Chemical Components Of Tobacco Research Articles

Effects of Exocellobiohydrolase CBHA on Fermentation of Tobacco Leaves.

The quality of tobacco is directly affected by macromolecular content, fermentation is an effective method to improve biochemical properties. In this study, we utilized CBHA (cellobiohydrolase A) glycosylase, which was expressed by Pichia pastoris, as an additive for fermentation. The contents of main chemical components of tobacco leaves after fermentation were determined, and the changes of microbial community structure and abundance in tobacco leaves during fermentation were analyzed. The relationship between chemical composition and changes in microbial composition was investigated, and the function of bacteria and fungi in fermentation was predicted to identify possible metabolic pathways. After 48 h of CBHA fermentation, the contents of starch, cellulose and total nitrogen in tobacco leaf decreased by 17.60%, 28.91% and 16.05%, respectively. The microbial community structure changed significantly, with Aspergillus abundance decreasing significantly, while Filobasidum, Cladosporium, Bullera, Komagataella, etc., increased in CBHA treated group. Soluble sugar was most affected by microbial community in tobacco leaves, which was negatively correlated with starch, cellulose and total nitrogen. During the fermentation process, the relative abundance of metabolism-related functional genes increased, and the expressions of cellulase and endopeptidase also increased. The results showed that the changes of bacterial community and dominant microbial community on tobacco leaves affected the content of chemical components in tobacco leaves, and adding CBHA for fermentation had a positive effect on improving the quality of tobacco leaves.

Dissection of genetic architecture of nine hazardous component traits of mainstream smoke in tobacco (Nicotiana tabacum L.).

Tobacco (Nicotiana tabacum L.) use is the leading cause of preventable death, due to deleterious chemical components and smoke from tobacco products, and therefore reducing harmful chemical components in tobacco is one of the crucial tobacco breeding targets. However, due to complexity of tobacco smoke and unavailability of high-density genetic maps, the genetic architecture of representative hazardous smoke has not been fully dissected. The present study aimed to explore the genetic architecture of nine hazardous component traits of mainstream smoke through QTL mapping using 271 recombinant inbred lines (RILs) derived from K326 and Y3 in multiple environments. The analysis of genotype and genotype by environment interaction (GE) revealed substantially greater heritability over 95% contributed mostly by GE interaction effects. We also observed strong genetic correlations among most studied hazardous smoke traits, with the highest correlation coefficient of 0.84 between carbon monoxide and crotonaldehyde. Based on a published high-density genetic map, a total of 19 novel QTLs were detected for eight traits using a full QTL model, of which 17 QTLs showed significant additive effects, six showed significant additive-by-environment interaction effects, and one pair showed significant epistasis-by-environment interaction effect. Bioinformatics analysis of sequence in QTL region predicted six genes as candidates for four traits, of which Nt21g04598.1, Nt21g04600.1, and Nt21g04601.1 had pleiotropic effects on PHE and TAR.

The bacterial succession and its role in flavor compounds formation during the fermentation of cigar tobacco leaves

Fermentation is the key process required for developing the characteristic properties of cigar tobacco leaves, complex microorganisms are involved in this process. However, the microbial fermentation mechanisms during the fermentation process have not been well-characterized. This study investigated the dynamic changes in conventional chemical composition, flavor compounds, and bacterial community during the fermentation of cigar tobacco leaves from Hainan and Sichuan provinces in China, as well as the potential roles of bacteria. Fermentation resulted in a reduction of conventional chemical components in tobacco leaves, with the exception of a noteworthy increase in insoluble protein content. Furthermore, the levels of 10 organic acids and 19 amino acids showed a significant decrease, whereas the concentration of 30 aromatic substances exhibited a unimodal trend. Before fermentation, the bacterial community structures and dominant bacteria in Hainan and Sichuan tobacco leaves differed significantly. As fermentation progressed, the community structures in the two regions became relatively similar, with Delftia, Ochrobactrum, Rhodococcus, and Stenotrophomonas being dominant. Furthermore, a total of 12 functional bacterial genera were identified in Hainan and Sichuan tobacco leaves using bidirectional orthogonal partial least squares (O2PLS) analysis. Delftia, Ochrobactrum, and Rhodococcus demonstrated a significant negative correlation with oleic acid and linoleic acid, while Stenotrophomonas and Delftia showed a significant negative correlation with undesirable amino acids, such as Ala and Glu. In addition, Bacillus showed a positive correlation with benzaldehyde, while Kocuria displayed a positive correlation with 2-acetylfuran, isophorone, 2, 6-nonadienal, and β-damascenone. The co-occurrence network analysis of microorganisms revealed a prevalence of positive correlations within the bacterial network, with non-abundant bacteria potentially contributing to the stabilization of the bacterial community. These findings can improve the overall tobacco quality and provide a novel perspective on the utilization of microorganisms in the fermentation of cigar tobacco leaves.Graphical

Effects of fermentation medium on cigar filler.

