Moisture Permeability of Cured Tobacco Epidermis

Abstract

The mechanism of moisture transfer into the cured tobacco leaf was investigated in connection with the moistening processes during cigarette manufacturing. The moisture was sorbed through three pathways: through the upper epidermis, lower epidermis and the cut face. For laminar tobacco larger than about 5.0 mm in width, most moisture was sorbed through the epidermes, with nearly equal flux through the upper and lower epidermes. The permeability of the culticular layer was the limiting factor to moisture transfer rate into the cured laminar tobacco through the epidermis, and the moisture transfer through the stomata was negligible as compared with that through the cuticular layer. An empirical kinetic model is presented to describe the entire moisture sorption process through cured tobacco epidermis, together with the values of the parameters involved. Rational moisture control of the cured laminar tobacco will be possible on the basis of this analysis.