- Détails du magazine
- Format
- Magazine
- eISSN
- 2719-9509
- Première publication
- 01 Jan 1992
- Période de publication
- 4 fois par an
- Langues
- Anglais
Chercher
Résumé
- Accès libre
Mainstream Smoke Chemistry and in Vitro and In Vivo Toxicity of the Reference Cigarettes 3R4F and 2R4F
Pages: 316 - 335
Résumé
A new reference cigarette, the 3R4F, has been developed to replace the depleting supply of the 2R4F cigarette. The present study was designed to compare mainstream smoke chemistry and toxicity of the two reference cigarettes under the International Organization for Standardization (ISO) machine smoking conditions, and to further compare mainstream smoke chemistry and toxicological activity of the 3R4F cigarette by two different smoking regimens, i.e., the machine smoking conditions specified by ISO and the Health Canada intensive (HCI) smoking conditions.
The
- Accès libre
Nitrogen Fertilization for Optimizing the Quality and Yield of Shade Grown Cuban Cigar Tobacco: Required Nitrogen Amounts, Application Schedules, Adequate Leaf Nitrogen Levels, and Early Season Diagnostic Tests
Pages: 336 - 349
Résumé
Nitrogen (N) fertilizers have a decisive influence on the yield and quality of tobacco. Yield, percentage of plant N, wrapper leaf quality, and nicotine content are all important quality characteristics in tobacco growing. This work is an attempt to provide a tool for optimizing mineral N nutrition for Cuban cigar tobacco, using a strategy that links N supply with leaf N concentration and wrapper yield. Similar approaches developed worldwide have mainly involved Virginia and Burley tobacco types but not Cuban cigar tobacco. The objective of the current work is to identify the effects of fertilizer N levels and timing of application on each of the mentioned quality factors for shade grown Cuban cigar tobacco. Another purpose is to explore the usefulness of a quick method of assessing the N status of plants based on measuring leaf transmission at two different wavelengths (650 and 940 nm). The experiments were done in the main tobacco growing area of Cuba (Vueltabajo). In each experiment, nine separate treatments were used covering different levels and times of fertilizer N application. The same experiment was carried out in three different years (2005-2006, 2006-2007, 2007-2008) but as the results were similar only one set of data is described (2006-2007). The patterns of response to N fertilizer of all four quality measurements, including yield and wrapper leaf quality, were similar in the different replications of the experiments. The optimal fertilizer level was 140-190 kg N/ha (40% applied on days 8-10 after transplanting and 60% on days 18-20 after transplanting). The optimal N concentration of leaves taken at the central foliar level of the middle stalk position was 4.3-4.7% at harvest time. Leaf transmission measurements by means of the SPAD-502 Chlorophyll Meter in the early stages of growth were correlated with leaf chlorophyll and N concentration and provide an excellent guide for predicting Cuban cigar tobacco wrapper leaf yield.
- Accès libre
Headspace Volumetric Karl Fischer Titration for the Determination of Water Content in Finished Tobacco Products
Pages: 350 - 359
Résumé
Because many physicochemical properties of tobacco are highly sensitive to its moisture content, the determination of water level is an important parameter for tobacco characterization. A headspace volumetric Karl Fischer titration (HS-V-KFT) method is presented for the quantification of water content in different finished tobacco materials. The parameters affecting the extraction of water from the tobacco materials were the sample size and the oven temperature which have been optimized. The extraction of water from the samples was achieved within a reasonable time (<25 min) with a sample size of 200 mg and an optimum temperature of between 90 °C and 100 °C. The results of the water determination by HS-V-KFT at the optimized parameters were in good agreement with those obtained by standard volumetric Karl Fischer titration. HS-V-KFT showed very good repeatability (RSDr 0.9%) and intermediate precision (RSDiR 1.1%). With respect to a considerable time saving, solvent consumption reduction, precision and accuracy, HS-V-KFT can therefore be suggested as the method of choice to determine water amount in finished tobacco products.