杆菌属和伯克霍尔德菌属则主要在醇化后期发挥着微生物醇化的作用。

四段式气调醇化过程不同形态烟梗的质量变化

为了解不同形态烟梗在四段式气调醇化条件下的质量变化情况。以复烤后福建C梗和云南B梗的条状(梗条)和片状烟梗(梗片)为研究对象,通过四段式气调醇化技术(设计21.0%、<2.0%、6.0%~10.0%和<2.0%4组氧气浓度分别贮存不同时间),对比分析醇化过程中不同形态烟梗的质量差异。采用IlluminaMiSeq测序平台对醇化过程不同形态烟梗表面细菌16SrDNA进行高通量测序分析,跟踪分析醇化过程中不同形态烟梗的含水率和颜色变化,对比评价醇化后制得梗丝的感官质量。结果表明:①醇化过程中与梗条相比,梗片含水率和颜色较稳定,色差值变化小,转深速率较低;②四段式醇化过程不同形态烟梗的细菌群落优势菌门均为变形菌门,云南B梗和福建C梗共有的优势菌属为链霉菌属、甲基杆菌属、假单胞菌属和鞘氨醇单胞菌属4种,梗片醇化6~18个月的OTU数、Chao值和ACE值的平均值均大于梗条,细菌群落丰度高于梗条;③梗片醇化过程假单胞菌属、鞘氨醇单胞菌属和芽孢杆菌属3种优势产香菌属含量较高,对改善烟梗品质起到了有利作用。④醇化后,梗片制得的梗丝较梗条制得的梗丝杂气降低、刺激性减弱、口腔残留较少。

片烟四段式气调绿色醇化技术体系的构建

【背景和目的】烟叶醇化是改善烟叶品质、提升烟叶使用价值的重要环节。自然醇化是目前应用最为广泛的仓储醇化方式,但该方式仍存在片烟到达质量高点后质量下降较快、易发生霉变虫害、使用化学农药熏蒸等问题。【方法】以福建、云南、阿根廷等国内外主产烟区片烟作为试验材料,研究气调杀虫防霉、气调醇化、气调保质技术的最优氧气浓度,比较分析了不同醇化条件下片烟的感官质量、外观质量及pH值等品质因素。【结果】(1)气调杀虫防霉过程,将氧气浓度设置为2%以下,密封封存90天,可以有效抑制不同虫态的烟草甲及霉变的发生。(2)气调醇化过程,7%~9%氧气浓度气调醇化120天以上,可明显提升片烟感官质量,延缓片烟颜色过度转深。(3)气调保质过程,将氧气浓度调至2%以下并保持到片烟开垛,可有效保持片烟品质。(4)四段式气调醇化法较大程度延长了片烟质量周期,其适宜使用期比自然醇化至少延长15个月,延缓了片烟pH值的下降速率。(5)四段式气调醇化过程垛内相对湿度保持相对平稳,垛内氧气浓度可人工调节,垛内二氧化碳在无人工干预情况下持续升高。【结论】本研究建立的四段式气调醇化技术体系,既不使用剧毒化学农药熏蒸杀虫,又提高了片烟醇化质量,延长了片烟的适宜使用期和最佳使用期,并明确了不同产区片烟的科学使用策略,为片烟贮存提供了新的思路。

三种氧浓度气调下清香型烟叶化学成分的变化

选择3种清香型产地复烤烟叶,分别用2%以下氧浓度、6%~8%氧浓度和21%氧浓度气调养护醇化,分析烟叶采用3种气调方式醇化时化学成分的含量变化差异。结果表明,随着醇化进行,总植物碱含量变化较小,pH、多酚含量、氨基酸含量呈下降趋势,两糖比逐步上升;3种气调方式中,pH下降幅度、多酚消耗率和氨基酸消耗率均表现为21%氧浓度>6%~8%氧浓度>2%以下氧浓度,21%氧浓度气调的化学成分变化波动最大,2%以下氧浓度气调波动相对平缓;在高温季节,pH变幅、多酚消耗率、氨基酸消耗率都有一个加速变化的过程;3种清香型烟叶因为产地不同,常规化学成分差异较大,云南普洱B1F(A)烟叶、四川西昌B1F烟叶的pH、多酚含量和氨基酸含量明显大于福建龙岩B1F(A)烟叶。

不同醇化方式对片烟细菌群落结构的影响

为明确不同醇化方式的片烟细菌群落结构差异,以3个等级的片烟为材料,采用气调醇化和自然醇化2种方式进行仓储养护,以初始样为对照,利用MiSeq高通量测序对2种醇化方式的片烟细菌群落结构进行分析。结果表明,醇化3年后,2种醇化方式片烟中细菌的多样性水平降低,且气调醇化法低于自然醇化法;据非度量多维尺度分析,2种醇化方式的样品能明显地区分开来;甲基杆菌属、鞘氨醇单胞菌属占比在醇化过程中呈下降之势,在2种醇化方式之间的差异不显著;盐单胞菌属占比呈上升之势,且气调醇化显著高于自然醇化。

四段式气调贮存与常规贮存条件下烤烟片烟的质量差异分析

对四段式气调贮存与常规贮存2种方式下烤烟片烟的质量差异进行试验研究。结果表明,与常规贮存方法相比,四段式烟叶气调醇化贮存技术能较好地延缓片烟颜色转深程度,明显提高烤烟片烟的醇化质量,有效延缓片烟质量下降的速度,延长已达到适宜醇化质量片烟的保质期。

Effect of Controlled Atmosphere Storage(CAS)Technology of Flue-cured Tobacco Laminas on the Alcoholization Quality of Tobacco

To achieve the continuous maintainence of optimum quality state of flue- cured tobacco laminas and the effective regulation and control on alcoholization time for controlled atmosphere storage （CAS） method in the process of storage, the lam- ina samples of natural alcoholization for 1 year were selected. Comparable analysis on the appearance quality, chemical components and sensory quality of flue-cured tobacco laminas in the process of alcoholization was carried out by using the meth- ods of CAS and natural alcoholization. The results showed that appearance and color through the treatment of natural alcoholization were deep, browning and ac- companied by the phenomenon of oil, while color scale of flue-cured tobacco lami- nas through the treatment of CAS was uniform, fullness was better, and these two methods were close or identical after opening for 3 months. The contents of total sugar and reducing sugar during the process of alcoholization were also gradually decreased, but the ratio of reducing sugar to total sugar of laminas via CAS was higher than that of the natural alcoholization treatment. Compared with the natural alcoholization,the descending trends of total nitrogen and nicotine contents during CAS were gentler, the ratio via CAS was closer to 1, and the coordination of chemical components was more superior. During the period of alcoholization for 6 to 12 months, sensory quality of laminas via the natural alcoholization treatment was more superior than that of CAS treatment. However, after 18 months of alcoholiza- tion, sensory quality of laminas via the CAS treatment was more superior than that of the natural alcoholization treatment, and the CAS treatment could improve opti- mum sensory quality by 0.5 to 1.5 scores. Additionally, the CAS treatment could prolong the time of optimum alcoholization quality for 6 months, compared with the treatment of natural alcoholization. The CAS method could influence the alcohoJiza- tion quality of flue-cured tobacco laminas and prolong the retention period of opti- mum quality status for flue-cured tobacco laminas by regulating the environmental aas composition, thereby realizin.q quality control of flue-cured tobacco laminas.