Research On Starch And Protein Degradation Of Tobacco Leaves By Biological Technology

The feasibility of adding self-made microbe materials of tobacco to reduce starch and protein of tobacco leaves during flue-curing process and fermentation, and to improve aroma components of tobacco leaves was researched. The results were as follows:To improve activity of amylase and protease born of Bacillus subtilis, three steps were done. There were significant effects. The results showed that: Mg²⁺, k⁺ could increase the activity of α-amylase, glucose-amylase and neutral protease, We also found that when the concentration of Mg²⁺ were 0.8mg/ml, 1.2mg/ml and 1.2mg/ml, the activity of a-amylase, glucose-amylase and neutral protease had the best effects. k⁺ had the strongest effects at 1.0 mg/ml, 1.0 mg/ml and 0.8 mg/ml. Low concentration of Mn²⁺ could improve the α-amylase, glucose-amylase and neutral protease activities while high concentration of it inhibited their activities. Surface-active agent could enhance the activity of α-amylase by 6.83%. By comparing different culture mediums, we found the best medium for α-amylase consisted of 4.0% corn flour, 2.5 % soybean cake, 0.5% bran, 1% additive of tobacco, 0.1% K₂HPO₄, 0.05% MgSO₄, and 0.05% KCL. The best medium for glucose-amylase consisted of 4.0% corn flour, 3.0 % soybean cake, 1% additive of tobacco, 0.1% K₂HPO₄, 0.05% MgSO₄, and 0.05% KCL. The best medium for neutral protease consisted of 8.0% corn flour, 4.0 % soybean cake, 1% additive of tobacco, 0.4% (NH₄)₂SO₄, 0.5% pepton, 0.05% K₂HPO₄, and 0.08% Na₂HPO₄.During flue-curing process, self-made microbe materials of tobacco were applied to tobacco leaves in order to reduce starch and protein of tobacco leaves, which obtained good results. The results showed that: the content of starch and protein obviously could be decreased to 27.58%, 26.12% at most, and the content of total sugar and free amino acid increased. The result was significantly different with normal flue-curing process. Content of Starch decreased deeply with more α -amylase being applied in the range of zero and eighty, and the best effect could be achieved when the mixture of α -amylase, glucose-amylase and neutral protease was used. This showed that neutral protease could accelerate amylase's reducing starch. Protein and free amino acid are significantly different with normal flue-curing, protein content...