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Détails du magazine
Format
Magazine
eISSN
2719-9509
Première publication
01 Jan 1992
Période de publication
4 fois par an
Langues
Anglais

Chercher

Volume 13 (1985): Edition 2 (December 1985)

Détails du magazine
Format
Magazine
eISSN
2719-9509
Première publication
01 Jan 1992
Période de publication
4 fois par an
Langues
Anglais

Chercher

6 Articles
Accès libre

Neutron Activation Analysis in Tobacco and Cigarette Smoke Studies: 2R1 Cigarette Composition, Smoke Transference and Butt Filtration

Publié en ligne: 06 Jan 2015
Pages: 59 - 65

Résumé

Abstract

Presented are the results from the use of neutron activation analyses to determine some of the inorganic components of the complete 2R1 reference cigarette, the tobacco filler, the cigarette paper, the dropped ash and the mainstream particulate smoke. Transference values are given for Na, K, Br, Cl, Co, Rb, Al, Sc and Mn. Neutron activation analyses were used to determine butt filtration of selected inorganics in the tobacco rod and in cellulose acetate filters. Butt filtration curves for each 5 mm section behind the cigarette coal were constructed from the data. Na, K, Br and Cl appeared to be removed by normal filtration mechanisms (direct impaction, interception, or diffusion) of entrained particles of inorganic residue coming from the cigarette coal. Vapour condensation of the inorganics studied was not considered a major filtration mechanism because a uniform filtration was observed at distances far enough behind the coal that the smoke would have been at room temperature with essentially all condensation completed. Calcium and magnesium were shown to be removed in such a manner as to indicate a removal mechanism dependent on very large particles enriched in these elements. A proposed mechanism is given to account for the lack of any detectable transference of these elements to mainstream smoke.

Accès libre

A Comparison between the Rate of Reaction of Nitric Oxide in the Gas Phase and in Whole Cigarette Smoke

Publié en ligne: 06 Jan 2015
Pages: 67 - 73

Résumé

Abstract

There remains uncertainty about the rate of oxidation of nitric oxide (NO) in cigarette smoke. Using a single-port smoking machine and a chemiluminescence NO analyser we have investigated the rate of NO disappearance during cigarette smoke ageing over 10 minutes for gas phase and whole smoke. The disappearance of NO in whole smoke conformed to the (pseudo) second order kinetics observed for oxidation of NO in air. In the gas phase however the rate of disappearance was more rapid and appeared to follow first order kinetics. The possible mechanisms for this difference in behaviour are discussed.

Accès libre

The Rapid Pyrolytic Characterization of Tobacco Leaf Carbohydrate Material

Publié en ligne: 06 Jan 2015
Pages: 74 - 80

Résumé

Abstract

A rapid, semi-micropyrolysis technique was developed and applied to materials representative of tobacco cell-wall constituents and sucrose. Glass capillary gas chromatography - mass spectrometry was used to separate and identify the major semi-volatile pyrolyzate components. Cellulose and dextrin produced a pattern of furan and cyclic ketones of potential importance to flavour and aroma of tobacco smoke. Sucrose pyrolysis resulted in the formation of substantial amounts of 2-furaldehyde and lesser quantities of substituted furans. The cell-wall biopolymer lignin was a source of phenols, but contributed little to the compounds produced in the thermal breakdown of carbohydrates.

Accès libre

Effect of Cigarette Circumference on Formation Rates of Various Components in Mainstream Smoke

Publié en ligne: 06 Jan 2015
Pages: 81 - 87

Résumé

Abstract

Using cigarettes of different circumference but a constant packing density, the effect of circumference on the rate of formation (ratio of total delivery to the weight loss of tobacco during puffs) of various components was investigated. The rates of formation of CO and HCN increased and that of B[a]P decreased with decreasing circumference, while those of CO2, NO and vapour phase CH3CHO were independent of circumference. The differences in the effect of circumference on the rate of formation of CO, B[a]P and HCN can be explained by differences in their thermal formation during puffs.

