Effect Of Inoculation Mode Of Brewing Microorganism On The Quality Of Fruit Wine

Fruit wine is much loved by so many people because of its rich nutrients,low alcohol content and rich fruit flavor.Fermentation is a complex microbial metabolism process,and the mainly microorganisms involved are Saccharomyces cerevisiae,non-Saccharomyces cerevisiae and lactic acid bacteria.The interaction between them makes the aroma of fruit wine stronger.The more types of microorganisms,the more uncontrollable is the fermentation process.And these microorganisms could make the fruit wine rot.This thesis is mainly divided into two parts.The raw material of the first part is black raspberry wine,which is aimed at studying the community structure of fungi in the process of natural alcoholic fermentation(AF)and the effect on the quality of black raspberry wine of the interaction between Saccharomyces cerevisiae and non-Saccharomyces cerevisiae-Torulaspora delbrueckii.The raw materials of the second part is Cabernet gerischet grape wine,which is aimed at studying the community structure of bacterial during malolactic fermentation(MLF)and the effect on the quality of the different sequence of Lactobacillus plantarum inoculationThe results are as follows(1)Microbial fermentation process in AF process of black raspberry wine.The high-throughput sequencing technology was used to study the fungal community in the natural black raspberry wine AF process.And it was concluded that the dominant bacteria group was Ascomycota and Basidiomycota at the phylum level while Saccharomyces was the dominant level at the genus level.Traditional microbial culture techniques were used to study the fermentation process of microorganisms under different inoculation modes(Saccharomyces cerevisiae and non-Saccharomyces cerevisiae-Torulaspora delbrueckii)The conclusions are as follows:Different modes of yeast inoculum have their own advantages and disadvantages.Natural alcohol fermentation is difficult to control and harmful microorganisms are easy to breed.However,the process of inoculating commercial Saccharonyces cerevisiae is easy to control.The fermentation efficiency is high,and AF is completed within 7 days.Inoculated commercial non-Saccharomyces cerevisiae and commercial Saccharomyces cerevisiae are slightly inhibited between themselves and AF is completed in 9 days,which is two days shorter than the fermentation by inoculating commercial Saccharomyces cerevisiae.So the impact of the fermentation process was not significant.(2)The evaluation on the quality of black raspberry wine brewed under different modes of yeast inoculation.The Basic physical and chemical indicators are as follows:three black raspberry wines have completed AF,and meet the quality requirements of fruit wine;aroma components:the content of aroma substances in the natural AF wine sample(BU)is relatively more,and this indicates that indicating the cooperation of multiple yeasts can promote the formation of volatile aroma components in fruit wine.However,the natural AF is difficult to control.In order to ensure the quality of wine brewing controllable,we selected yeast for brewing wine.The addition of non-Saccharomyces cerevisiae-Torulaspora delbrueckii increased the content of four types of ester compounds such as ethyl caproate,isoamyl acetate,ethyl butyrate,ethyl isobutyrate and ethyl propionate,and the content of the three types of alcohol compounds such as 3-methyl-1-pentanol,1-propanol and ethanol,but reduced the content of acetic acid.Biogenic amine content:the content of biogenic amines is related to the number of yeasts.The more yeasts,the higher the content of biogenic amine.So the natural AF wine sample(BU)has the most biogenic amine contents,and the wine sample(BS)of only added commercial Saccharomyces cerevisiae has the least biogenic amine contents.Non-Saccharomyces cerevisiae-Torulaspora delbrueckii contains enzymes involved the formation of putrescine and spermidine(3)Microbial fermentation process in MLF process of wine.High-throughput sequencing technology is used to study the bacterial community in the natural wine MLF process,and it was concluded that the dominant bacteria groups were Proteobacteria,acidobacteria and Firmicutes at the phylum level.At the genus level,horizontal,and Tatumella are dominant genus in the early and late fermentation,and Pantoea is the dominant genu in the mid-fermentation.From wine-MLF processing Perspective,the commercialization of Lactobacillus inoculation significantly shorten the MLF time,and the wine usually needs about 40 days in natural MLF.After this commercial experiment of lactic acid bacteria were added,it took 20 days and 14 days to complete MLF.And it took the shortest time under the inoculation the fermentation mode.Therefore,the inoculation is the most economical and efficient mode of MLF wines(4)The evaluation on the quality of wines brewed under different Lactobacillus planlarum inoculation sequences.The Basic physical and chemical indicators are as follows Three brewed wines all meet the requirements of national standards;aroma components the content of aroma substances in the wine sample(GC)inoculated at the same time is relatively the most,indicating that simultaneous inoculation of lactic acid bacteria is more conducive to volatility in fruit wine Generation of aroma components.Biogenic amine content:Although the total biogenic amine content is the highest in GC,the content of various biogenic amines is also within the national limit.Therefore,the mode of simultaneous inoculation of Lactobacillus plantarumis more conducive to the improvement of fruit wine quality.