Effect Of Temperature On Esters Metabolism During Wine Yeast Fermentation

This paper mainly studies four Saccharomyces cerevisiae genes related to esters(ATF1,EHT1,IAH1 and FAA1),and selected four strains of Saccharomyces cerevisiae which fermented simulation Grape Juice medium,meanwhile,set four different temperature(8?,15?,25?and8?-15?-25?),in the fermentation process,relative expression analysis at different time points of Saccharomyces cerevisiae using real-time fluorescence quantitative PCR,content of esters with simulated liquor was measured by SPME-GC-MS after fermentation,explore the effect of different temperature,strains on gene expression and esters content.At 8? during fermentation,the gene expression of D254 is high,ethyl butyrate,isoamyl acetate and 2-high hexenoic acid ethyl ester content in the fermentation liquid is also high,71 B has the highest amount of esters and the most species,the higher content of ethyl esters of 4 strains in fermentation liquid,and decanoate was the lowest at 8? fermentation;At 15 ? fermentation,Y2 gene expression level is high,high ethyl acetate,ethyl butyrate,ethyl heptanoate,2-hexenoic acid ethyl ester and hexanoic acid isobutyl,nonanoic acid ethyl ester and isobutyl octanoate content in the fermentation liquid,71 B has the highest amount of esters and the most species;at 25 ?,the high gene expression of S1.The fermentation liquid of heptanoic acid,ethyl ester,hexanoic acid,2-methylpropyl ester,octanoic acid,3-methylbutyl ester and butanedioic acid,diethyl ester was higher,71 B has the highest amount of esters and Y2 has the most species of esters;at 8-15-25 ? temperature fermentation,the gene expression of 4 strains differ slightly,71 B has the highest amount of esters and Y2 has the most species of esters.The results show that the temperature of 15? during fermentation,the relatively high gene expression level,total esters less then,simulation of liquor obtained after fermentation of the same,more types of esters.The study found that high expression of ATF1 gene,the ethyl acetate content was also higher,higher expression of IAH1 gene,isoamyl acetate content is higher,while the EHT1 gene expression was high,increased the content of ethyl hexanoate,ethyl caprylate and ethyl decanoate.In this paper,we studied the effects of different temperature and different yeast on the content of esters and the content of esters.