Characterization of Flavor Profiles of Cigar Tobacco Leaves Grown in China via Headspace-Gas Chromatography-Ion Mobility Spectrometry Coupled with Multivariate Analysis and Sensory Evaluation.

Although cigar tobacco leaves (CTLs) have a high economic value, research regarding the flavor characteristics of CTLs is currently limited. A comprehensive study of the flavor characteristics of CTLs from different regions of China was conducted by identifying their volatile-flavor-containing compounds (VFCs) and flavors. The samples were analyzed via gas chromatography-ion mobility spectrometry (GC-IMS) and sensory evaluation. Results revealed considerable differences in the VFC contents of CTLs from different regions of China, suggesting that the VFLs of CTLs could be influenced by geographical origin. Mainly, phenols, pyrazines, and aldehydes were present in the CTLs from Sichuan. High contents of esters and pyrazines were present in the CTLs from Hubei, while esters were the major components of the CTLs from Hainan. Multivariate analysis results showed the effective differentiation of samples from different geographical origins based on the GC-IMS results. Sensory evaluation revealed that the flavors of CTLs from different geographical origins were different. 1,8-Pinene, 3-methyl-3-butene-1-ol, 2,3-dimethyl-5-ethylpyrazine, 4-methyl-3-penten-2-one, and (E)-2-pentenal might serve as geographical marker compounds, indicating the geographical origin of CTLs based on the results of GC-IMS and sensory evaluation. This study may be beneficial for the trade of CTLs and the development of cigar products.

Detection of Phenotype-Related Mutations of COVID-19 via the Whole Genomic Data.

The coronavirus disease 2019 (COVID-19) epidemic continues to spread rapidly around the world and nearly 20 millions people are infected. This paper utilises both single-locus analysis and joint-SNPs analysis for detection of significant single nucleotide polymorphisms (SNPs) in the phenotypes of symptomatic versus asymptomatic, the early collection time versus the late collection time, the old versus the young, and the male versus the female. Also, this paper analyses the relationship between any two SNPs via linkage disequilibrium analysis, and visualises the patterns of cumulative mutations of SNPs over collection time. The results are in three folds. First, the SNP which locates at the nucleotide position 4321 is found to be an independent significant locus associated with all the first three phenotypes. Moreover, 12 significant SNPs are found in the first two studies. Second, gene orf1ab containing SNP-4321 is detected to be significantly associated with the first three phenotypes, and the three genes S, ORF3a, and N, are detected to be significant in the first two phenotypes. Third, some of the detected genes or SNPs are related to the SARS-COV-2 as supported by literature survey, which indicates that the results here may be helpful for further investigation.