Accès libre

Influence of Genetic and Cultural Factors on Chemical and Physical Properties of Tobacco: II. Cell Wall Biopolymers

Publié en ligne: 06 Jan 2015
Pages: 88 - 94

Résumé

Abstract

The influence of genetic factors and cultural management conditions on the cell wall biopolymer composition of tobacco was investigated. Five tobacco cultivars - Pennbel 69 (cigar filler), Catterton (Maryland), Coker 319 (bright), Burley 21 (Burley), and Little Sweet Orinoco (sun-cured) - were grown and cured under both flue-cured and dark fire-cured cultural management systems. The cell wall biopolymer composition of both freeze-dried mature (ripe) leaf and cured tobacco samples was determined by our standard fractionation procedure. For all five tobacco cultivars the levels of most cell wall biopolymers in the freeze-dried mature leaf did not vary significantly as a function of cultural management conditions. However, for Pennbel 69, Catterton and Coker 319 changing from flue-cured to dark fire-cured growing conditions relatively lowered starch contents by values between 32 % and 74 % while increasing the quantities of ethanol solubles and protein. The following general trends were noted for changes in chemical composition as a function of curing: protein decreased, lignin increased, soluble ash decreased and insoluble ash increased. Coker 319 and Little Sweet Orinoco were found to be generally lower in pectin, lignin, and cellulose than the other cultivars regardless of cultural regime.

Accès libre

Factors Effecting Discolouration and Carbonization of Unmanufactured Flue-cured Tobacco

Publié en ligne: 06 Jan 2015
Pages: 95 - 99

Résumé

Abstract

Modern advances in the mechanical processing of unmanufactured tobacco have developed conditions which could be favourable for the discolouration, carbonization, and possible pyrogenic reaction of flue-cured tobacco. Severe carbonization has been found in flue-cured tobaccos with moisture, packed temperature, and packed densities as low as 11 %, 40°C, and 370 kg / m3 respectively, and sugar contents as low as 14 % (moisture-free basis). We have focused our investigation on the redrying, prizing, and storage processes. The parameters chosen for this study included moisture content, packed temperature and packed density, and the insulative effects of packing containers as well as the effect of row position in storage. Data from the redrying and prizing processes were recorded for each container of tobacco. The tobacco temperature was monitored every four hours for the first 72 hours after packing and periodically thereafter when conditions so indicated. Samples for colour comparison and chemical analysis were taken at the beginning of each test, after 72 hours in storage and later as necessary. Key factors identified were packed density, moisture content and sustained internal temperature. A model for carbonization is proposed and an extension is made for the pyrogenic reaction.

6 Articles
Accès libre

Neutron Activation Analysis in Tobacco and Cigarette Smoke Studies: 2R1 Cigarette Composition, Smoke Transference and Butt Filtration

Publié en ligne: 06 Jan 2015
Pages: 59 - 65

Résumé

Abstract

Presented are the results from the use of neutron activation analyses to determine some of the inorganic components of the complete 2R1 reference cigarette, the tobacco filler, the cigarette paper, the dropped ash and the mainstream particulate smoke. Transference values are given for Na, K, Br, Cl, Co, Rb, Al, Sc and Mn. Neutron activation analyses were used to determine butt filtration of selected inorganics in the tobacco rod and in cellulose acetate filters. Butt filtration curves for each 5 mm section behind the cigarette coal were constructed from the data. Na, K, Br and Cl appeared to be removed by normal filtration mechanisms (direct impaction, interception, or diffusion) of entrained particles of inorganic residue coming from the cigarette coal. Vapour condensation of the inorganics studied was not considered a major filtration mechanism because a uniform filtration was observed at distances far enough behind the coal that the smoke would have been at room temperature with essentially all condensation completed. Calcium and magnesium were shown to be removed in such a manner as to indicate a removal mechanism dependent on very large particles enriched in these elements. A proposed mechanism is given to account for the lack of any detectable transference of these elements to mainstream smoke.

Accès libre

A Comparison between the Rate of Reaction of Nitric Oxide in the Gas Phase and in Whole Cigarette Smoke

Publié en ligne: 06 Jan 2015
Pages: 67 - 73

Résumé

Abstract

There remains uncertainty about the rate of oxidation of nitric oxide (NO) in cigarette smoke. Using a single-port smoking machine and a chemiluminescence NO analyser we have investigated the rate of NO disappearance during cigarette smoke ageing over 10 minutes for gas phase and whole smoke. The disappearance of NO in whole smoke conformed to the (pseudo) second order kinetics observed for oxidation of NO in air. In the gas phase however the rate of disappearance was more rapid and appeared to follow first order kinetics. The possible mechanisms for this difference in behaviour are discussed.

