Abstract
There was a clear difference between the apparent viscosity ηa of dispersed systems of the flue-cured tobacco and that of the air-cured tobacco. To clarify this difference, the influences of water-soluble compositions included in tobacco on ηa were examined about the systems of the flue-cured tobacco, the air-cured tobacco, and their residues treated with water, using a ram-type extruder. Since a part of water-soluble compositions of tobacco should be dissolved into the water, the concentration of the systems was expressed in terms of the ratio of weights of water and insoluble composition.
Sugars, the major part of the water-soluble compositions for the flue-cured tobacco, exhibited a large effect on ηa. ηa decreased with increase of sugar content in tobacco and also with addition of sugers to the systems. The influences of the sugars were evenly observed for two varieties of tobacco and their residues.
The extract of the flue-cured tobacco bore the viscosity about 13 times larger than that of water. However, as dispersion medium, the extract gave a dispersion with lower ηa than did water. On the other hand, the extract of the air-cured tobacco bore the viscosity about 3 times larger than water, and it gave a dispersion with ηa slightly higher than did water.
By decationizing treatment, the viscosity η of two extracts and the apparent viscosity ηa of dispersed systems in these extracts were both decreased. The decrease in ηa were remarkable in the systems of the extract of the air-cured tobacco.
There was little difference in chemical compositions between two tobaccos, after treatment with hot water. Some differences in ηa, however, was observed between systems of two residues with as yet unknown reason.