The addition of medium during industrial fermentation can improve the quality of cigar tobacco leaves after agricultural fermentation. In this study, the cigar filler tobacco "Brazilian Frogstrips YA14" was used as the test material to determine the contents of main chemical components in cigar tobacco leaves after fermentations with the additions of water (control group) and a medium (test group), and the changes in the community structure and abundances of bacteria on tobacco leaves during the fermentation process were analyzed. The results of the study were as follows: 1) During the fermentation process, the protein content of tobacco leaves fluctuated slightly, basically stabilized at 19%-20%. 2) Under the impact of the medium, the total content of main amino acids in tobacco leaves showed a downward trend, and the difference of which between the control group and the test group was the most obvious on the fourth day of fermentation. 3) The change trend of the content of petroleum ether extract in cigar leaves for the control group was not obvious, and the content of petroleum ether extract in the tobacco leaves for the test group decreased by 12.4% under the impact of the medium. 4) After fermentation, the relative content of saturated fatty acids for the control group and the test group all increased, while the relative content of unsaturated fatty acids all decreased. 5) After the addition of the medium, the diversity of bacteria on tobacco leaves changed significantly, the number of OTUs in tobacco leaves increased, and the bacterial community structure changed. This research indicates that after adding the medium to ferment cigar filler, the changes of bacterial community and dominant bacterial group on cigar tobacco leaves have impacts on the contents of chemical components in tobacco leaves, and the fermentation with the addition of medium has a positive effect on improving the quality of tobacco leaves.

Quantitative Analysis of Routine Chemical Constituents of Tobacco Based on Thermogravimetric Analysis.

As the most basic indexes to evaluate the quality of tobacco, the contents of routine chemical constituents in tobacco are mainly detected by continuous-flow analysis at present. However, this method suffers from complex operation, time consumption, and environmental pollution. Thus, it is necessary to establish a rapid accurate detection method. Herein, different from the ongoing research studies that mainly chose near-infrared spectroscopy as the information source for quantitative analysis of chemical components in tobacco, we proposed for the first time to use the thermogravimetric (TG) curve to characterize the chemical composition of tobacco. The quantitative analysis models of six routine chemical constituents in tobacco, including total sugar, reducing sugar, total nitrogen, total alkaloids, chlorine, and potassium, were established by the combination of TG curve and partial least squares algorithm. The accuracy of the model was confirmed by the value of root mean square error for prediction. The models can be used for the rapid accurate analysis of compound contents. Moreover, we performed an in-depth analysis of the chemical mechanism revealed by the result of the quantitative model, namely, the regression coefficient, which reflected the correlation degree between the six chemicals and different stages of the tobacco thermal decomposition process.

ED01.02 Tobacco Carcinogens and Lung Cancer Susceptibility

ED01.02 Tobacco Carcinogens and Lung Cancer Susceptibility

Study on the Effect of Cut Tobacco Drying on the Pyrolysis and Combustion Properties

In order to establish the effect of cut tobacco drying on the subsequent pyrolysis and combustion properties, an oven drying method was applied to the treatment of the cut tobacco samples in a temperature range from 70 to 170°C. Thermogravimetric analysis was used to study the weight loss behavior of the dried cut tobacco samples under N2 and air atmospheres. The routine chemical components in tobacco were also determined with standard methods. The results showed that oven drying prepared uniformly treated samples. Low-temperature drying (at 70 and 110°C) had little effect on the pyrolysis and combustion properties, but high-temperature drying (at 150 and 170°C) led to a considerable reduction of sugar while producing new components that are harder to decompose.

The Chemical Components of Tobacco and Tobacco Smoke

The Chemical Components of Tobacco and Tobacco Smoke

Book Review: The Chemical Components of Tobacco and Tobacco Smoke

Abstract This book is highly recommended as an indispensable reference source for tobacco and smoke chemists as well as other scientists involved in the study of tobacco and its products. The compilation of proper chemical names, common names, Chemical Abstract Service numbers (CAS No.), and structures is alone worth the purchase price.