Relationship among aroma type, aroma note and aroma components of flue cured tobacco in Hubei

【Objective】In order to provide data support for the production and supply of refined and diversified tobacco raw materials, the flavor characteristics of tobacco in Hubei were studied, the relationship between aroma type and aroma note, aroma components and other indicators was clarified, and the prediction model of tobacco aroma type was established.【Method】A total of 72 middle orange grade 3(C3F) flue-cured tobacco samples were collected from 18 counties(cities) in Enshi, Shiyan, Xiangyang and Yichang in Hubei.The aroma type, aroma note, aroma components and physicochemical indexes of the samples were evaluated and detected.The relevant data were statistically analyzed to establish a regression prediction model.【Result】Hubei flue-cured tobacco was intermediate aroma type, with hay fragrance, sweet fragrance, woody fragrance, burnt fragrance, green fragrance, spicy fragrance, light sweet fragrance, burnt sweet fragrance and resin fragrance, of which hay and positive sweet fragrance were the main aroma note.There were extremely significant differences(P< 0.01, the same below) in aroma types of tobacco leaves among different producing areas, and aroma notes including sweet fragrance, positive sweet fragrance, burnt fragrance and resin fragrance.According to the aroma type of tobacco leaves, it could be divided into Enshi, Yichang-typical mellow and sweet fragrance aroma areas, Shiyanmellow and sweet fragrance aroma area, Xiangyang-mellow and sweet fragrance aroma area.Simple correlation analysis showed that the significant(P< 0.05, the same below) or extremely significant positive correlation indexes with aroma types were hay fragrance, positive sweet fragrance, megastigmatrienone, isophorone, rabdosial, 10-undecanonal, phenylethanol, β-damascus, geranyl isobutyrate, while the significant or extremely significant negative correlation indexes were burnt sweet fragrance, resin fragrance, stem percentage and chlorine.Variance analysis showed that there were 25 kinds of aroma components and 4 kinds of chemical indexes that had significant difference.Through stepwise regression analysis, the linear regression equation between aroma types and 14 key aromas and chemical components was established:aroma type T=2.590+0.898×2-ethylhexyl alcohol-0.028×benzaldehyde-0.660×o-methylbenzaldehyde-0.020×saffron aldehyde+0.326×2-heptenenal+0.011×megastigmatrienone+0.001×3-methyl-2, 5-furandione+3.210×methylcyclopentenone-6.051×1, 4-cyclohexanedione+5.663×3-methyl-2(5H) furanone-4.075×methyl hexanoate-5.053×α-angelica lactone-0.141×reducing sugar+3.458×nitrogen-alkali ratio.【Conclusion】The results show that the aroma type of Hubei flue-cured tobacco is intermediate aroma type, with rich aroma, hay and positive sweet fragrance as the main aroma.The aroma characteristics of flue-cured tobacco in four main production areas are distinct.The linear regression equation of aroma types and the 14 aromas and chemical components key indexes was established by stepwise regression analysis.The regression model established can be used to predict the aroma type of tobacco leaves, which has important reference value for the production and development of refined and diversified tobacco raw materials.