Recent years have witnessed major advances in heated tobacco products. However, optimizing the aroma release and smoke generation of these products remains a formidable challenge. Alkali metal salts have emerged as effective catalysts for pyrolysis, demonstrating the dual benefits of enhanced catalytic efficiency and alleviating coke deposition. To effectively illustrate the effect of adding salt on the low-temperature catalytic pyrolysis performance of reconstituted tobacco sheets, thermogravimetric analysis and pyrolysis gas chromatography-mass spectrometry analyses were carried out, and the Flynn-Wall-Ozawa method and the Kissinger method were also applied to calculate reaction kinetics. The addition of the sodium (Na) salt or potassium (K) salt in reconstituted tobacco sheets was observed to significantly decrease the temperature corresponding to the maximum weight loss rate and increase the total weight loss with the range of 100-300 degrees C. Meanwhile, the content of key components in the pyrolysis gas gradually increased, indicating that the ability to catalyze cellulose and lignin pyrolysis improved. The results of dynamic analysis show that the apparent activation energy of reconstituted tobacco sheets decreased by an average of 80.95 or 49.12 kJmol-1 after adding Na or K salt when the conversion rate was 0.1-0.8. The approach reported herein not only exhibits a fundamental advance in the low-temperature pyrolysis of reconstituted tobacco sheets for heated tobacco products but also increases the concentration of pyrolysis gas and aromatic substances.

The puff-by-puff release stability of aerosols generated by heated tobacco products (HTPs) is a key factor influencing consumers' sensory experience. This study systematically investigates the effects of different heating modes and the compatibility between heated tobacco product sticks and their Compatible devices on aerosol release stability. By quantifying the puff-by-puff release concentrations of key components in HTPs aerosols, the release stability is comprehensively evaluated via the relative standard deviation (RSD) and relative mean absolute deviation(RMAD). The results show that: (1) Compared with peripheral heating, central heating provides higher puff-by-puff release stability of HTPs aerosols;(2) Under the selected experimental conditions, electromagnetic central heating device exhibits good compatibility with two distinct types of HTPs sticks; (3) After optimizing the heating temperature profile, a resistive central heating device could also be adapted to the two distinct HTPs sticks, ensuring consistent and uniform puff-by-puff aerosol release. Heating modes and compatibility between stick and device are critical determinants of aerosol release stability. These findings offer theoretical and technical support for the optimization and regulation of HTPs systems, thereby helping to effectively enhance consumers' sensory perception.

In order to develop pyridone compounds with good antioxidant ability and bacteriostatic activity, the compounds 3-(benzyloxy)-2-ethyl-1-propylpyridin-4(1H)-one (5a) to 3-(benzyloxy)-2-ethyl-1-(4-methylbenzyl)pyridin-4(1H)-one (5e) were obtained through two steps reaction. The structures were confirmed using nuclear magnetic resonance (1H-NMR, 13C-NMR), Fourier transform infrared spectrometer (FT-IR), and high resolution mass spectrometry (HRMS). The antioxidant ability of compounds 5a-5e was identified by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radicals (OH) methods. Turbidimeter method and mycelial growth rate method were used for the determination of in vitro bacteriostatic activity of compounds 5a-5e against gram-negative bacteria [Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa)], gram-positive bacteria [Bacillus subtilis (B. subtilis), Staphylococcus aureus (S. aureus)], and fungi [Botrytis cinerea (B. cinerea)]. The antioxidant results showed that at the concentration of 2 mg/mL, compounds 3-(benzyloxy)-2-ethyl-1-(furan-2-ylmethyl)pyridin-4(1H)-one (5c) and 5e exhibited stronger free radical scavenging ability than ethyl maltol. The bacteriostatic activity results showed that compounds 5a and 5e showed good bacteriostatic activities against S. aureus and B. cinerea. Molecular docking results showed that compounds 5a and 5e inhibit the activity of pyruvate dehydrogenase, thereby achieving bacteriostatic effect. This study not only synthesized novel heterocyclic compounds, but also provided new ideas and references for the development and selection of bacteriostatic agents.

