Research On Control Of Spoilage Microorganisms In Xinjiang Wine Producing Regions

This paper concentrates on the study of wine microorganisms spoilage and quality control of wine in Xinjiang.Collected grape and grape root samples form three major wine production regions of Xinjiang.Isolated major microorganisms from these three types of samples,and identified them by using physiological and biochemical reaction,morphological observation fungal,and molecular biology method.Initially established the database of wine microbial types in Xinjiang region,and database of wine spoilage microorganisms.Explored the influencing factors of harmful microorganisms on the wine quality,and evaluated the wine quality fermented by isolated microbial strains.Ultimately,enhanced the wine quality by study the changes and production of adverse metabolic products.The main results are listed as follows:?1?The molecular biology identification results for isolated yeast showed:among 34 strains of isolated yeasts,there were 26 strains of Saccharomyces cerevisiae,2 strains of Metschnikowia pulcherrima,and 1strains of Hanseniaspora uvarum,Pichia membranaefaciens,Zygosaccharomyces bailli,Saccharomycodes ludwigii,and Dekkera bruxellensis.Evaluated the tolerance of isolated strains,and the spoilage yeast Y72showed the best resistance to 16%?v/v?ethanol?v/v?,200 mg/L SO₂,and 2.5-4.0 pH.?2?The molecular biology identification results for isolated bacteria showed:among 23 strains of isolated bacteria,there are 3 strains of Oenococcus oeni,7 strains of Enterobacter,2 strains of Lactobacillus brevis,2 strains of Lactobacillus plantarum,3 strains of Gluconacetobacter,2 strains of Bacillus subtilis,and 3 strains of Bacillus amyloliquefaciens.The tolerance test showed that B7 and B17has the best tolerance.And the acid production for B4,B5,B6 strains were:17.25 g/L,28.20 g/L,19.50g/L,respectively,and strain B4 showed the strongest acid producing ability.?3?The molecular biology identification results for isolated fungus showed:the main strains were Talaromyces radicus?Mucor irregularis?Rhizomucor variabilis?Cladosporium uredinicola among 15strains of isolated fungus.All of isolated fungus belonged to harmful microorganisms'database.?4?Initially established the database of wine microbial types in Xinjiang region,and database of wine spoilage microorganisms,and there were 72 strains belong to database of wine microbial types in Xinjiang region,and 30 strains were included in database of wine spoilage microorganisms;?5?The brewing test for selected 5 strains of spoilage yeast showed that:the physical and chemical indicators of strains Y58,Y59,Y72 and 71B meet the standard of China's Wine standard,Y47 did not ferment,but produced biofilm,and Y73 showed slow fermentation;The sensory evaluation results indicated that Y47 and Y73 produce unacceptable flavor,and have the lowest scores,71B has the best flavor,and followed by Y59 and Y72;The GC-MC analysis result indicated that Y73 produced the highest content of 4-ethylphenol and 4-Vinylguaiaco1,the unaccepted flavor:the content of 4-ethylphenol was4978.17?g/L.?6?Tested the harmful strains B4 and B15 by using standard FISH method,and universal bacterial probe,B15 was detected,and B15 remained undetected.Real time fluorescent quantitative method was applicable for the detection of spoilage yeasts...