- Journal Details
- First Published
- 01 Jan 1992
- Publication timeframe
- 4 times per year
- Open Access
Page range: 1 - 10
Major components of cell wall materials, that is a-cellulose, hemicellulose, pectin and lignin, were isolated from tobacco leaves. They were heated in a micro-thermobalance in different atmospheres and at different heating rates. The weight loss rate of the sample materials, production rates of carbon oxides and smoke particles produced were measured. In general, materials which produce more carbon oxides produce less smoke particulate mass. In helium at a heating rate of 240°C/min, which attempts to approximate the burning conditions of a cigarette, weight ratios of smoke particles to the sample weight were 32 % for a-cellulose, 24 % for lignin, 3 % for hemicellulose and 0.4 % for pectin. Since a-cellulose is a major constituent of the cell wall of tobacco leaves and has the highest production rate, it can be concluded that a-cellulose is a major contributor to the production of smoke particles from cigarettes. On the contrary, pectin contributes the least.
- Open Access
The Determination of Benzo[a]Pyrene and Benz[a]Anthracene in Mainstream and Sidestream Smoke of the Kentucky Reference Cigarette 1R4F and a Cigarette Which Heats but Does Not Burn Tobacco: A Comparison
Page range: 11 - 17
A quantitative method for the determination of benz[a]anthracene (B[a]A) and benzo[a]pyrene (B[a]P) in mainstream and sidestream cigarette smoke by high performance liquid chromatography (HPLC) has been developed. Mainstream and sidestream particulate matter is collected on Cambridge filter pads. The polycyclic aromatic hydrocarbons (PAH) are extracted with cyclohexane and subjected to normal-phase chromatography to isolate target fractions which are concentrated and then diluted with acetonitrile or acetonitrile/water prior to reverse-phase analytical chromatography. The Kentucky Reference cigarette 1R4F and a cigarette which heats but does not burn tobacco (New Cigarette) developed at R.J. Reynolds Tobacco Company were analysed and compared with respect to B[a]P and B[a]A in both mainstream and sidestream smoke.
- Open Access
Heavy Metals in Tobacco Smoke II: Trace Metals Cadmium, Lead, Copper, Cobaltand Nickel in Austrian Cigarettesand in Particle Phase and Smoke Gas - Schwermetalle in Tabaken und in Tabakrauch ll: Spurenelemente Cadmium, Blei, Kupfer, Kobalt und Nickel in oesterreichischen Zigaretten und deren Rauchkondensaten und Rauchgasen
Page range: 19 - 32
The trace metals cadmium, lead, copper, cobalt and nickel have been analysed in 14 different Austrian filter cigarettes. The results show a good conformity thus allowing the calculation of a characteristic mean value. The same metals were analysed separately in the gas and particle phase. From this data and the results obtained from butt and ash analysis, the sidestream concentrations and the transfer rates for both fractions could be evaluated. A classification into light and heavy cigarettes on the basis of heavy metal contents could not be made due to the similarity of the results.
- Open Access
Tobacco Leaf Protein: I. An Evaluation of the Use of Putative Chemical Growth Enhancers for Tobacco Leaf Protein Production
Page range: 33 - 41
Effects of foliar applications of long-chain fatty compounds on production of leaf protein from tobacco genotypes were evaluated. Triacontanol, purported to be a growth stimulant, had minimal effects on most experimental parameters. A propriety product, AgroLizer™, appeared to exert greater influence but results were inconclusive. Chemical treatments interacted with environmental conditions and tobacco genotype. Acid precipitation of the green fraction resulted in a pellet that could be easily removed by low speed centrifugation but produced a white fraction with lower protein percentage than heat precipitation of the green fraction. Triacontanol delayed flowering and extended vegetative growth in some genotypes. Increased cured leaf yields of flue-cured and Maryland type tobaccos were consistent but not statistically significant. An important finding was discovery of a genotype, T.I. 401, that produced high amounts of extractable leaf protein regardless of growth stage. This variety became the object of a follow-up investigation.
- Open Access
Tobacco Leaf Protein: II. Genetic and Fractionation Approaches to Improving Tobacco Leaf Protein Production
Page range: 43 - 52
Tobacco variety T. I. 401 was evaluated for seasonal leaf protein yields and crossbred with other genotypes to determine whether leaf protein yield was a genetically transmissible trait. Relatively high leaf protein yields associated with later maturity were observed in preliminary trials but additional crossbreeding and selection is deemed necessary to achieve stable integration of improved leaf protein yields and desirable agronomic performance. Chromatographic and electrophoretic analyses demonstrated that high leaf protein yield of T. I. 401 was not associated with a particular protein fraction but rather was a general phenomenon affecting all major protein classes. Besides examining genetic factors for improving leaf protein yields, two mechanical improvements in leaf protein fractionation technology were introduced into the process. A mild acidification step (to pH 5.5) with a subsequent moderate heat treatment (50°C) resulted in a green coagulum which was readily removed by brief low speed centrifugation without substantial loss of the fraction containing soluble protein which precipitates as a white pellet when heated to 80°C. Hollow-fiber membrane technology was also investigated as a means of producing a purified concentrate with high levels of undegraded protein. The membrane system tested was relatively efficient and greatly improved the quality of the Protein product.