In this study we developed a novel carrier material that can be used to regulate nicotine release profile to provide a more constant release. Bacterial cellulose (BC) was produced by fermentation of tobacco waste, nicotine was derived from the backfilling of tobacco extracts. Citric acid (CA) has been used to react with bacterial cellulose to prepare an aerogel (CA-BC) which showed to possess sustained nicotine release by varying CA and its crosslinking ratio with BC. Aerogels prepared at 10% CA/BC ratios during crosslinking exhibited significant sustained nicotine release effects. Another notable finding was that the sustained-release of nicotine for the CA-BC aerogel with high nicotine contents significantly outperformed that of low nicotine contents. The Weibull model and Gallagher-Corrigan model were used to elucidate the mechanism of nicotine dissolution from CA-BC aerogels. Material characterization revealed that the CA-BC aerogel had an improved thermal stability and decreased water absorption, a 3D fiber network structure at the microscopic level with an optimal average pore size of 30 μm was used to explain this difference.

Isoconversional kinetic analysis of a chemical reaction can effectively evaluate the activation energies, but it cannot directly determine the kinetic mechanism function (KMF). This study focuses on the complementary use of the Friedman isoconversional method and modified empirical KMF to investigate the kinetics of tobacco waste pyrolysis. The systematical analysis of the modified empirical KMF shows its abundant flexibility in describing various complex kinetics, as evidenced by diverse shape characteristics of kinetic curves. The kinetic results of tobacco waste pyrolysis were obtained by the integrated approach of the Friedman isoconversional method and modified empirical KMF: activation energies ranging from 176.3 to 352.5 kJ & sdot;mol-1 in the alpha range between 0.05 and 0.95 and the KMF for tobacco waste pyrolysis being f(alpha) = alpha- 1.8931 & sdot;(1-1.0206 & sdot;alpha)5.9108.The combination of the Friedman isoconversional method with the modified empirical KMF serves as an effective method for conducting the comprehensive kinetic analysis of lignocellulosic biomass pyrolysis. The results can be used to establish the comprehensive and accurate chemical model, which is helpful for accurate numerical simulation of the biomass pyrolysis process, enabling the optimization of pyrolysis reactor configurations and operation conditions based on the numerical simulation results, thereby facilitating the industrial application of tobacco waste conversion.

This study aimed to isolate an efficient bacterial cellulose (BC)-producing strain from rotten mango, optimize BC production though single-factor tests followed by Box-Behnken design (BBD) under agitated culture conditions using tobacco waste extract as the medium, and conduct the characterization of BC via Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Komagataeibacter sp. XMZ1 with a high-efficiency BC biosynthesis capacity was successfully isolated from rotten mango. Subsequently, BBD was utilized to optimize the co-supplementation of lactic acid, ethanol, and yeast extract, demonstrating this statistical approach to be a reliable tool for both optimization and predictive modeling of BC yield. The optimized medium containing 2.1 g/L lactic acid, 1

Glycolic acid finds extensive applications in the production of biodegradable polymers, pharmaceuticals, and fine chemicals. In this study, a Pt catalyst supported on Sn-Beta zeolite (Pt/Sn-Beta) was developed to achieve...

In this study, a strain isolated from the surface of flue-cured tobacco leaves, identified as Bacillus velezensis HJ-16, was applied in the solid-state fermentation of tobacco leaves. This strain, known for producing thermally stable enzymes, including amylase, cellulase, and protease, significantly improved the sensory qualities of tobacco, enhancing aromatic intensity, density, and softness, while reducing irritation. Whole-genome sequencing and functional annotation revealed that B. velezensis HJ-16 possesses a single circular chromosome containing genes associated with enzyme production and metabolic activities, particularly in carbohydrate metabolism and amino acid metabolism. Untargeted metabolomics analysis identified significant changes in non-volatile metabolites induced by fermentation. These metabolites were enriched in pathways related to flavonoid biosynthesis, alkaloid biosynthesis, aromatic amino acid metabolism, lipid metabolism, and carbon metabolism. Metagenomic analysis showed that Bacillus became the dominant genus on the tobacco leaf surface following inoculation with B. velezensis HJ-16, altering the microbial community composition, reducing diversity and evenness, and enhancing microbial metabolic activity. These findings underscore the potential of B. velezensis HJ-16 as a biotechnological tool to improve tobacco leaf quality.

