Study On The Quality Improvement Effect Of Microorganisms,Enzyme Preparations And Amino Acids On Tobacco Stem Extract

Reconstituted tobacco leaves have heavier smoke and miscellaneous gas,high irritation,low aroma content,and poor smoke softness.In order to improve the fermentation process of tobacco stem extract of the raw material of reconstituted tobacco leaves,this experiment screened and identified aroma-producing functional microorganisms from aged tobacco leaves,and pretreated the tobacco stem extract with enzymes,aroma producing functional microorganisms and amino acids so as to promote the degradation of unfavorable chemical components in tobacco stem extract and improve the smoking quality of reconstituted tobacco leaves.This study clarified the impact of different treatments on the quality of tobacco stem extract and reconstituted tobacco leaves,and provided technical and theoretical support for the application of exogenous enzymes,microorganisms and amino acids in the processing and production of reconstituted tobacco leaves.The main conclusions are as follows:(1)Two strains of A1 Bacillus and A2 Microbacteria were screened from the surface of aged tobacco leaves,which can effectively degrade macromolecular compounds and harmful precursors in tobacco leaves,and reduce impurities and irritation in tobacco leaves,and increase aroma components.(2)Response surface methodology was used to optimize the optimal conditions for enzymes,microorganisms and amino acids to improve the quality of reconstituted tobacco leaves,and the following results were obtained: 1)The optimal enzymatic hydrolysis process conditions for compound enzymes were: acid protease dosage was 74.12%,pectinase dosage was 40%,the enzymatic hydrolysis temperature was 51 ℃,and the enzymatic hydrolysis time was 116 min;2)The optimal process conditions for the fermentation of tobacco stem extract by the aroma-producing functional microorganisms A1 and A2 were as follows: the addition amount of the compound bacterial solution was 8%,and the fermentation temperature was 34.5 ℃,fermentation time was 24 h;3)The optimal process conditions of exogenous addition of proline and glycine to treat tobacco stem extract were as follows: the ratio of added proline and glycine to reducing sugar was 1:1.5,the reaction temperature was52 ℃,the fermentation time was 13.7 h,and the pH was 6.97.(3)Comparing the chemical components and aroma substances of tobacco stem extracts and reconstituted tobacco leaves with different treatments,it was found that microorganisms,enzymes and amino acids all had the effect of improving the quality of tobacco stem extracts.There were significant differences.The T3 treatment,that is,tobacco stem extract and reconstituted tobacco leaves under acid protease,pectinase,and Bacillus and Microbacteria mixed treatment had more coordinated chemical components,higher content of aroma substances,better sensory evaluation,and can better improve the smoking quality of reconstituted tobacco leaf.(4)There were significant differences in the microbial community composition of the tobacco stem extracts of each treatment at the genus level,which affected the changes of the main chemical components of tobacco leaves;the microorganisms in the tobacco stem extracts treated with T3(Acid protease and pectinase,A1 and A2 strains)and T4(Proline and Glycine)were more efficient to transmit,utilize and enhance the ability to resist environmental disturbances;the functions of bacterial carbohydrate metabolism and amino acid metabolism in tobacco stem extract treated with T2(A1 and A2 strains)and T3(Acid protease and pectinase,A1 and A2 strains)were higher.