Research On Brewing Technology Of Roselle Mead

As people’s living standards improved,their drinking habits gradually developed from drinking hard liquor to drinking nutrition and health low wine.So the development of mead should also turn from liquor to low wine,from the flavor wine to health wine,from comnpound wine to fermented wine.In this study,Roselle and honey were added together to fermente on the basis of the mead,and obtain the ideal process parameters of roselle mead.And if Liquor returning fermentation can increase roselle mead’s Aroma components and its oxidative stability were studied too.The results are as follows:1.Through study on the brewing technology of mead,the results were as follows:During the fermentation,types of honey,types of yeast,inoculation quantity of yeast,dosage of pectinase,ratio of roselle solid to liquid and fermentation temperature were studied by using single factor analysis method.And finally chose fermentation temperature、dosage of pectinase、inoculation quantity of yeast and ratio of roselle solid to liquid four factors use response surface method through Design-Expert 8.0 Box-Behnken to create three mathematical models describing alcohol degree(R1),sense scores(R2)and transmittance(R3)and got their duality equations.R1=8.24+0.53A+0.071B+0.53C+0.36D+0.025AB+0.50AC-0.34AD+0.52BC+0.41BD-0.050CD-0.31A2-0.62B2-0.33C2-0.53D2R2=82.40-4.67A+1.17B+0.50C+0.67D+1.50AB+0.OOOAC-4.00AD-2.75BC+1.25BD-4.25CD-2.99A2-2.99B2+2.76C2+0.51D2R3=78.40+0.84A-1.36B+1.60C+3.20D-4.00AB-6.70AC+2.80AD+1.00BC+0.50BD-3.70CD-3.44A2-8.54B2+4.41C2-2.29D2The optimum technological conditions are:fermentation temperature at 20℃,dosage of pectinase is 0.45mL/100mL,inoculation quantity of yeast as 2.5%,ratio of Roselle solid to liquid is 1.25g/100mL。And finally got roselle mead at 7.0vol%,sense scores 87,transmittance 82%.2.Liquor returning fermentation in increasing aroma components of roselle meadThe analysis of gas chromatography/mass spectrometry(GC/MS)on aroma components of roselle mead fermented in different times and different proportions were undertaken,the results indicate:(1)There were 78 kinds of aroma components of roselle mead detected after two times liquor returning and 87 kinds of aroma components were detected after three times liquor returning,higher than brut wine and six months aging wine whice has 61 and 75 kings of aroma components.There are 3.50%esters of aroma components in brut wine and after six months aging,and it increased in 9.41%.And after two times liquor returning,esters increased to 8.96%,whice is 0.45%less than six months aging wine.And after three times liquor returning,esters increased to 14.49%,whice is 4.1 times than brut wine and 1.5 times than aging wine.But we have to point out that,along with the liquor returning times increase,The acids of roselle mead increased.There are 6.87%acids in brut wine,and only 3.39%in aging roselle mead,but after three times liquor returning,it increased to 12.67%,much higher than brut wine and aging roselle mead.So Liquor returning fermentation has obvious function in increasing aroma components of roselle mead,but the retruning time should less than three times becous of the acids.(2)Along with the increasing of liquor returning propotion,the esters and alcohols of roselle mead increased at frist and then decreased.When the liquor returning propotion is 10%,the esters Accounting for 5.96%of all aroma components,when the liquor returning propotion is 15%and 20%,its Accounting for 6.85%and 11.27%of all aroma components.But along with the liquor returning times increase,The acids of roselle mead increased.When liquor returning propotion is 15%,the acids Accounting for 7.73%,and when liquor returning propotion increased to 20%,the acids Accounting for 9.96%。So we chose 20%as liquor returning propotion.3.Anti-oxidative Effects of roselle meadRoselle mead have the ability of eliminating DPPH,superoxide anion(O2-·)and hydroxyl radical(· OH)The mean ability of eliminating DPPH is 55.24%,the ability of eliminating superoxide anion is between 9.44%and 36.64%,and the ability of eliminating hydroxyl radical is 70.57%.Overall,roselle mead has good oxidative stability.Correlation analysis on polyphenols,flavonold,anthocyanin and oxidative stability of roselle mead indicate:There was positive correlation between polyphenols and the ability of eliminating superoxide anion(r=0.769),and there was significant positive correlation between polyphenols and the ability of eliminating hydroxyl radical(r=0.966)。There was little bit of correlation between flavonold and the ability of eliminating superoxide anion and hydroxyl radical.And there was no correlation between anthocyanin and oxidative stability of roselle mead.