In order to develop burnt sweet fragrance compounds with stability. In this paper, nine ethyl maltol succinate diester compounds 2-ethyl-4-oxo-4H-pyran-3-yl phenethyl succinate (5a)similar to 2-ethyl-4-oxo-4H-pyran-3-yl (2-methylallyl) succinate (5i) were obtained by a two-step method using succinic anhydride, flavor alcohols and ethyl maltol as raw materials, and were subjected to structural characterization, thermal stability and in vitro antioxidant studies. The results showed that compounds 5a similar to 5i possessed a burnt sweet fragrance as well as other fragrances. Compounds 5a and cinnamyl (2-ethyl-4-oxo4H-pyran-3-yl) succinate (5b) had a highest weight loss at a temperature higher than that of raw materials, and a large amount of substances such as ethyl maltol and flavor alcohols were produced during pyrolysis. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) and center dot OH scavenging abilities of compound 5a are higher than those of compounds 5b similar to 5i and ethyl maltol. In summary, compound 5a has a burnt sweet fragrance, and exhibits high thermal stability and in vitro antioxidant capacity. This work may provide a new method to improve the stability of spices and expand their multifunctional application.

Understanding the puff-by-puff delivery mechanisms of key components of heated tobacco products is critical to developing product designs. This study investigates the puff-by-puff release patterns of key components in Natural Smoke Cigarettes (NSCs), which are designed to deliver nicotine without combustion by reducing oxygen content, utilizing a 30-s puff interval, a 2-s puff duration, and a 55 mL puff volume to simulate realistic smoking conditions. By establishing models to analyze the variation of nicotine, glycerol, 1,2-propylene glycol (PG), and water in different functional sections of the cigarette under controlled smoking conditions. These sections include the tobacco, hollow, cooling, and filter sections, constituting the structure of NSCs. In addition, the model calculates the port-by-port release of the components in the flue gas aerosol and compares it with the measured value. The results showed that: The retention amount in the tobacco section showed a steep decline in the first three puffs, with an overall exponential decrease. The amounts in the other sections were consistent, increasing in the first two puffs and then stabilizing. The retention amount decreased linearly with each puff, with a similar pattern across sections. The release amount peaked at the fourth to fifth puffs and then stabilized. The retention amount in the tobacco section declined exponentially in the first three puffs. It peaked in the second to third puffs in other sections, then decreased with each subsequent puff. The retention amount in the tobacco section showed a significant decline in the first puff, stabilizing at around 4 mg. In other sections, it peaked at the first puff and then rapidly declined. These findings can inform the development of reduced-harm smoking products and contribute to a better understanding of the dynamics of smoke generation. Additionally, the study offers a reference for the puff-by-puff release stability of NSCs and the improvement of consumers’ sensory quality.

The complete utilization of lignocellulose is a sustainable key for bio-refineries, where the utilization of evitable lignin is a great challenge owing to its structural complexity. Here, the effect of Cu and Zn-loaded mesoporous gamma-Al2O3 catalysts was examined for the first time for the hydrothermal liquefaction of alkali lignin in an ethanol/water solvent system. It showed excellent performance towards the liquefaction as compared to that of (commercial) com-5Cu/gamma-Al2O3 catalyst. Here, the bio-oil yield was observed to be 47.7 wt% for com-5Cu/Al catalyst which was increased to 59.1% for syn-5Cu/Al. It was increased substantially to 65.4 wt% for syn-10Cu/Al. However, only a 40 wt% bio-oil yield was found for the non-catalytic (NC) reaction. Additionally, a further significant improvement to 74.7 wt% was noticed for Zn (5 wt%) modified syn-10Cu/Al catalyst. Here, the screening of the water-ethanol mixture, and reaction parameters were also evaluated which showed a small increase in bio-oil yield to 77.4 wt% for ethanol/water (75/25, v/v). The GC-MS analysis of bio-oil exhibited the high specificity of vanillin (69.3%) for syn-10Cu-5Zn/Al. The H-1 NMR and FT-IR investigation also validate the diverse functionality of bio-oils. The reusability of the optimum catalyst (syn-10Cu-5Zn/Al) was also tested for three successive catalytic cycles that exhibited the good performance of the catalyst up to the second cycle.

