Method for improving quality of tobacco leaves by adding enzyme preparation, glucose and citric acid

The invention provides a method for improving quality of tobacco leaves by adding enzyme preparation, glucose and citric acid and belongs to the field of tobacco processing. The method includes: spraying, by weight of that of treated tobacco leaves, 0.05%-0.1% of xylanase solution (pH=8.0) onto surfaces of the tobacco leaves prior to placing the tobacco leaves at the temperature ranging from 55 DEG C to 60 DEG C and the humidity of 50-60% in an enclosed environment for 4-10 hours; then spraying, by weight of that of the treated tobacco leaves, 0.1%-0.4% of acid protease solution (pH=3.5) onto the surfaces of the tobacco leaves and subjecting the tobacco leaves to stored-leaves enzymolysis for 3-6 hours at the temperature ranging from 20 DEG C to 30 DEG C and the humidity of 50-60%; adding, by weight of that of the treated tobacco leaves, 2.0%-4.0% of the glucose and 0.5%-1.0% of the citric acid for leaves storage for 5-8 hours in an environment at the temperature ranging from 20 DEG C to 30 DEG C and the humidity of 50-60%, drying the tobacco leaves for 3-10 minutes at the temperature ranging from 110 DEG C to 150 DEG C, and keeping flowing of air and turning of the tobacco leaves to further remove offensive odor and stimulus in the low-grade raw tobacco leaves; placing the well-treated tobacco leaves in an environment of a constant temperature and humidity chamber 22 DEG C in temperature and 60% in humidity for balancing for more than 48 hours till moisture content is equilibrium to 12%, and shredding prior to packing the tobacco leaves. By the method, tobacco smoke strength, the stimulus and the offensive odor can be lowered, pureness and mildness can be enhanced, and aroma can be harmonized.