Screening And Applying Of Functional Mold In Moutai-flavor Baijiu

Mold plays an important role in the formation of flavor substances in soy sauce type white wine.Exploring the mold-producing properties,metabolic properties and the influence of molds on other major brewing microorganisms is an effective way to study the influence of molds on soy sauce type white wine.To study the functional mold in the production of soy sauce type liquor,not only the enzymatic activity of mold should be considered,but also the enzymatic systems such as amylase,protease and esterase.In this study,the isolation and screening of mold,metabolic characterization and influence on stack cultivation in the brewing process of Maotai-flavor white wine were studied,and the main results are as follows.(1)109 potential strains were isolated and screened by dilution coating plate method from Maotai-flavor white wine majolica production process,finished majolica and stacked spirits and observed their colony characteristics and microstructure,and further screen the strains that have a positive impact on the production of soy sauce spirits through the transparent circle experiment and enzyme activity assay.Molecular biology identification confirmed that the screened moulds included 11 genera,namely Aspergillus tubingensis,Aspergillus nidulans,Absidia,Penicillium marozzi,Aspergillus niger,Aspergillus flavous,Rhizopus microsporum,Penicillium oxalate,Paecilomyces variotii,Monascus purpureus and Lichtheeimia.The strains obtained from the screening covered a wide range of mycobacteria and contained several species and genera.(2)Carefully consideration of enzyme activity and combination of species relationship,the metabolic properties of six strains of molds with high enzymatic activity were studied by liquid fermentation,including Rhizopus microsporum(GTM-110)、 Aspergillus flavus(GTM-134)、 Aspergillus niger(GTM-358)、Monascus purpureus(GTM-360)、 Aspergillus tubingensis(GTM-944)and Penicillium oxalicum(GTM-1897).(3)The effect of mold on yeast and lactic acid bacteria was investigated by co-culture test,and it was found that when six strains of mold were co-cultured with GTY-10(Saccharomyces cerevisiae)、 GTY-99(Wickerhamomyces anomalus)and GTY-610(Issatchenkia orientalis),the yield and alcoholic strength of ethyl acetate could be improved to different degrees by adjusting the addition of mold.When six strains of mold were cocultured with GTL-74(Lactococcus lactis)and GTL-592(Lactobacillus plantarum),GTM-358 and GTM-360 could significantly reduce the lactic acid production in the fermentation broth.(4)GTM-134、GTM-358 and GTM-944 were selected for the stack culture test,and it was found that the addition of GTM-134 and GTM-358 could increase the content of ethyl acetate in the spirits;the addition of GTM-944 could increase the content of ammoniacal nitrogen in the spirits.The addition of the three strains of mold could increase the types and yields of flavor substances and improve the quality of soy sauce type white wine.