The primary function of plant fibers in reconstituted tobacco is to enhance the physical strength, and it can quite modify their physical properties. This study demonstrated the effect of various plant fibers and their beating degrees on the physical properties of reconstituted tobacco. Tensile index, burst index, uniformity, tensile stiffness orientation, and thermal conductivity coefficient were examined. The result revealed that the mechanical properties of reconstituted tobacco varied according to the type and beating degree of the fibers. The mechanical properties of softwood, cotton, and bast fibers showed an initial increase followed by a decrease with increasing beating degree, while bamboo fiber showed a continuous improvement in mechanical properties proportional to the beating degree. Conversely, hardwood fiber displayed an inverse relationship with its beating degree. Under identical beating conditions, reconstituted tobacco containing softwood fibers showed the greatest improvement in tensile properties, achieving the highest tensile strength, thermal conductivity, and specific heat capacity. In particular, when softwood fibers were beaten to 50 °SR, the physical properties of the reconstituted tobacco peaked, with longitudinal and transverse tensile indices improving by 42.48% and 12.11%, respectively. Additionally, the bursting resistance index increased by 61.93%, and the thermal conductivity coefficient increased by 5.94%.

Development of low temperature catalytic pyrolysis technology for heated tobacco sheets is expected to increase the aroma of heated tobacco products and improve their overall smoking quality. In this study, the low temperature pyrolysis performances of heated tobacco sheets catalyzed by various anionic sodium salts were investigated using TG-DTG, Py-GC-MS technology and smoke routine chemical composition analysis. The results showed that the total weight loss between 100°C and 300°C increased by 7.8%–13.15% after adding various anionic sodium salts, among which, sodium acetate and sodium tartrate showed a relatively higher weight loss. The relative content of free hydroxyacetone, furfuryl alcohol, butyrolactone and megastigmatrienone in the pyrolysis gas increased, while the relative content of free nicotine decreased. With the change of anionic species, the catalytic decomposition ability of cellulose, lignin, and other substances may change, resulting in the distribution alteration of compounds in the pyrolysis gas. After adding sodium acetate and sodium citrate, the release of total particulate matter (TPM), glycerol, and nicotine in flue gas increased. Overall, the addition of sodium acetate and sodium citrate showed a higher low temperature pyrolysis performance of heated tobacco sheets. The research results in this paper provide data support for changing the low temperature catalytic pyrolysis performance of heated tobacco sheets by adjusting the type of anions in sodium salts.

For the aroma enhancement research of heated cigarettes, it is worth exploring whether tobacco can be pyrolyzed into pyrolysis liquids containing a large number of volatile aroma components. In this study, tobacco pyrolysis liquids were prepared in subcritical/supercritical ethanol, and their applications in the aroma enhancement of heated cigarettes were investigated. The optimal conditions of supercritical liquefaction reactions were determined by optimizing the reaction time, liquid/solid mass ratio and temperature conditions. Moreover, the effect of supercritical liquefaction conditions on volatile aroma components in tobacco pyrolysis liquids was investigated by GC-MS. The results indicated that the reaction temperature had the most significant impact on the tobacco pyrolysis reaction, and higher reaction temperature promoted the pyrolysis conversion of tobacco, resulting in enhanced tobacco conversion and a high content of volatile components in the tobacco pyrolysis liquid. The optimal reaction conditions for the preparation of tobacco pyrolysis liquid were found to be a temperature of 220°C, a liquid/solid mass ratio = 15, and a 2-h reaction time. Meanwhile, the content of ester compounds and nicotine in the tobacco pyrolysis liquid increased significantly with the increase of reaction temperature. Sub/supercritical ethanol treatment significantly destroyed the surface structure of tobacco, and the degree of tobacco depolymerization increased when temperature rised. The analysis of aroma compounds in the smoke of heated cigarettes indicated that the tobacco pyrolysis liquid could significantly increase the release of aromatic substances and has a significant aroma-enhancing effect. This article proposed and prepared tobacco pyrolysis liquid in subcritical/supercritical ethanol and explored its potential application in the aroma enhancement of heated cigarettes, offering a new route for flavor enhancement technology for this type of product.

