Tobacco blend

The smoke analysis of cigarettes made from the same tobacco blend, but with and without filter tips revealed that cellulose acetate retains TSNA selectively (Table VIIl). This phenomenon is clearly established for a large number of filter cigarettes. 

Kessler DA, Wilkenfeld JP, Thompson LJ (1997). The Food and Drug Administration s rule on tobacco blending science and Law. Pediatrics 99(6) 884-887 Koop EC (2004) Tobacco the public health disaster of the twentieth century. In Boyle P, Gray N, Henningfield JE, Seffrin J, Zatonski W (eds) Tobacco and public health science and policy. Oxford University Press, Oxford, UK, pp v-xvii... 

MSS from fonr tobacco types and a commercial tobacco blend was fonnd with carbon chain lengths equal to or less than C24 only trace amonnts of alkanes at or below n-hexadecane were fonnd by Spears et al. (3768). They also reported that nearly 48% of an alkene-free alkane fraction (0.75 mg/cig) from MSS consisted of n-hentriacontane (0.182 mg/cig), n-dotriacontane (0.108 mg/cig), and n-tritriacontane (0.069 mg/cig). 

Rodgman et al. (3294) described the composition of an aliphatic ester fraction isolated from MSS generated by cigarettes fabricated from an American tobacco blend, burley tobacco, or Oriental tobacco. Aliphatic ester fractions almost identical with those from the smokes were also isolated from flue-cured tobacco, burley, and Oriental tobaccos. With the analytical technology available in the early 1960s, the aliphatic ester fraction was shown to consist of a series of esters whose alcohol moiety varied from 1-dodecanol (C12) to... 

Although much of the early research at RJRT R D on the identification of PAHs in MSS and the effect of various tobacco blends and/or treatments on their MSS yields was summarized in several recent publications (3262, 3307), other members of the U.S. tobacco industry were also much involved in similar research in the 1960s and 1970s. The following paragraphs provide a few examples of their early efforts. 

With regard to tobacco components, Lloyd et al. (2389) identified 275 previously unidentified components of additive-free flue-cured tobacco, 132 new to all additive-free tobacco types. Many of these compounds were highly polar and considered significant contributors to MSS flavor and aroma. Similar detailed studies were conducted on the composition of hurley tobacco by Roberts and Rohde (3219), Oriental tobacco by Schumacher and Vestal (3561), and Maryland tobacco by Schumacher (3550). Years later, it became apparent that many of the highly polar components of tobacco and tobacco smoke were identical with similar to many of the components used in the flavor formulations, that is, the top dressing, added to a specific tobacco blend to impart its unique smoking characteristics (1053). Randomly selected publications on the identification of many additive-free tobacco and/or tobacco smoke components are listed in Table II.A-2. 

It is interesting to note that all bnt two (formic acid, octa-decanoic acid [stearic acid]) of the MSS vapor-phase and particnlate-phase acids discussed above—whether identified in tobacco, tobacco smoke, or both—are listed by Doull et al. (1053) as compounds included in the flavor formulations added to a tobacco blend by U.S. cigarette manufacturers to enhance consumer acceptability of the product. 

Amino acids, both as free acids and as acids bound within protein molecules, are present in all of the tobacco types (flue-cured, burley, Oriental, Maryland) used in the American tobacco blend. 

C-coumarin applied to the tobacco blend, Newell reported that 60% appeared unchanged in the MSS and SSS. 

Hecht et al. (1562) described the importance of 1,2-benzenediol (catechol) as a tobacco smoke cocarcinogen. They also noted that the levels of 1,2-benzenediol (catechol) in MSS was reduced by prior extraction of the tobacco with hexane-ethanol or by inclusion of reconstituted tobacco sheet (RTS) in the tobacco blend. 

At the same conference, Hoffmann and Wynder (1798) also discnssed the percent rednction of the PAH content, spe-cihcally the B[a]P content, of the cigarette CSC by inclnsion of RTS in the cigarette tobacco blend. Althongh analytical data on the decrease in TPM, B[a]P, and phenol yields were presented graphically, they had no comment on the signih-cant percent reduction in the phenol content of the MSS, a percent rednction that exceeded that of the B[a]P content. 

