Study On Characteristic Flavor Analysis And In Vitro Antioxidant Activity Of Mulberry Wine During Fermentation

Mulberry fermented wine is a fruit wine prepared by microbial fermentation and suitable for most young people to drink.It is a kind of drink with extremely rich functional and nutritional value for medicine and food.Not only can the functional nutrients of mulberries be fully retained,but it also makes up for the shortcomings of mulberries that are seasonal and difficult to store,and the wine become an emerging functional food with great development potential.In this experiment,the mature and intact"Qiangeli"mulberry fruit in Xinjiang region was selected as the raw material of fermented wine,and the activated low-temperature-tolerant yeast LABA yeast at a concentration of 0.2 g/kg was inoculated at20-22?to enter the main fermentation stage.In the fermentation process,we took samples to determining and analyse of the basic physical and chemical indicators,functional nutrients,and antioxidant capacity,which provided a theoretical foundation and basis for mulberry wine to fully retain its functional nutrients and make it become the best functional drink.The main research findings are as follows:(1)The p H value of mulberry fermented wine has been in a downward trend during the early stage of fermentation,and the p H value remained unchanged at 4.37 after 264 hours.The total acid content has been increasing during 120 h of the whole fermentation,and there is no significant change when its content reaches 11.3±0.23 g/L after 120 h.During the fermentation process,the reducing sugar of mulberry wine and the residual sugar changed in the same trend.As the fermentation time increased,the sugar content decreased.After 216hours of fermentation,the residual sugar content remained stable,along with the alcohol content continued to increase with the extension of the fermentation time,what is consistent with the changing law of sugar content in fruit wine.(2)The total content of 16 different types of amino acids which were detected in the main fermentation process of mulberry wine in this experiment was significantly higher than that of commercial mulberry wine of different brands,and the content decreased first and then increased during the fermentation process.After 240 h,there was a slow downward trend,indicating that the main fermentation of mulberry wine to 240 h is beneficial to the retention of amino acids in mulberry wine.(3)The content of total flavonoids,anthocyanins and proanthocyanidins in mulberry fermented wine showed a dynamic trend of first decline and then gradually stable during the main fermentation process.The overall change of the total phenol content is a downward trend.Generally speaking,the mulberry wine has a higher active ingredient content in the later stage of the main fermentation than in the fermentation process,which is more convenient for drinking.Compared with commercial mulberry wine,the content of total flavonoids and anthocyanins is prominent,but the content of proanthocyanidins is low.(4)During the main fermentation process of mulberry wine,a total of 56 flavor components were identified,mainly including 30 esters,whose total relative content accounted for more than 90%of volatile flavor substances,and belonged to the main flavor components of mulberry wine.The main aroma substances in the analysis mainly include 13kinds,mainly fruity and floral aromas.The flavor substances are the most abundant after 120h of fermentation,and their content is stable after 120 h.(5)The antioxidant capacity of mulberry wine after fermentation is significantly higher than that of mulberry pulp before fermentation,indicating that its total antioxidant capacity has been well improved after main fermentation.Mulberry wine had the best total antioxidant effect when the fermentation progressed to 120 h,which may be related to the increase in the total phenol content of the wine sample during this fermentation stage.The effect of mulberry wine on free radicals changes irregularly during the fermentation process,but the change trend is similar,and the effect is best at 24 hours of fermentation,which is similar to the change law of anthocyanin content in fermented wine.It shows that the higher the anthocyanin content in mulberry wine,the better its cleaning effect on ABTS~+free radicals and DPPH free radicals,and the compounds that affect the ability to scavenge these two free radicals have a strong correlation.By measuring the fermentation process indicators,nutrients and functional factors,flavor substances and antioxidant activity in the main fermentation process of mulberry wine,it can be seen that the functional nutrient content of mulberry fermented wine in this experiment is higer compared with the commercial mulberry wine of different brands.The basic indicators of mulberry wine in the main fermentation process have basically tended to balance around216 hours.In order to comprehensively consider the flavor characteristics of fruit wine and functional activities such as antioxidants,and obtain the best functional drink,it should be considered to stop its main fermentation process when the fermentation process of mulberry wine was during the period of 216 h-240 h.