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Yellow Rice Wine Collaboration For Flora Analysis, Screening Fine Strains And Mixed Strains Fermentation Research

Posted on:2012-04-25Degree:MasterType:Thesis
Country:ChinaCandidate:Y Q YinFull Text:PDF
GTID:2241330395464395Subject:Agricultural Products Processing and Storage
Abstract/Summary:PDF Full Text Request
In this thesis, base on the research of rice wine starters, Microflora, superior strains and change of compositions of the mixed molds during its fermentation process have been systematic studied during fermentation process by traditional microorganism fermentation technology,modern molecular biology technology,modern instrument analysis technology combining physical and chemical index analysis.1. Mold, yeast and bacteria in rice wine starter have been separated on a large scale by variety of separation mediums. The molecular typing RAPD fingerprints method was developed by combination of3random primers that screened from28random primers.132strains of yeasts were isolated from the three rice wine starters (DYT, HST and HSG) and were analyzed with RAPD fingerprints.22genotypes were obtained and then were clustered to9genetic lineages using UPGMA clustering method. The representatives’strains of each genotype were randomly chosen for the determination of26S rDNA D1/D2domain sequences and phylogenetic tree was drawn. All of the yeast isolates belonged to4species:Clavispora lusitaniae, Pichia fabianii, Saccharomyces cerevisiae and Pichia mississippiensis. High level of genetic diversity and different relationship are found among yeast isolates.216bacterias were molecular typed through RS-PCR, then16S rRNA domain sequences were analysied. Bacillus sp. was dominant bacteria. Bacteria in starter include Bacillus subtilis, Bacillus licheniformis, Bacillus amyloliquefaciens, Bacillus cereus, Klebsiella oxytoca, Acinetobacter baumannii and Enterococcus faecalis.168molds’ITS rDNA fragment were amplified and sequenced. The predominant fungus of three rice wine starters were Absidia corymbifera、Aspergillus oryzae and Aspergillus flavus.What’s more, Rhizomucor pusillus、Aspergillus niger、Aspergillus tubingensis、Penicillium citrinum and Rhizopus microsporus also were separated and identified in three rice wine starters.2. Saccharomyces cerevisiae HSTY-30was screened from all these yeast strains for its superior performance through TTC coloration in plate、tube fermentation and performance index include alcohol-endurance, total sugar and lethal temperature. It has high inherited traits stability, growth uniformity, high physiological patience and high fermentation capacity, its alcoholic-producing ability was8.93g/100mL, residual sugar was1.2g/L, lethal temperature was56Κ, alcohol-endurance was16%(v/v). Aspergillus oryzae DYT-30was screened for its high enzyme activities include glucoamylase (1678u/g·Qu), α-amylase (68.6u/g·Qu) and proteinase (839.9u/g·Qu) by transparent-loop in plate combined enzyme activity determination.3. The mixed fermentation technology of Aspergillus oryzae、Aspergillus flavus、Absidia corymbifera、Aspergillus niger、Penicillium citrinum and Rhizopus microsporus and its glucoamylase, α-amylase, proteinase and cellulose activities were studied. The change of compositions of the rice wine with mixed molds and the traditional rice wine were studied during their fermentation process. The results suggested that the change tendency of compositions during ten kinds of fermentation process was similar:pH declined, temperature increased firstly and then declined slowly to the highest temperature34℃.The aminophenol content、total polyohenol content and alcohol yield increased, alcohol content and total esters declined of the rice wine with mixed molds compared with the traditional rice wine. An analytical method was applied to determine higher alcohols and esters in rice wine by solid-phase microextraction in combination with gas chromatography (SPME-GC). Experimental results revealed that the variety and content of flavor compounds were obviously different among rice wines. The relative content and ratio of higher alcohols and esters in some rice wine with mixed molds were similar to traditional rice wine, basically reached its flavor composition.
Keywords/Search Tags:Chinese rice wine, starter, yeast, mold, molecular identification, strainscreening, mixed fermentation
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