Analysis of Quality Characteristics and Metabolite Differences of Flue-Cured Tobacco Leaves of Main Sun-Cured Tobacco Varieties in Leshan City,Sichuan Province

JIN Dongmei; LI Chenxi; SHAO Jimin; LI Chaoyang; JIANG Tongyan; SUN Zhiqiang; ZHANG Qian; ZHANG Xiaoquan; CHEN Haiyang

doi:10.3969/j.issn.1003-4749.2026.03.002

Abstract：In order to clarify the quality characteristics and metabolite differences of the main air-cured tobacco varieties in Leshan County,Sichuan Province,Nie'er QING Qingmao(NQ)and Nie'er Qing Huangmao(NH)were used as test materials.After air-curing and fermentation,solid phase microextraction(SPME)combined with gas chromatography-mass spectrometry(GC-MS)was used to analyze totacco leaves appearance quality,physical properties,chemical composition and sensory quality,and to detect totacco leaves aroma components and metabolites.The results showed that the appearance quality of NQ tobacco leaves was better than that of NH,which was more in line with the evaluation criteria of high-quality air-cured tobacco.From the perspective of physical properties,the leaf weight,equilibrium moisture content and tensile strength of NH tobacco leaves were significantly higher than those of NQ,and the maximum leaf length,maximum leaf width,single leaf weight,leaf thickness and stem content were not significantly different from those of NQ.From the perspective of chemical composition,the total sugar content,reduced sugar content,nicotine content,chlorine content and potassium content of NH tobacco leaves were significantly higher than those of NQ,and the ratio of potassium to chlorine was significantly lower than that of NQ.From the perspective of sensory quality,the aroma level,comfort and sensory coordination of NH tobacco leaves were due to NQ.From the perspective of aroma components,the content of seven aroma substances in NH tobacco leaves was significantly higher than that of NQ,which were 6,10,14-trimethyl-2-pentadecanone,1-methyl-2-pyrrolidone,cotinine,(1'S,2'S)-nicotine-N'-oxide,hexamethylcyclotrisiloxane,1,2,3,6-tetrahydro-2,3'-bipyridine and 1-(3-pyridyl)ethanone.From the difference of metabolites,the contents of 8 metabolites in NH tobacco leaves were significantly higher than those in NQ,which were guanosine-5'-monophosphate,2-deoxyuridine-5'-monophosphate,L-cystathionine,γ-L-glutamyl-L-2-aminobutyric acid ester,isocitrate,L-tyrosine,L-glutamine and 5-deoxy-5-methylthioadenosine,respectively.The content of one metabolite was significantly lower than that of NQ,which was cytosine.In addition,KEGG enrichment results showed that the differential metabolites of NQ and NH tobacco leaves were significantly enriched in 20 pathways,which were closely related to plant nitrogen metabolism,energy metabolism and secondary metabolite synthesis.The results provide a theoretical basis for the selection of high-quality sun-cured tobacco varieties in Leshan City.