Effects Of Different Yeasts On Carotenoids In Wolfberry Wine

Chinese wolfberry is rich in carotenoids,but it is very unstable,so prone to degradation in brewing technology of Chinese wolfberry wine,degradation products to reduce isoprene compounds,most of these substances with special fruit,lycium can improve the aroma of wine.Chinese wolfberry wine throughout the brewing process,several factors are likely to cause the degradation of carotenoids.This topic focuses on yeast itself and the metabolic environment of lycium barbarum in mainly three types of carotene:zeaxanthin and zeaxanthin dipalmitate esters,study the effect of β-carotene.Experimental study chose different yeast(2 strains of commercial yeast,2,1 Chinese wolfberry wine yeast non Saccharomyces cerevisiae),and three kinds of beta carotene as the sole carbon source were cultured to determine whether it has the ability of degradation of carotenoids.In addition,on determination of 5 strains of yeast growth and fermentation characteristics,and with 5 strains of yeast for fermentation of Chinese wolfberry wine experiment determination of carotenoid degradation in different yeast fermented wine,and C9-C13 drop changes in isoprene such degradation products,the results were as follows:(1)different yeast growth and fermentation characteristicsFrance Angie Saccharomyces cerevisiae,Saccharomyces cerevisiae,Chinese wolfberry wine yeast starts to work slower,but fermented strong and lasting,broth has a different degree of increase of temperature,drop in pH to a different degree of fermentation broth.Grape juice spore Hanson yeast and Mei Mei’s yeast can grow in the goji juice after pretreatment,fermentation ability cannot be fermented,4 days after the termination,fermentation temperature and pH changes are not large in magnitude.(2)5 yeast itself cannot directly use carotenoids.(3)Using 5 types of different Yeast fermentation of Chinese wolfberry wine,fermentation of zeaxanthin,zeaxanthin dipalmitate acetate,beta-carotene to a different degree of degradation,primarily yeast metabolism leading to medlar broth environment has changed,and with the extension of time,light and temperature changes in degradation of carotenoids.Effect than non-Saccharomyces cerevisiae Saccharomyces cerevisiae,mainly Saccharomyces cerevisiae vigorous and full,many metabolites,fermented liquid environment changes,weak non-Saccharomyces cerevisiae,fermentation is incomplete,fermentation environmental change is relatively small,resulting in less degradation of carotenoids in the fermentation process.(4)5 yeast in the fermentation of Chinese wolfberry wine reduce isoprene compounds vary,raise and lower instability occurs,3 strains of Saccharomyces cerevisiae fermentation to reduce isoprene compounds than 2 non-effect of Saccharomyces cerevisiae wine strains.5 Yeast fermentation is over,compared with fermentation,and isoprene compounds increased overall,but since isoprene compounds from fermentation liquid reduction environmental impact,ultimately the type and content of increase is not very big.Reduce isoprene compounds changes directly depend on the degree of carotenoid degradation,followed by their containing unsaturated material combined with changes in fermented liquid.Carotenoids fermentation by yeast system of complex chemical and physical factors influence,except under the influence of yeast metabolism,but also under the influence of light,oxygen,temperature,etc.Different yeasts will form a different environment,different carotenoids degradation led to reduce isoprene compounds in fermented liquid content and types of changes.In 3 strains of Saccharomyces cerevisiae fermentation effect on carotenoids,reduce isoprene compounds produced relatively more,raising and lowering changes;2 weak non-Saccharomyces cerevisiae fermentation time on the carotenoid lowering effect,reduce isoprene compounds produced less,raising and lowering changes little.