NEUTRAL VOLATILE COMPOUNDS IN FCV TOBACCO

It is reported that about 41 compounds are found in substantial quantities to enable the smoker to perceive their impact on smoke flavour. With the objective of analysing neutral volatile compounds responsible for smoke flavour in FCV tobacco grown in Northern Light Soils (NLS), Karnataka Light Soils (KLS) & Southern Light Soils (SLS), steam volatile compounds were extracted and gas chromatography-mass spectrometry (GC-MS) analysis was carried out. As authentic standards of the compounds are not available for quantification, the area normalization method was adopted and the proportion of a particular compound in the total neutral volatile fraction was calculated. Composition of the neutral volatile fraction varied in tobacco samples from different agro-climatic zones. Higher proportion of neophytadiene (40.8%), megastigmatrienone isomers (10.1%), thunbergol (7.2%), 3hydroxysolavetivone (6.7%), solavetivone (4.6%) and duvatriendiol (4.1%) was observed in NLS samples. Neophytadiene (21.0%), dibutyl phthalate (21.5%), viridiflorol (13.9%), 3-hydroxysolavetivone (12.3%), 1-nonadecene (12.0%), thunbergol (11.3%), solavetivone (8.1%), cembrene (6.3%) and megastigmatrienone isomers (5.9%) were the important compounds in the fraction in KLS samples. These differences could be attributed to the climatic conditions and agronomic practices, the variety Kanchan being common. In the samples from SLS region, the proportion of neophytadiene (28.4%), thunbergol (23.5%), viridiflorol (17.2%), caryophyllene oxide (9.6%), duvatrienediol (9.2%) and megastigmatrienone isomers (8.9%) was high, thus implying the varietal effect, as Hema and Siri are predominantly cultivated in the region. Identification of compounds viz., rishitin, solavetivone, nerolidol, farnesol and linalool necessitates further investigations on their role in insect-pest management