Preliminary Study On Characteristic Flavor Compounds In Guyue Longshan Rice Wine And The Cause Of Formation

The flavor compounds of Chinese rice wine were studied by chromatography technology. Through principal component analysis (PCA), 18 kinds of flavor compounds were considered as the characteristic flavor compounds in Guyue Longshan rice wine. Flavor compounds in Guyue Longshan rice wine fermentation broth and wine base were detected. The species and quantities of prokaryotic microbes of the rice wine fermentation process were analyzed by the traditional culture method. Through the fermentation test at laboratory scale, the cause of formation of flavor compounds was confirmed.91 kinds of flavor compounds were detected, including 16 kinds of alcohols (except ethanol), 29 kinds of esters, 9 kinds of aldehydes, 9 kinds of organic acids, 17 kinds of amino acids and11 kinds of fatty acids. Through analysis, the variety and content of flavor compounds were obviously different among Chinese rice wines produced in different aeras. Through principal component analysis (PCA), benzaldehyde, aldehyde, isobutyraldehyde, ethyl 2-hydroxy-4-methylvalerate, ethyl butyrate, phenyl ethyl isobutyrate, ethyl benzoate, ethyl phenylacetate, methyl oleate, methyl dodecanoate, ethyl dodecanoate, butanol, 3-ethoxy-1-propanol, 1-enanthol, dodecanol, lactic acid, fumaric acid and lauric acid were considered as the characteristic flavor compounds in Guyue Longshan rice wine.Flavor compounds in Guyue Longshan rice wine fermentation broth and wine base were detected. The results showed aldehydes, organic acids, fatty acids were produced mainly in primary fermentation. Esters were mianly formed in post fermentation. Alcohols and amino acids were produced both in primary and post fermentation. Benzaldehyde, aldehyde 3-ethoxy-1-propanol, enanthol, dodecanol, phenyl ethyl isobutyrate, ethyl benzoate, ethyl phenylacetate, methyl dodecanoate, methyl oleate, ethyl butyrate, lactic acid, fumaric acid and lauric acid were formed in primary fermentation. Isobutyraldehyde was not detected in first 7 days. It mainly formed in post fermentation. Butanol, ethyl dodecanoate and ethyl butyrate were mainly formed in post fermentation.The species and quantities of prokaryotic microbes of the rice wine fermentation process were analyzed by the traditional culture method. During the whole fermentation process, thirteen kinds of prokaryotic microbes were found. They were Bacillus subtilis, Bacillus sp. MO15,Bacillus sp. Epbas6, Bacillus licheniformis, Bacillus sonorensis, Bacillus pumilus, Bacillus altitudinis, Lactobacillus plantarum, Bacillus sp. D6(2007), Bacillus amyloliquefaciens, Bacillus velezensis, Bacillus atrophaeus and Bacillaceae bacterium NJ-25. Bacillus subtilis and Bacillus pumilus were the dominating prokaryotic microbes, which were found during the whole fermentation process.Through the fermentation test at laboratory scale, ethyl caprylate, ethyl laurate, ethyl linoleate, diisobutyl phthalate and fumaric acid were not detected in fermentation broth which were fermented only by pure yeast. Except alcohols, the content of aldehydes, esters, fatty acids and organic acids in fermentation broth by mixing microorganism were more than those fermented by pure yeast. Though majority flavor compounds were produced by yeast, the content of organic acids and esters were observably increased by microorganism in wheat qu. Majority of characteristic flover compounds could be produced by yeast, except enanthol, methyl oleate, methyl dodecanoate and ethyl laurate. Compare to factory scale fermentation, the content of aldehydes, alcohols, esters and fatty acids were lower in laboratory scale fermentation, exceptionally the content of alcohols. Contrarily, the content of organic acids in laboratory scale fermentation were quite more than that in factory scale fermentation.