This suggestion, coupled with the mouse skin-painting bioassay results reported by Takizawa (3865a) that several simple quinones such as 2,5-cyclohexadiene-l,4-dione (p-benzoquinone), 1,2-naphthalenedione (1,2-naphthoquinone), and 1,4-naphthalenedione (1,4-naphthoquinone) were tumorigenic to mouse skin, raised serious questions about the desirability of adding phenols to the tobacco blend to enhance the odor and flavor of its smoke. Despite the many studies in which benzene was used as the solvent for testing of the tumorigenicity of PAHs, benzene seldom induced tumors in... 

Roberts commented that two particular pyridine compounds were noteworthy, 2-acetylpyridine [l-(2-pyridinyl)-ethanone] and 2-methyl-5-isopropylpyridine [2-methyl-5-(l-methylethyl)-pyridine] (3215). The former adds some sweet, roasted, and musty notes and the latter adds body and burley character to the tobacco blend. Additionally some pyridines may react with other smoke componnds synergistically. For example, it is believed that some pyridines rednce the sweet bnrnt-sngar taste of cyclopentenones and fnranones (3215). 

A study to determine the effect of different levels of added glycerol on cigarette MSS yields The glycerol transfer was proportional to that added to the tobacco blend. 

If it is assumed not only that the same type of reaction occurs in a cigarette during the smoking process in the case of compound X, either added iX to or inherent (X) in the tobacco blend, but also that similar degradation reactions occur with the other tobacco components (Xj, X, X3,. .. X ) the situation described in the following equations could exist, where n could be as high as or higher than 5300, the approximate number of identified tobacco components. 

Nicotine (as well as the other nicotine-related alkaloids in tobacco, usually present in trace amounts) is the one tobacco component whose level in tobacco is sometimes controlled by removal in a denicotinization process. In contrast to the removal or reduction of its level in the case of nicotine, materials such as simple sugars, glycerol, and some flavorants are added to the tobacco blend to augment their existing levels in the tobacco and to enhance certain consumer acceptable organoleptic properties of the MSS. Materials such as... 

The levels in MSS of TSNAs such as NNN can presumably be reduced by reduction in the level of nicotine and/or nitrate in the tobacco blend (499). However, Brunnemann et al. (511) have presented contradictory data on the significance of the correlations among the levels of nitrate, nicotine, and TSNAs in tobacco. 

From a precursor spiking experiment involving addition to tobacco of aliphatic tobacco hydrocarbons, a phytosterol (P-sitosterol), or solanesol, it was noted that the increase in the chrysene yield in the CSC was much more pronounced with phytosterol-treated tobacco than with aliphatic hydrocarbon-or solanesol-treated tobacco (3251, 3269, 3291). Doubling the levels of solanesol, aliphatic tobacco hydrocarbons, and phytosterols by addition of each to a control tobacco blend resulted in increases in the B[a]P yields in the mainstream CSCs of 13%, 13%, and 16%, respectively. However, the chrysene yields were increased by 16%, 28%, and 183%, respectively. Tripling the addition levels increased the B[a]P levels in the mainstream CSCs by 18%, 20%, and 28%, respectively, and the chrysene levels by 22%, 50%, and 239%, respectively. 

In 1958, Rodgman and Cook (3269, 3291) added tobacco-derived satnrated aliphatic hydrocarbons to a tobacco blend in a spiking experiment and determined the effect of the addition on the PAH levels in mainstream CSC. They reported the added saturated hydrocarbons increased the yield of PAHs in cigarette MSS and thus were precursors of the smoke PAHs. 

Fractions From University of Kentucky 1R1 Tobacco Blend (3616) ... 

Table XXV-11 summarizes pyrolysis data from Lam (2257), Gilbert and Lindsey (1289), and Severson et al. (3616) with particular emphasis on the somewhat similar experimental conditions (pyrolysis temperature, atmosphere) and on the yields of B[fl]P and B[c]P from the pyrolysis of different tobaccos, blend, components, and/or fractions.

Examination of these data indicates that the percent conversion of these structural components to phenol ranges from one (0.0013%) to about four (0.0036%) one-thousandths of a percent, whereas the conversion of these three components to benzo[fl]pyrene ranges from about one (0.0000014%) to about fourteen (0.0000136%) one-millionth of a percent. Such data may be used to estimate the conversion to PAHs and phenols of a flavorant (structurally similar to but of lower molecular weight and higher volatility than these biopolymers) added to the tobacco blend. 

Mainstream Smoke Delivery of PAH, jig/cig, at Trimyristin Addition Level to Tobacco Blend, mg/g... 

---