Accès libre

The Rapid Pyrolytic Characterization of Tobacco Leaf Carbohydrate Material

Publié en ligne: 06 Jan 2015
Pages: 74 - 80

Résumé

Abstract

A rapid, semi-micropyrolysis technique was developed and applied to materials representative of tobacco cell-wall constituents and sucrose. Glass capillary gas chromatography - mass spectrometry was used to separate and identify the major semi-volatile pyrolyzate components. Cellulose and dextrin produced a pattern of furan and cyclic ketones of potential importance to flavour and aroma of tobacco smoke. Sucrose pyrolysis resulted in the formation of substantial amounts of 2-furaldehyde and lesser quantities of substituted furans. The cell-wall biopolymer lignin was a source of phenols, but contributed little to the compounds produced in the thermal breakdown of carbohydrates.

Accès libre

Effect of Cigarette Circumference on Formation Rates of Various Components in Mainstream Smoke

Publié en ligne: 06 Jan 2015
Pages: 81 - 87

Résumé

Abstract

Using cigarettes of different circumference but a constant packing density, the effect of circumference on the rate of formation (ratio of total delivery to the weight loss of tobacco during puffs) of various components was investigated. The rates of formation of CO and HCN increased and that of B[a]P decreased with decreasing circumference, while those of CO2, NO and vapour phase CH3CHO were independent of circumference. The differences in the effect of circumference on the rate of formation of CO, B[a]P and HCN can be explained by differences in their thermal formation during puffs.

Accès libre

Influence of Genetic and Cultural Factors on Chemical and Physical Properties of Tobacco: II. Cell Wall Biopolymers

Publié en ligne: 06 Jan 2015
Pages: 88 - 94

Résumé

Abstract

The influence of genetic factors and cultural management conditions on the cell wall biopolymer composition of tobacco was investigated. Five tobacco cultivars - Pennbel 69 (cigar filler), Catterton (Maryland), Coker 319 (bright), Burley 21 (Burley), and Little Sweet Orinoco (sun-cured) - were grown and cured under both flue-cured and dark fire-cured cultural management systems. The cell wall biopolymer composition of both freeze-dried mature (ripe) leaf and cured tobacco samples was determined by our standard fractionation procedure. For all five tobacco cultivars the levels of most cell wall biopolymers in the freeze-dried mature leaf did not vary significantly as a function of cultural management conditions. However, for Pennbel 69, Catterton and Coker 319 changing from flue-cured to dark fire-cured growing conditions relatively lowered starch contents by values between 32 % and 74 % while increasing the quantities of ethanol solubles and protein. The following general trends were noted for changes in chemical composition as a function of curing: protein decreased, lignin increased, soluble ash decreased and insoluble ash increased. Coker 319 and Little Sweet Orinoco were found to be generally lower in pectin, lignin, and cellulose than the other cultivars regardless of cultural regime.

Accès libre

Factors Effecting Discolouration and Carbonization of Unmanufactured Flue-cured Tobacco

Publié en ligne: 06 Jan 2015
Pages: 95 - 99

Résumé

Abstract

Modern advances in the mechanical processing of unmanufactured tobacco have developed conditions which could be favourable for the discolouration, carbonization, and possible pyrogenic reaction of flue-cured tobacco. Severe carbonization has been found in flue-cured tobaccos with moisture, packed temperature, and packed densities as low as 11 %, 40°C, and 370 kg / m3 respectively, and sugar contents as low as 14 % (moisture-free basis). We have focused our investigation on the redrying, prizing, and storage processes. The parameters chosen for this study included moisture content, packed temperature and packed density, and the insulative effects of packing containers as well as the effect of row position in storage. Data from the redrying and prizing processes were recorded for each container of tobacco. The tobacco temperature was monitored every four hours for the first 72 hours after packing and periodically thereafter when conditions so indicated. Samples for colour comparison and chemical analysis were taken at the beginning of each test, after 72 hours in storage and later as necessary. Key factors identified were packed density, moisture content and sustained internal temperature. A model for carbonization is proposed and an extension is made for the pyrogenic reaction.

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