Tobacco
A Review by John C. Leffingwell, Ph.D.
This a part of our series on aroma materials produced by carotenoid degradation.
Undoubtedly due to health and social concerns, tobacco has been the most thoroughly researched natural product in history. We believe that well over U.S. 100 million dollars has been expended in the study of tobacco constituent composition. Over 2700 compounds have been identified in various tobacco varieties (Virginia, Burley and Oriental) and it is estimated that in excess of 6000 may be in tobacco smoke.
The study of tobacco constituents has identified seminal knowledge of importance to our understanding of plant constituents (e.g., identification and structural elucidation of the ubiquitous plant constituent, solanesol), the first identification of the class known as cembranoids, the finding that novel sugar esters in the leaf waxes act as both insect repellent and as the aroma precursor for Oriental tobacco, the discovery of 2-acetylpyrazine with its characteristic "popcorn" aroma, and especially to our knowledge of carotenoid degradation which is of importance to the flavor and aroma of many flowers and foodstuffs. In addition, our knowledge of genetic engineering was pioneered through use of the tobacco plant.
This review focuses solely on the aspect of potential aroma constituents produced by carotenoid degradation and does not touch on the many other classes of compounds in tobacco.
The following charts provide an overview of various aroma constituents produced in tobacco leaf via oxidative carotenoid degradation.
Aroma Properties of Selected Tobacco Carotenoid Derivatives
NameStructureAroma Properties
beta-Ionone
Woody, violet, fruity; woody-raspberry on dilutionalpha-Ionone
Woody balsamic, violet-raspberry in dilutionbeta-Damascone
Fruity (apple-citrus), tea-like with slight minty notebeta-Damascenone
Fruity, floral with apple, plum-raisen, tea, rose, tobacco noteOxo-Edulan I
Oriental Tobacco likeOxo-Edulan II
Oriental Tobacco likeTheaspirone
Tea like4-Oxo-beta-ionone
Sweet rich like Virginia tobacco3-Oxo-alpha-Ionone
Sweet, floralDihydroactinodiolide
Weak , slightly coolingSafanal
Saffron, green, sweet, hay-likebeta-Cyclocitral
Green, grassy hay like odorReferences