UV-B radiation can induce the accumulation of many secondary metabolites, including flavonoids, in plants to protect them from oxidative damage. BRI1-EMS-SUPPRESSOR1 (BES1) has been shown to mediate the biosynthesis of flavonoids in response to UV-B. However, the detailed mechanism by which it acts still needs to be further elucidated. Here, we revealed that UV-B significantly inhibited the transcription of multiple transcription factor genes in tobacco, including NtMYB27, which was subsequently shown to be a repressor of flavonoids synthesis in tobacco. We further demonstrated that NtBES1 directly binds to the E-box motifs present in the promoter of NtMYB27 to mediate its transcriptional repression upon UV-B exposure. The UV-B-repressed NtMYB27 could bind to the ACCT-containing element (ACE) in the promoters of Nt4CL and NtCHS and served as a modulator that promoted the biosynthesis of lignin and chlorogenic acid (CGA) but inhibited the accumulation of flavonoids in tobacco. The expression of NtMYB27 was also significantly repressed by heat stress, suggesting its putative roles in regulating heat-induced flavonoids accumulation. Taken together, our results revealed the role of NtBES1 and NtMYB27 in regulating the synthesis of flavonoids during the plant response to UV-B radiation in tobacco.

The low temperature catalytic pyrolysis performances of heated tobacco sheets by alkali/alkaline earth metal were investigated by TG-FT-IR and Py-GC-MS. Thermogravimetric analysis showed that the maximum weight loss rate temperature of the heated tobacco sheets significantly reduced from 328 degrees C to 292 degrees C catalyzed by alkali metal Na or K catalysts, and the weight loss between 100 and 300 degrees C increased by 48.83% and 40.05% respectively. While alkaline earth metal Mg or Ca catalysts exerted less influence on the maximum weight loss rate temperature and the weight loss between 100 and 300 degrees C reduced slightly. The online infrared absorption band of pyrolysis gas shifted to lower temperature and the concentration of pyrolysis gas increased over Na catalysts, which matched well with TG results. Moreover, the concentration of carbonyl compounds and compounds containing C-O bonds in pyrolysis gas increased significantly. The content of 2-furanmethanol, butyrolactone and megastigmatrienone in pyrolysis gas increased under the assistance of alkali metal Na or K. Model compounds research confirmed that alkali metal could catalyze low temperature pyrolysis of cellulose in heated tobacco sheets. These results demonstrated that the pyrolysis of heated tobacco sheets could be catalyzed by alkali metal catalysts at low temperature, increasing the concentration of pyrolysis gas and aroma substance. This research provided a new idea for the study of aroma and concentration enhancement of heated cigarettes through catalytic technology.

The AP2/ERF (APETALA2/ETHYLENE RESPONSE FACTOR) transcription factors play multiple roles in modulating the biosynthesis of diverse specialized metabolites in response to various environmental stresses. ERF13 has been shown to participate in plant resistance to biotic stress as well as in repressing the synthesis of fatty acid. However, its full roles in regulating plant metabolism and stress resistance still remains to be further studied. In this study, we identified two NtERF genes from N. tabacum genome that belong to Ⅸa subgroup of ERF family. Over-expression and knock-out of NtERF13a showed that NtERF13a could enhance plant resistance to salt and drought stresses, as well as promoted the biosynthesis of chlorogenic acid (CGA), flavonoids, and lignin in tobacco. Transcriptome analysis between WT and NtERF13a-OE plants revealed 6 differentially expressed genes (DEGs) that encode enzymes catalyzing the key steps of phenylpropanoid pathway. Chromatin immunoprecipitation, Y1H, and Dual-Luc assays further clarified that NtERF13a could directly bind to the fragments containing GCC box or DRE element in the promoters of NtHCT, NtF3'H, and NtANS genes to induce the transcription of these genes. Knock-out of NtHCT, NtF3'H, or NtANS in the NtERF13a-OE background significantly repressed the increase of phenylpropanoid compound contents caused by over-expression of NtERF13a, indicating that the promotion of NtERF13a on the phenylpropanoid compound contents depends on the activity of NtHCT, NtF3'H, and NtANS. Our study demonstrated new roles of NtERF13a in promoting plant resistance to abiotic stresses, and provided a promising target for modulating the biosynthesis of phenylpropanoid compounds in tobacco.

