Analyses of Bright and Burley Tobacco Laminae and Stems

One sample each of aged uncased, cured bright lamina, bright stems, Burley lamina and Burley stems were examined by a variety of general analytical methods and then characterized by our standard fractionation procedure. These tobacco samples were chosen to be reasonably representative of the tobaccos used in current commercial cigarette products. Although for a given variety of tobacco the concentrations of chemical constituents may vary as a function of stalk position, cultural management, geographic origin or crop year, we believe that the following conclusions based on these samples are generally valid: [1] levels of ethanol solubles, total reducing sugars and starch are much higher in bright than in Burley, [2] concentrations of soluble ammonia and nitrate are greater in Burley than in bright, [3] total alkaloid and protein concentrations are higher in lamina than in stems, [4] cellulose, potassium and chloride concentrations are much greater in stems than in lamina, [5] concentrations of pectin, lignin and soluble hemicellulose do not vary greatly from one type of tobacco to another, [6] Burley lamina has greater concentrations of protein and acid detergent solubles than do the other types of tobaccos, and [7] bright lamina has a much lower level of total ash than do the other types of tobaccos. An examination of some of the components in ash led to the following conclusions: [1] total ash values are reasonable relative indicators of the level of non-nitrate inorganics, [2] a good estimate of the total contents of potassium, calcium, chloride, sulfate, phosphorus, silicon and magnesium may be obtained by multiplying the total ash value by 0.612, and [3] it is likely that most of the potassium and calcium in total ash is actually present as carbonates rather than oxides. The significantly higher levels of both protein and acid detergent solubles found in Burley lamina are thought to indicate that this protein may be unique in terms of its carbohydrate content or in terms of the nature or extent of its cross linkage.