NEUTRAL VOLATILE COMPOUNDS IN ORIENTAL TOBACCO GROWN IN INDIA

Abstract

Oriental tobacco also known as ‘Turkish tobacco’ or ‘Aromatic tobacco’ possesses typical aromatic smoking quality characterized by sweet and sour taste. The present study was taken up with the objective of assessing the status of neutral volatile compounds (NVCs) in Oriental tobacco grown in the Kurnool tract of Andhra Pradesh. Gas chromatograph-Mass spectrometry (GC-MS) analysis was carried out in the neutral fraction of steam volatiles and 89 NVCs were identified in the samples analysed. The NVCs were classified into eight groups viz., norterpenoids (17%), norlabdanoids (2%), norcarotenoids (9%), cembranoids & thunberganoids (47%), neophytadiene (21%), Maillard reaction products (0.6%), phenylalanine related compounds (1.4%) and carbonyls, alcohols & esters (2%) thus accounting for ~99% of the NVCs identified. Norterpenoids, norlabdanoids and neophytadiene increased by 42, 100 and 31%, respectively in the samples from bottom to top positions on the stalk while cembranoids & thunberganoids decreased by 32%. There was no perceptible variation in the norcarotenoids among the leaf positions. The correlations observed were in tune with the increase of relative proportions in the case of norterpenoids, norlabdanoids and neophytadiene and decrease in the case of cembranoids & thunberganoids from bottom to top position of the plant. Neophytadiene, â-4,8,13-duvatriene-1,3diol, thunbergol, solanone, epiglobulol, norsolanadione, isomers of megastigmatrienones, (1s,2E,4s,5R,7E,11E)-cembra-2,7,11-trien-4,5-diol, farnesyl acetone, â-damascone, hexahydrothunbergol, 8,13-epoxylabd-14-en-12-one, 8-epoxy12-norambreinolide, (cis-A/B)-sclareoloxide and sclaral were identified as the important NVCs constituting the volatile profile of Oriental tobacco and their impact on the smoke flavour was documented. Identification of norlabdanoids viz., 8,13-epoxylabd-14-en-12-one, 8-epoxy-12norambreinolide, (cis-A/B)-sclareoloxide, sclareolide and sclaral in the Oriental tobacco samples analysed in the present study is an important finding as these compounds are responsible for the typical cedar-amber notes of this tobacco.