结晶麦芽对精酿啤酒发酵工艺及品质的影响OA

Craft beer was brewed with crystal malts of different chromaticities(78.4,113.7,136.7,221.5 EBC).The viable yeast in fermentation system and physicochemical indicators,color parameters,volatile flavor compounds,and sensory quality of beer were determined to investigate the effects of malt chromaticity on the fermentation process and quality of craft beer.The results showed that addition of crystal malt 10%with chromaticity lower than 136.7 EBC exerted no significant influence on yeast fermentation.However,the fermenting power of yeast decreased markedly when the chromaticity rose to 221.5 EBC.The addition of crystal malt had no significant effect on the diacetyl reduction capacity of yeast(P>0.05).A strong positive correlation(r=0.991)existed between beer chromaticity and crystal malt chromaticity.The increase in chromaticity reduced the lightness(L*)of beer,while enhancing red-green chromaticity coordinate(a*)and yellow-blue chromaticity coordinate(b*).Sensory evaluation demonstrated that the rise of crystal malt chromaticity improved roasted aroma,caramel flavor,mouthfeel richness,and sweetness of beer,and alleviated bitterness and astringency.The beer brewed with crystal malt of 113.7 EBC obtained the highest sensory preference score.Analysis of volatile flavor compounds further revealed that the addition of crystal malt increased the contents of characteristic flavor substances including methyl decanoate,linalool,γ-nonalactone,and damascenone.This study provided a theoretical basis for rational selection and flavor regulation of crystal malt in craft beer production.