| Macheng old rice wine has a history of thousands of years.It is made of glutinous rice and special koji.It has a clear color,a mellow and sweet taste,and is rich in nutrients and functional ingredients.Therefore,this paper is the first to study the conditions of its brewing process and its The production process of distiller's koji was optimized,and its functional components were qualitatively and quantitatively analyzed by high performance liquid chromatography.The enoyl-Co A hydratase gene of the functional component protocatechuic acid in the metabolism of Saccharomyces cerevisiae was cloned by modern biomolecular methods.And analyzed protein bioinformatics,the main conclusions are as follows:(1)Taking the old rice wine with different fermentation time as the research object,the dynamic changes of the total acid,total sugar,alcohol content and amino nitrogen content in the old rice wine fermentation broth were measured,and the types of microorganisms in the fermentation broth were studied..The results showed that:0?4 days is the pre-fermentation period,the total sugar content is at a higher level and the alcohol content is low,and 5?30 days is the post-fermentation period,the total sugar content is decreased,and the alcohol content is increased.Four strains were screened and identified from the fermentation broth.Y1 is Wickerhamomyces anomalus,Y2 is Saccharomyces cerevisiae,and M1 and M2 are Rhizopus oryzae..(2)The selected molds and yeasts are compounded according to a certain ratio to make koji,which are compound koji 1(M1+M2+Y1)and compound koji 2(M1+M2+Y2).By measuring the enzyme activity of the compound koji and various physical and chemical indexes of the finished old rice wine,the koji with high saccharification and fermentation power is prepared,and the flavor components of the old rice wine are analyzed by combining with gas chromatography.The results showed that,compared with the commercially available koji,the saccharification power of compound koji 1 and compound koji 2 increased by 19.6% and 12.3%,respectively,and the liquefaction power of compound koji 1 and compound koji increased by 19.0% and 10.6%,respectively.The protease activity of compound koji1 and compound 2 was increased by 10.5% and 6.8%,respectively,and the alcohol content of fermented rice wine of compound koji 1 and compound 2 was increased by 23.5%and 14.7%,respectively.The main flavor components of the old rice wine are alcohols and esters.Combined with the sensory evaluation,compared with the commercially available koji,the old rice wine made with compound koji has a higher taste score.(3)Qualitative and quantitative analysis of the functional components in the old rice wine using high performance liquid chromatography,detected 11 kinds of phenols,which are gallic acid,protocatechuic acid,P-coumaric acid,vanillic acid,and ferulic acid.,Chlorogenic acid,quercetin,catechin,epicatechin,rutin,caffeic acid;8kinds of organic acids were detected,namely oxalic acid,tartaric acid,L-malic acid,lactic acid,acetic acid,citric acid,amber Acid,pyruvic acid;?-aminobutyric acid is detected.It shows that old rice wine is rich in functional ingredients,which play an important role in the nutritional value of old rice wine.(4)Protocatechin is the most important metabolite in the metabolic pathways of most aromatic compounds,and enoyl-coenzyme hydratase is one of the important enzymes in Saccharomyces cerevisiae to metabolize and produce protocatechin.In this study,the enphthalein coenzyme hydratase gene was cloned from the genome of Saccharomyces cerevisiae,and its bioinformatics was analyzed.The results showed that the gene ech is 815 bp in length,encodes 271 amino acids,and is a stable protein with a molecular mass of 31.7 k D;the theoretical isoelectric point p I is 8.39.Prediction and analysis of secondary structure and tertiary structure show that ?-helix and irregular coils are the main components of the protein structure. |
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