Effects Of Mixed Fermentation Of Schizosacch-aromyces Pombe And Saccharomyces Cerevisiae On The Qulaity Of Pinot Noir Dry Red Wine

Schizosaccharomyces pombe has the excellent properties of brewing high-quality dry red wine.It can effectively reduce malic acid content,improve aroma quality and increase wine color stability during alcohol fermentation.However,alcoholic fermentation by S.pombe alone,which takes a long time and has a relatively high risk of microbial infection.The study took the 'Pinot Noir' grape from Hexi Corridor of Gansu Province as raw material,and used S.pombe and commercial Saccharomyces cerevisiae to carry out simultaneous and sequential inoculation fermentation to analyze the biomass of the fermentation process,the malic acid content,color and aroma quality of the wine.Meanwhile,the safety factors histamine and urethane content were measured.Combined with sensory evaluation,the effects of S.pombe and VR vaccination methods on the quality and safety of'Pinot Noir' dry red wine were investigated.The main results are as follows:1.S.pombe and S.cerevisiae were mixed inoculated with 1000:1.During the fermentation,the biomass of S.pombe decreased slowly,and S.cerevisiae had a weaker effect on the growth of S.pombe.The highest values of total anthocyanins,chroma and softness indexes in wine were 120.66 mg/L,1.14,126.22 g/L respectively;the highest contents of esters and higher alcohols in the aroma components were 2451.53 and 1842.41 ?g /L.Fruity and floral aromas are obvious,histamine content is a minimum of 0.25 mg/L and ethyl carbamate is not detected.Comprehensive evaluation is better than the control and inoculation treatment in other ratios at the same time.2.S.pombe and S.cerevisiae VR were sequential inoculated with interval 8 days.During fermentation,the biomass of S.pombe strains decreased slowly.The highest values of total anthocyanins,chroma and softness indexes in wine were 134.34 mg/L and 1.05?127.62 g/L respectively.The contents of esters and higher alcohols in the aroma components were1648.07 and 1083.09 ?g/L respectively.In combination with PCA,the inoculation at 8 d interval had a high contribution to the aroma.The minimum histamine content was 0.14 mg/L.No urethane was detected.The comprehensive evaluation was better than the comparison and other days of sequential inoculation.3.Compared with the 1000:1 mixed inoculation,the total anthocyanin content and the softness index of the wine obtained by the 8 d interval were increased by 11.34% and 0.78%respectively.Phenethylacetate,phenylethyl alcohol and damascenone,which have a positive contribution to aroma,have the highest content and threshold;histamine content hasdecreased by 44%;sensory evaluation is slightly higher than 1000:1 inoculated liquor sample.S.pombe and S.cerevisiae VR inoculation fermentation with intervals of 8 d is a better mixed fermentation method.4.S.pombe and S.cerevisiae VR were inoculated sequentially and inoculated at the same time.The content of malic acid in the finished wine was lower than that of the control wine sample,which was reduced by 22.22% and 55.56% respectively,indicating that S.pombe can effectively reduce the wine sample by participating in fermentation.The sharp malic acid increases the softness of the wine.In summary,it can be seen that the use of S.pombe strains during wine brewing can increase the total anthocyanin content,chroma value and softness index of the finished wine.It can also improve the aroma quality and reduce the malic acid content,avoiding the histamine and urethane produced by the MLF process.Safety can be improved as well.