Screening And Yield Optimization Of Aromatic Alcohol-producing Food-Borne Strains

As members of the aromatic alcohol family,2-phenylethanol and tryptophol are widely used in the fields of food,tobacco,cosmetics and medicine.With people's attention to natural products,the use of microbial technology to produce natural aromatic alcohol substances,people's attention.Material sources for electronic cigarette smoke fluid rich aroma,developing electronic cigarette product has good flavor,this thesis with tobacco,peduncle,myrica rubra and grapes for the nutrients screening for 42 of food-borne strain,tobacco,peduncle,myrica rubra and grapes as fermentation substrates,and selects 17 group has good flavor ?strains + substrate?combination,compared with sweet and sour taste,mellow taste,ester,milk flavor,or fruit aroma is stronger and less irritating.Seventeen kinds of aromatic compounds were analyzed by gas chromatography-mass spectrometry(GC-MS).Esters,alcohols and acids were dominant in the tobacco stem fermentation matrix,and the presence of 2-phenylalcohol was detected.In the fermentation matrix of red bayberry and grape,esters and alcohols play a dominant role.Especially when fermented with saccharomyces cereviniae KMLY1-2,the content of 2-phenylethanol is significantly increased,and the presence of tryptophol is also detected in the fermented grape KMLY1-2.Three strains of yeast,two strains of lactic acid bacteria and two strains of bacillus were taken as the research objects,and the combined transformation of two strains was carried out.Four double fermentation combinations and two single fermentation combinations were screened by olfactory and GC-MS methods.Based on the yield of 2-phenylethanol,the optimal single factor conditions were obtained by single factor optimization of 4 double bacterial combinations.At the same time,the optimum conditions for producing 2-phenylethanol and tryptophol were obtained by orthogonal optimization of bayberry and grape fermented by KMLY1-2.The results of sensory quality evaluation showed that the fermented samples had better aroma harmony,fuller aroma,lighter odor,cleaner aftertaste and higher suction quality.In order to further improve the yield of 2-phenylethanol and tryptophol,KMLY1-2 was used as the research object to screen and obtain a medium with less nutrients(transformation medium),and then the single factor experiment was used to optimize the medium composition and culture conditions to obtain the best conditions.This research provides strong technical support for the development of characteristic style e-cigarette products and diversified research on e-cigarette style,which provides a theoretical basis for industrial production of 2-phenylethanol and tryptophol.