以烟草废弃物制备的细菌纤维素为原料,利用全自动测色色差计、场发射扫描电子显微镜、同步热分析仪等对经自然干燥(NAD)、热风干燥(HAD)、真空冷冻干燥(VFD)、-20℃预冻-真空冷冻干燥(VFD-20)、-80℃预冻-真空冷冻干燥(VFD-80)和液氮预冻-真空冷冻干燥(VFD-FLN)处理后的细菌纤维素进行形貌与结构表征,利用蒸馏萃取-气质联用法分析不同干燥方式对烟用细菌纤维素香味成分的影响.结果表明:经VFD-FLN处理的细菌纤维素在原有三维网状结构基础上能较好地保持纤维长度;经VFD、VFD-20 和VFD-80 处理的细菌纤维素的三维空间结构保持较好,但纤维长度变短;经NAD和HAD处理的细菌纤维素空间结构被破坏,导致其复水率和溶胀率最小.经NAD处理的细菌纤维素色泽保留情况最好且其挥发性香味成分主要为酸性物质,相对含量高达97.93%;经VFD处理的细菌纤维素中挥发性香味成分相对含量次之,主要为类胡萝卜素降解产物、萜类化合物降解产物和苯丙氨酸类降解产物;HAD的干燥速度最快,但经其处理的细菌纤维素中挥发性香味成分相对含量最低.

Five psoralen derivatives were synthesized and the structures of them were characterized by H NMR and C NMR. The antioxidant properties of the compounds were tested by inhibiting the free radical-initiated DNA oxidation and quenching the radical reaction. The results showed that the effective stoichiometric factors ( n ) of the compounds V and IV could reach 2.00 and 2.11 in the system of inhibiting the DNA oxidation reaction initiated by 2,2’-Azobis(2-methylpropionamidine) dihydrochloride (AAPH). In the inhibition of •OH-oxidation of the DNA system, compounds I ~ V showed antioxidant properties. The thiobarbituric acid absorbance (TBARS) per-centages of compounds IV and V were 76.19% and 78.84%, which were comparable to Trolox (71%). Compounds I ~ V could also in-hibit Cu2+/GSH-oxidation of DNA, and all compounds exhibited good antioxidant properties except compound II (94.00%). All the five compounds were able to trap diammonium 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonate) salt radical (ABTS), 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) and 2,6-di-tert-butyl-alpha-(3,5-di-tert-butyl-4-oxo-2,5-cyclohexadien-p-tolylox radical (galvinoxyl•). The ability of compounds I ~ V to scavenge those free radicals can be measured by the k values. The k values ranged from 0.07 to 0.82 in scavenging ABTS, galvinoxyl and DPPH radicals, respectively.

为探究低氧条件下加热温度对烟草热解释放物及固相残余物理化结构演变的影响规律,使用管式炉反应器实现低氧条件下不同加热温度再造烟叶烟气成分捕集及固相残余物制备,通过GC-MS分析系统完成代表性烟气成分检测,并采用多种分析表征技术检测固相残余物的微观结构和化学组成.结果表明:再造烟叶受热过程中,甘油、丙二醇、烟碱等基础物质受热后多直接转移至烟气气溶胶中,巴豆醛、羟基丙酮、异戊二烯等随温度升高释放量增加,萘随温度升高释放量降低,愈创木酚、甲酚、苯酚、2,3-丁二酮、1-羟基-2-丁酮、2(5H)-呋喃酮等随温度变化呈现波动性,烟气中以异戊二烯为代表的低温裂解挥发性化合物相对含量随温度的升高而增加;固相残余物纤维骨架灰化程度随温度的升高而增加,370℃之前再造烟叶主要以低沸点物质的挥发/蒸馏及半纤维素和纤维素的脱羟/脱羧反应为主,随温度升高热解过程中存在氧化反应,且再造烟叶表面上更稳定的含氧官能团相对含量突增.