Changes Of Quality Of Flue-cured Tobacco In Different Relative Humidity During Aging

Aging treatment of tobacco is one of the most important processes of cigarette manufacturing. In this experiment, the relationship between relative humidity and chemical composition, physical property, appearance evaluation, sensory evaluation of flue-cured tobacco during aging were studied under conditions of constant temperature (22℃)and specific relative humidity(52%, 60%,68%). By doing so, the essay illustrate the effect of humidity of the ambient air on the quality of aged tobacco. The main results are as follow:1. During aging process, the appearance of tobacco improves to certain extent. Medium humidity (60%)is the optimum condition to improve the color and color intensity, then is the low humidity. Whereas high humidity is the ideal condition to improve the composition of upper leaves & cutters, the body and the oil of the upper leaves, then is the medium humidity. The effect of humidity on maturity of the tabocco varies from different places of production and different parts of the leaves.2. When we extent the aging duration, the equilibrium moisture decreases but the filling power goes up. The equilibrium moisture and the filling power of middle leaves enhance with the increase of the air humidity.3. During aging process, starch & total sugar content and nicotine value go down but the reducing sugar & polyphenol content goes up. High humidity is helpful to the degradation of the starch and total sugar and the nicotine of the lower leaves. The effect of humidity on total nitrogen content varies from different places of production and different part of the leaves. The polyphenol content in cutters decrease when the air humidity goes up.4. By evaluate the tobacco which has gone through 6 month of aging treatment, we get to know that high humidity does good to the improvement of the aroma quality and aroma amount, after taste , offensive odor and irritation property. Air humidity seldom has influence on the combustibility and ash color but do has minor influence on physiological strength and the concentration of the taste. As to the general evaluation of tobacco from different places of production, the 60% treatment is the most favorable humidity for the upper leaves of tobacco produced in Guizhou, the 68% treatment is for that produced in Shandong. The 68% treatment is the most favorable for the cutters from Guizhou, and the 52% treatment for that from Shandong. For lower leaves, the 68% treatment is the optimum humidity for both the tobacco from Guizhou and Shandong.