CHEMICAL CONSTITUENTS IN HDBRG TOBACCO

Abstract

Harvel De Bouxo Rio Grande (HDBRG) tobacco is grown in the Guntur tract of Andhra Pradesh and is used in cigarette blends. The report that HDBRG tobacco is a rich source of solanesol has prompted to take up detailed investigations on the chemical quality parameters, lipophilic constituents and neutral volatile compounds responsible for flavour. HDBRG was found to be high in nicotine (2.9- 4.9%); low in reducing sugars (0.5 – 0.9%) and chlorides (0.2 – 0.3%). In respect of nutrient composition, the total nitrogen was high (2.9 – 3.8%), potassium was medium (0.7 – 1.7%) and phosphorus was low (~ 0.2%). Solanesol content in the samples varied from 1.60 to 2.80% with mean values of 1.97 and 2.46% for the seasons 2009-10 and 2010-11, respectively. Total hexane solubles or petroleum ether extractives (PEE) content in HDBRG tobacco was high (~ 10%) and solanesol accounted for ~ 25% of the extract. Further investigations were initiated for characterization of the non-polar and polar fractions which account for 5.8 – 8.3% and 1.1 – 2.1% of the hexane extract, respectively employing techniques like GC-MS and LC-MS. In the neutral volatile fraction, neophytadiene, megastigmatrienone isomers, duvatrienediol, thunbergol, dibutylphthalate, solanone, (E,E)-farnesylacetone, 4- oxo-beta-isodamascol and phenylacetaldehyde accounted for ~96% of the compounds. Nerolidol (0.7%), rishitin (0.7%), neryl acetone (0. 5%), (12z)- abienol (0.3%), phenylethyl alcohol (0.3%), indole (0.2%), viridiflorol (0.2%), 3-hydroxysolavetivone (0.1%), â-damascone (0.03%) and 14-labdien-8-ol (0.05%) are the other important flavour compounds identified. It is inferred from the data that presence of higher levels of these compounds could be attributed to higher nitrogen and nicotine contents in HDBRG leaf thus indicating their positive impact on the smoke flavour.