Relationship Between Tissue Structure of Tobacco Shreds and Equilibrium Moisture Content Thereof

To Study the relationship between tissue structure of cut shreds and moisture retentivity thereof,the surface and sectional structures of flue-cured,burley and oriental tobacco shreds were observed by a scanning electron microscope,the stomas of under epidermis were observed by an optical microscope,and the capillary specific surface area was measured by a specific surface area tester.The results showed that:1) The structure of oriental tobacco was the closest and its section was of porous structure,the section of domestic and Zimbabwean flue-cured tobacco was opener.2) The stoma number of burley tobacco was higher than that of flue-cured tobacco,while lower than that of oriental tobacco.The stalk positions of flue-cured tobacco of the same variety in the order of specific surface area were middle >lower >upper.3) The tissue structure positively correlated to equilibrium moisture content of tobacco shreds in low humidity(RH=30%) environment,while their correlation became negative in high humidity environment(RH=60%);and the influence of surface chemical composition in tobacco shreds on moisture content increased gradually with the rise of relative humidity.