The invention provides a method for improving the quality of expanded
cut rolled stem of tobacco by microbial
enzyme. The procedures are as follows:1) Preparation of bio-
enzyme: (1)
Aspergillus niger is activated and cultured by potato
cane sugar culture medium and is then transferred into sterilized seed culture medium, and shake cultivation is carried out at the temperature of 28 DEG C for 24 hours with 250r / min<-1>; seed liquid with 10% of
inoculation amount is transferred into a sterilized 500ml
shake flask (containing 100ml culture liquid for
enzyme), and the seed liquid carries out incubation for culturing at the temperature of 25 DEG C for 96 hours and then zymotic liquid is obtained. (2) Extraction of
lignin degradation complex enzyme: After being filtered by
filter paper, the zymotic liquid is centrifugally separated at the
low speed of 1500rpm. The supernatant carries out fractional
salting out by (NH4)2SO4 till the saturation is 0.7 to obtain crude enzyme liquid, after the crude enzyme liquid carries out
ultrafiltration dialysis, the
lignin degradation complex enzyme is obtained. Activities of enzyme components: 350U / L of Lip, 11U / L of MnP and 5.6U / L of Lac; 2) Improvement of the quality of expanded
cut rolled stem of tobacco: The expanded
cut rolled stem for cigarette is weighed and sprayed evenly by
lignin degradation complex enzyme liquid containing 0.2-0.4% of expanded cut rolled stem after being diluted by
distilled water at the temperature of 27 DEG C-29 DEG C. The expanded cut rolled stem of tobacco is placed in a sealed container for enzymolysis for 95-97 hours and dried naturally till the
moisture content is 12.5%-15%. The result by subjective analysis suggests that the complex enzyme preparation can effectively decrease the lignin content of the expanded cut rolled stem, promote the transformation of
aroma matter and improve
aroma quality and taste.