Screening And Application Of Saccharomyces Cerevisiae Specialized For Lemon Beer

Lemon is rich in nutrients and is known as one of the most medicinal fruits.At present,there is a lack of special Saccharomyces cerevisiae for lemon beer,so it is necessary to screen out yeast suitable for fermenting lemon beer and optimize fermentation process.In the article,lemon and malt are used as raw materials to screen special brewer bacteria suitable for lemon beer fermentation.The selected strains are applied to the brewing of lemon beer,the fermentation process is optimized,and the lemon beer is subjected to debittering research to finally obtain lemon beer.The main findings of this topic are as follows:1.Specific yeast screening for specificity.The strain 1# was obtained by separation,screening and purification of the strains in the lemon soil.The fermentation performance test,hypoglycemic ability test and molecular identification of the strain were carried out,and the number was yeast G.Then,7 strains of Saccharomyces cerevisiae including yeast G were tested for fermentation performance,in which Saccharomyces cerevisiae B,D,and G were fast,low in residual sugar,and high in sensory product scores.The stress resistance test was carried out again.The experimental results showed that the strain D was suitable for the pressurized fermentation with a slightly lower pH of the fermentation broth and the fermentation broth was neutral with pressure fermentation.The strain G was suitable for the fermentation with low pH of the fermentation broth.2.Application research of excellent yeast,applying the selected strain to the fermentation of lemon beer,orthogonal design of lemon juice treatment method,fermentation temperature,raw wort concentration,lemon adjuvant addition time,lemon adjuvant addition amount and hop addition amount experiment.The results showed that the optimal fermentation conditions for lemon beer were: adding lemon fermentation broth to lemon beer,fermentation temperature 19℃,original wort concentration 10.5 °P,boiling time 40 min,adding hops 0.9 g/L,in fermentation 12 Add 13% lemon broth in the daytime,then store the wine and clarify the finished lemon beer.After verification,the lemon beer sensory score is 86 points.3.Design response surface experiment for debittering rate,adding 3g/L naringin to lemon juice,placing lemon juice at 50℃,65 min,and finally debittering rate is 22%;resin on limonin and pomelo The debittering effect of dermatan is better than that of naringin.The effect on nutrient composition and mouthfeel is less than that of naringin.The best debittering process of resin adsorption is to add 3.8 g/L resin to lemon juice at 36℃.The effect was 21 min.In the single factor experiment,the resin was treated at a shaking speed of 140 r/min.The debittering experiment was carried out under the above conditions.The debittering rate was as high as 51.3% and the bitterness score was 2.1.Through the screening of S.cerevisiae,the S.cerevisiae for lemon beer was obtained;the selected S.cerevisiae was applied for research,and the finished lemon beer was finally obtained by optimizing the fermentation process and debittering process.