Study On Brewing Technology Of Fig Wine And Evaluation Of Antioxidant Activity

Fig is good in food and medicine.But its pericarp is thin,and its fruit is juicy,perishable and poorly stored.Wine making is the main direction of the fruit processing industry.In order to increase the use of fig fruit,using fig cultivar"Ma Si Yi Tao Fen"as the experimental material in this study,the best strains of dry yeast was selected,enzymolysis conditions and fermentation process parameters was optimized,the changes of active components and antioxidant activities during enzymolysis and fermentation period were analyzed.Finally,the best brewing technology of fig wine was determined,its main nutritional components,quality indexes and antioxidant activities were analysised.The main conclusions were as follows:(1)Through single factor and response surface methodology(RSM),and considering the convenience of actual operation,the best condition of enzymolysis of fig was determined:cellulase addition amount 1.56%,pectinase addition amount 0.28%,enzymolysis temperature 53℃,and enzymolysis time 90 min.(2)The dry yeast strain"RV171"was determined as the appropriate fermentation strain of figs.Through single factor and response surface methodology(RSM),and considering the convenience of actual operation,the optimal fermentation technological parameters were determined:dry yeasts inoculation amount 0.03%,potassium metabisulfite addition amount 83mg/kg,fermentation temperature 28℃,fermentation days 8 days.(3)The total polyphenol content>total flavonoid content>vitamin C content in the fig juice,and the content of the three components increased during the enzymolysis period,among which the biggest increase was total flavonoids.Total antioxidant capacity,hydroxyl radical inhibition rate and DPPH·scavenging rate also increased during enzymolysis period,among which the biggest increase was hydroxyl radical inhibition rate.Total polyphenols content,total flavonoids content,vitamin C content had obvious positive correlation(R~2≥0.85)with total antioxidant capacity,hydroxyl radical inhibition rate,DPPH·scavenging rate,respectively.(4)The total polyphenol content>the total flavonoid content>the vitamin C content,the content of the three components raised first and then decreased in the wine during the fermentation period.In general,the content of the three components increased,among which the biggest increase was vitamin C.The total antioxidant capacity,hydroxyl radical inhibition rate and DPPH·scavenging rate showed the same trend,such as the above three components,among which the biggest increased was total antioxidant capacity.The content of three components had low correlation with total antioxidant capacity and DPPH·scavenging rate,respectively,but with hydroxyl radical inhibition rate had obvious positive correlation(R~2≥0.81).(5)The total polyphenol content,total flavonoids content,vitamin C content,total antioxidant ability,hydroxyl radical inhibition rate,DPPH·scavenging rate in fig wine were determined.Compared with fig fruit,they increased by 15.42%,54.71%,34.89%,34.87%,12.97%and 5.10%,respectively,among which the biggest increase was total flavonoids content.(6)The fig wine was evaluated.It had a higher sensory score(82 points),including 8 points of appearance,25 points of aroma,41 points of taste,8 points of typicality.Other indexes such as alcohol content,total acid content,volatile acid content,total sulfur dioxide content,dry extract content,lead content,total colony group,coliform group,staphylococcus aureus and salmonella all complied with national standards GB2760-2014 and NY/T1508-2017.