Estimating the aroma glycosides in flue-cured tobacco by solid-phase extraction and gas chromatography-mass spectrometry: changes in the bound aroma profile during leaf maturity

Glycosidically bound aroma compounds in flue-cured tobacco were estimated by capillary gas chromatography-mass spectrometry (GC-MS). After a fast isolation of extracts obtained by HP-20 solid-phase extraction and methanol elution, glycosides were treated with enzymatic hydrolysis and trifluoroacetylation (TFA) before GC-MS analysis. A totall of 21 bound aglycones, mainly consisting of aliphatic alcohol, aromatic components, C-13-norisoprenoids, sesquiterpenoids and polyphenols, were identified by enzymatic hydrolysis. In addition, with the aid of enzymatic hydrolysis, 14 glucosides, one rutinoside and three vicianosides were identified by TFA derivatization. The three vicianosides were identified for the first time in flue-cured tobacco. The norisoprenoids group made up >40% of the total level of aglycons in ripe tobacco, followed by polyphenol and aromatic derivatives (27 and 19%, respectively). Generally, levels of bound compounds increased significantly and the content of total glycosides increased by 36% with maturation. Among the glycosides detected, 3-oxo--ionol-glucoside was the most sensitive to maturity and increased the maximum degree. Copyright (c) 2015 John Wiley & Sons, Ltd.