SUMMARYOne 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 cigll;l'ette productso 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, [

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.