Analysis Of The Function Of Saccharifying Power And Esterifying Power Of Daqu For Light-fragrant Chinese Liquor Brewing And Their Fungus Community Structures

Daqu is the effective carrier of microbes and enzymes duringChinese liquor brewing. It is named as the bone of the wine becauseof its functions on saccharification, fermentation and aroma. Theoutstanding characteristic of Daqu is raw materials used withoutsterilization, inoculation from environment raw materials and openculture, which made the microbial quite complex. Thereforebrew microorganisms it becomes an important research content.Daqu is the saccharifying starter for Chinese liquor, so fungi whichwere recognized as producing enzymes for starch degradationshould plays an important role. This study mainly analyzed thecommunity structure of fungi structure of community, and thefunction of saccharifying and esterifies enzymes in Daqu forlight-fragrant Chinese liquor making.Firstly the Fungi community structures of Daqu for light-fragrantChinese liquor were investigated by barcoded pyrosequencing. Theresults showed that, the results of different genomic DNAextracting Kits and different regions (18S V4and ITS) werecoincidental. The mainly fungus of Daqu from hot and cold seasons were same almost, which were mould and yeast, mould includeRhizopus oryzae and Lichtheimia corymbifera, yeast include Pichiakudriavzevii and Saccharomycopsis fibuligera. The contents ofmold were obviously higher than that of yeast, and the percentageof yeast decreased in cold season obviously. So these microbeswere confirmed the major Fungus of Daqu for light fragrant Chineseliquor making.Saccharifying power has a great influence on the brewingprocess, especially for the early stage of Daqu used in light fragrantChinese liquor making. Daqu with different saccharifying power onlywere used in brewing experiment, the results showed that whensaccharifying power were1200U and1500U, yeast grew too fast,in the beginning of the two day, which is prone to make the strainspremature aging, was not coincident with the producing regularpattern. When the saccharifying power was900U, yeast reachedthe highest point at the fourth day, which was fit the regular pattern;when saccharifying power were600U and300U, the grown speedand number of yeast decreased, the highest value of the yeastquantity reduced, which may lead to the incompletely fermentation.Combined with alcohol content changes, it showed that highersaacharifying power, such as900U， contributed to the productionprocess.Esters are the important flavor substance. Increase of esterscontent was studied in many famous liquor making enterprises. Forlight fragrant Chinese liquor, the ester was ethyl acetate. In order tofurther clarify the mechanism of the synthesis of ethyl acetate,ester syntheses were investigated by addition esterification enzymes in pure chemical system and winemaking environment.The results showed that, in the pure chemical system that containsonly acetic acid and ethanol system, total esters increased withthree kinds of esterification enzymes addition, and reached a peakwhen the additive amount of esterification enzymes was6g. Whenaddition into the medium of sorghum similar to production, totalesters increased concomitantly increases of additive amount ofesterification enzymes, but the total ester of contrast were higherthan that of the lower additive amount of esterification enzymes.Because the environment is a multi-microbes, multi-enzymecomplex process of interaction, where a lot of the mechanism isstill not understood, its causes need further research and analysis.