Relationship between Free Amino Acid Index and Burnt-Mellow-Sweet Aroma Style Intensity of Flue-Cured Tobacco Leaves

80 samples of flue-cured tobacco leaves in Ganzhou area, Jiangxi Province in China were selected, relationships between free amino acid index and burntmellow- sweet aroma style intensity of leaves were studied with correlation analysis and stepwise regression analysis. In contrast to the content of Trp, Ile, Ser, Cys, β-Ala, Lys and the ratio of β-AiBA/TFAA, the content of Asp, Ala, Gly, Leu, β-AiBA and the ratio of Trp/TFAA, Ile/TFAA, Val/TFAA, Thr/TFAA, Ser/TFAA, Cys/TFAA, Asn/TFAA, β-Ala/TFAA, Lys/TFAA and Pro/TFAA in fluecured tobacco leaves had extremely significant positive correlation with burntmellow- sweet aroma style intensity. There was a significant negative correlation between burnt-mellow-sweet aroma style intensity and the content of Phe, Tyr, Asn, γ-ABA. 31 free amino acid indexes including the content of Asp, Glu, Phe etc. and the ratio of Glu/TFAA, Phe/TFAA, Trp/TFAA, etc. were main free amino acid index influencing burnt-mellow-sweet aroma style intensity of flue-cured tobacco leaves, which jointly decides 99.1% of variation of burnt-mellow-sweet aroma style intensity.