Determination Of Fermented Grains Of Fen-flavor Liquor And Research On The Characteristics Of Core Fungi

The Fen-flavor liquor is pure and fragrant,soft and sweet,natural and harmonious,and the aftertaste is refreshing,it's koji is made from the core fungus added to the grain material,fermented in ground cylinder and distilled to obtain the wine.The koji is the key to the quality of the wine,and the core fungus in the koji determines the quality of the koji.This paper explores the fermentation characteristics of core fungus in koji of Fen-flavor liquor,provides theoretical basis for the optimization of brewing process;The physical and chemical indicators of the fermented grains were determined,and the data reference for the subsequent production was provided;The response surface method was used to optimize the fermentation conditions of the dominant ester-producing yeast,which provided a theoretical basis for the production of high ethyl acetate-containing liquor in the koji.1.The determination of physical and chemical indicators of fermented grains.The multiple physical and chemical indicators of the fermented grains(including water,acidity,residual sugar residue,residual amount of ethanol and ethyl acetate)during fermentation were measured to control the variation of the main indicators of the fermented grains.The results showed that both water and acidity holded an upward trend,and the residual amount of reducing sugar gradually decreased.The residual of ethanol rose first and then decreased,while the residual amount of ethyl acetate was unstable and fluctuated.The time of peak production of each component is combined considered to adjust the distillation time of the material to maximize the content of each component to achieve the best results.Detecting various indicators during the fermentation process,not only can control the fermentation of the joki,find problems in the fermentation process and deal with it in time to avoid large mistakes and problems,but also can grasp the changes in the nature and indicators of the joki,and provide data reference for subsequent production,thus,treatment and adjustment can be made during the fermentation to improve and improve the quality of the koji.2.The fermenting properties of fungus in joki of Fen-flavor liquor.Saccharifying power,esterification power and liquor-producing power are the main indicators of quality control of koji.In order to Improve the production process of fen-flavor liquor,we measured the characteristics of nine kinds of fungus added in the koji by microbiological method,spectrophotometry,direct titration,gas chromatography,etc.,which mainly includes the morphological characteristics and identification,growth curve,saccharification power,alcoholization power and esterification power of the strain.The results indicated that among these fungus,the one that has the strongest saccharifying power was Rhizopus with the maximum activity of glucoamylase 7.68 U/m L;also among these yeast,Endomycopsis had the strongest esterification power with the highest content of ethyl acetate 0.705 mg/m L;Geotrichum candidum had the strongest ability to produce ethanol with the highest content of 40.72 mg/m L.This study provided the theoretical basis for the brewing technology of fen-flavor liquor.3.The response surface method was used to optimize the fermentation conditions of the superior yeast to produce ethyl acetate.Ethyl acetate is the main aroma component of Fen-flavor liquor,in order to improve the ethyl acetate production capacity of the koji,the culture conditions of the dominant yeast strains which producing ethyl acetate were optimized.The sugar content in medium,inoculum and fermentation time were carried as the single factors for the experiment,and the results showed that when the inoculation amount was 4%,the culture time was 2 days,and the medium sugar content was 40 g/L,the ethyl acetate yield reached the highest value under each condition respectively;The results of response surface experiment showed that the effects of various conditions on the yield of ethyl acetate were as follows: fermentation time > sugar content > inoculum.The optimal conditions for the fermentation condition verification test were as follows: when the fermentation time was 2 days,the sugar content was 41 g/L,and the inoculum volume was 4%,the average maximum yield of ethyl acetate could reach(0.696±0.047)mg/m L.This result provides a theoretical basis for the use of superior yeast to produce high ethyl acetate-containing liquor in koji.