Analysis Of Terpenes In Mulberry And Fermentation Of Mulberry Wine

Fructus Mori is a kind of fruit with rich nutrition.The healthy function of mulberry products is constantly recognized and acceptted to public.Mulberry has the characteristics of high sugar,with bright color,elegant aroma,and stable pigment content,which is an excellent raw material for fermentation.Mulberry wine preserve the nutritional value and functional ingredients of mulberry,which not only overcome the problem of storability of mulberry,but also improve its economic benefits.In this research,the terpenoids in different varieties of mulberry were studied,and the changes in the growth process of mulberry were analyzed,as well as the divergence between different varieties.To compare the inhibitory effect of different antibacterial agent on microorganisms in mulberry to replace sulfur dioxide.At the same time,different clearing agents were selected to clarify the mulberry wine after fermentation.The changes of aroma compounds in mulberry wine during fermentation were analyzed,and the aroma compounds in different varieties of mulberry wine were compared.The main research conclusions were as follows:1.During the development of mulberry,different varieties of mulberry had different physical and chemical properties,among which "Dashi","Siji" and "Hongguo" had similar changes.By HS-SPME-GC-MS,31 kinds of terpenoids were detected in “Dashi”mulberry,among which 25 kinds of monoterpenoids and only 6 kinds of norisoprene were found.The content of monoterpenoids was the highest at 50% veraison and the lowest at post-veraison.Only 9 kinds of terpenes were detected in “Baizhenzhu” mulberry.The amount and content of terpenes gradually decreased during the growth process.Among different varieties of mulberry,the content of terpenoids in “Dashi” was the lowest,while that in “Siji” was the highest,and that in “Hongguo” was the highest.Among them,α-ionone and linalool are the main terpenes in mulberry.2.Calcium propionate,ε-polylysine and natamycin were selected as antibacterial agents instead of sulfur dioxide.The optimum concentration of Calcium propionate was0.8 g/L,1.0 g/L of ε-polylysine was selected as the optimum concentration of antibacterial agent.When concentration of natamycin was 0.4 g/L,antibacterial effect was equivalent to100 mg/L sulfur dioxide.0.4 g/L natamycin was selected to replace sulfur dioxide in the mulberry fermentation.Bentonite,PVPP and pectinase were used to clarify mulberry wine after fermentation.6 g/L for bentonite,0.8 g/L for PVPP and 0.8 g/L for pectinase.PVPP had higher clarity to mulberry wine,but the color loss was larger.Bentonite and pectinase had better clarification effect,and the effect of clarification time on chromaticity was relatively small.pectinase had shorter clarification time and reduced the loss of chromaticity.Pectinase had the advantages of shorter clarification time,less color loss,high efficiency.Therefore,0.8 g/L pectinase was selected to clarify mulberry wine.3.A large number of aroma substances were produced during fermentation.The fermentation process of “Dashi” mulberry was detected by HS-SPME-GC-MS.During fermentation,65 kinds of aroma substances were detected.The content of the aroma substances increased from 15749.12 μg/L to 82530.42 μg/L,increased by 5.24 times.The quantity of aroma substances increased from 56 to 63.Principal component analysis of aroma components revealed the changes and contributions of aroma components in the mulberry fermentation process.The aroma components of four varieties of mulberry wine were detected.The total content of aroma compounds in “Baizhenzhu” mulberry wine was 133953.76 μg/L,which was the highest among the four kinds of mulberry wine,in which esters accounted for80.00% and alcohols accounted for 12.97%.The total content of aroma compounds in“Siji” mulberry wine was 75419.07 μg/L,which was the lowest among the four kinds of mulberry wine,in which esters accounted for 64.21%,alcohols accounted for 23.79%.The highest content of acids in “red fruit” mulberry wine was 12405.11 μg/L,which was 3.03 times of “Baizhenzhu” mulberry wine.The results showed that the aroma components of different varieties of mulberry wine were different,and the contents of esters,acids,alcohols,aldehydes and ketones were different.