- Journal Details
- First Published
- 01 Jan 1992
- Publication timeframe
- 4 times per year
- Open Access
Human Smoking Behaviour in Comparison with Machine Smoking Methods: A Summary of the Five Papers Presented at the 1995 Meeting of the CORESTA Smoke and Technology Groups in Vienna
Page range: 131 - 140
During the last months there have been extensive discussions, particularly in the United States, whether and to what extent data obtained by machine smoking using standardized methods (e.g. ISO, FTC, Coresta) permit conclusions about the actual uptake of smoke constituents (nicotine, condensate, etc.) by a smoker. This topic was a major focus of interest at the meeting of the Coresta Smoke and Technology Group in Vienna from 10th to 14th September 1995. A total of five studies were presented, four of which compared smoke yields obtained by standard machine smoking with actual yields obtained by human smoking. The fifth study investigated the effect of alternative puffing regimens and filter vent blocking on “tar” and nicotine yields of cigarettes. This paper summarizes the essential findings of the five studies.
- Open Access
Intercept-Reactant Method for the Determination of Aromatic Amines in Mainstream Tobacco Smoke
Page range: 141 - 156
A method for the determination of aromatic amines in mainstream smoke of mechanically smoked cigarettes has been developed. The fast reaction of aromatic amines with other smoke constituents formed during the combustion process can be significantly reduced by the addition of an excess of p-toluidine to the acidic collecting solution. From this point the p-toluidine as intercept reactant immediately stabilizes the originally formed amines and results in high recovery rates. The method allows the gas chromatographic determination of aniline, o- and m-toluidine, 1- and 2-aminonaphthalene, 2- and 4-aminobiphenyl, 1-, 2- and 4-aminofluorene, 3-aminofluoranthene, 1-aminopyrene and 6-aminochrysene in the mainstream smoke of a single cigarette. d5-Aniline, d7-2-aminonaphthalene, d9-4-aminobiphenyl as well as fluoranthene and chrysene were used as internal standards. By this new method, 21 ng of 2-aminonaphthalene and about 3,6 ng of 4-aminobiphenyl have been detected in the mainstream smoke of a common blend filter cigarette. As expected, these contents were higher in cigarettes manufactured from alkaline tobacco.
- Open Access
The Regulation and Biochemical Action of Natural Fungicides in Tobacco
Page range: 157 - 170
The biochemical interactions between the tobacco plant and a fungal pathogen are complex and poorly understood. Upon infection, the fungus overcomes the natural defence mechanism of the host by the lytic activity of enzymes and by suppressing the hypersensitive reaction of N. tabacum. The ability of the tobacco plant to resist a fungal attack is based on macroscopic properties and the biosynthesis of natural fungicides. The physical and biochemical character of the leaf surface (e.g. trichome exudates, cuticular components) may prevent the fungus from entering the organism. Constitutive natural fungicides such as phenolics and terpenes operate as enzyme inhibitors, or impair the germination of the fungal spores. Newly synthesized polysaccharides of the cell wall of leaf cells may delay the penetration of the fungus. Lignification of the surrounding cells occurs to protect the healthy tissue against attack. Toxic substances created during the melanization process of the tobacco plant can destroy the fungal cells. Biosynthesis of natural fungicides, such as phytoalexins, pathogenesis-related proteins and proteinase inhibitors is induced by exogenous or endogenous elicitors. These active protection systems may interfere with the fungal metabolism. Phytoalexins and pathogenesis-related proteins are highly effective defence responses which offer a broad spectrum of variability and resistance against a fungal infection. New strategies for engineering crop protection are based on these defence systems.
- Open Access
Rapid Near Infra-red Reflectance Analysis (NIRA) of Mainstream Smoke Collected on Cambridge Filter Pads
Page range: 171 - 184
Near infra-red (NIR) reflectance spectroscopy has been used for rapidly and reproducibly measuring the NIR spectra of mainstream smoke collected on Cambridge filter pads and quantifying the chemical composition from the spectral data. This technique has four main advantages: speed, simplicity of sample preparation, multiple analytes from one scan of a sample, and non-destruction of the sample. The study has been conducted in our research laboratory to define the possible use of NIRA (Near Infra-red Reflectance Analysis) as an instrumental screening tool for analysing mainstream smoke collected on Cambridge Filter pads. A major advantage of this method is that it eliminates the use of dangerous chemicals such as cyanogen bromide or chloride involved with some standard assays. Using specific wavelengths, we are able to determine with acceptable accuracy water, nicotine and tar. Correlation coefficients of NIRA results compared with those obtained by standard methods are better than 0.9 for all analyses. NIRA cannot replace ISO standard methods, flow analysis or chromatography, but as a reliable screening analysis, it could reduce the routine work load by 80 %. These savings could be achieved by prescreening samples with NIRA and analysing only suspect samples by distillation or continuous flow analysis.
- Open Access
Trends in Tobacco Leaf Usability
Page range: 185 - 195
The farmers and the buyers are partners in the production and purchase of usable tobacco leaf for manufacture into products acceptable to the consumer. The blend in these products and their ultimate sales price in the market place alters over time. Both parties must continually be aware of, and react to, these changes, if they are to stay in business. The principles of leaf purchase with regard to selection of ideal subjective looks, particularly emphasizing colour, maturity and plant position, will not be radically changed, but they must be coupled with acceptable, objective chemical contents to ensure subsequent, accurate product blending and favourable smoking properties. High technology in cigarette manufacture also demands that the threshed product, after green leaf processing, notably particle size, objectionable stem, and stem in lamina, together with packing moisture and minimal foreign matter, must meet strict specifications. The growing, curing, marketing, and purchase of leaf, together with its green leaf processing and cigarette manufacture, have all become more objective in definition. Usability, in relation to all these factors, is therefore what is attractive to the buyer/manufacturer and ultimately to the consumer, but the actual inclusion of leaf in a particular product is also related to its price. Usability and price play a major role in leaf selection and these are discussed.