Research And Quality Characteristics Of Fig Wine

Fig,a woody plant of Moraceae family,is rich in polysaccharides,flavonoids,vitamins,minerals and enzymes.The fig fruit exhibits various activities such as cough relieving,antioxidation,anticancer etc.Due to short harvest seasonality and shelf-life and extremely perishable at room temperature,it is significant to improve the potential utilization value of figs through high-output processing.In this paper,the physicochemical indices,aroma components and antioxidant properties of fig wine were analyzed in order to explore the effects of different raw materials,pretreatment methods and exogenous acids on the qualities of fig wine.Meanwhile,the fig sparkling wine was prepared to broaden the processing way of fig fruits.The main results are as follows:1.The effect of heat treatment on the fermentation indexes of fig wine was studied.Both fresh and dried fig wine exhibited good fermentation performance.Compared with dried fruit wine,the wine fermented with fresh fruits showed a shorter fermentation period,less changes in pH value and total acidity.During fermenting,there was no significant difference on the content of polyphenols(p>0.05),while the contents of flavonoids and anthocyanins increased(p<0.05).The increased flavonoids and anthocyanins in the wine fermented with heat treated fruit were less than that in the control groups.2.After fermentation,the physicochemical index in the four fig wines was total sugar 1.6-3.4 g/L,alcohol 10.6%-11.6%,dry extract 24.6-28.7 g/L,total acidity 4.5-5.5 g/L,pH value 3.54-3.75,total SO2 68.7-79.7 mg/L,and volatile acidity 0.63-0.82 g/L.All of above indexes conformed to the requests of NY/T 1508.The fresh fig wine had lower total sugar,higher alcohol,indicating a better fermentation environment for yeast metabolism.By the heat treatment of fruit pulp,the dry extract in the resultant wine was increased while the total SO2 in which was decreased.There was no significant difference in volatile acidity(p>0.05)in all the wines.3.The GC analysis results showed that the main volatile substance of fig wine was isobutanol,isoamyl alcohol and active amyl alcohol,respectively.The highest content of isoamyl(284.03 ± 2.97 mg/L)and active amyl(88.97 ± 2.33 mg/L)alcohol were found in the fresh fruit fermented with heat treatment fruit pulp;however the highest content of isobutanol(146.41±2.36 mg/L)was in the wine with fresh fruit.Eight higher alcohols were detected in fresh fruit wine including n-propanol,n-butanol,iso-butanol,n-amyl alcohol,active amyl alcohol,isoamyl alcohol,furfuryl alcohol,?-phenylethanol.In dried fig wine 2,3-butanediol was found and the n-propanol,n-butanol,n-amyl alcohol and P-phenylethanol in the fresh fruit wine did not showed.Less acetic acid content was in fermented wine by dried fruit and heat treated pulp.Propionic acid was not detected in fresh fig wine while hexanoic and heptanoic acids were not detected in dried fig wine.By heat treatment,the methanol content in fig wines decreased significantly(p<0.05).4.The contents of total polyphenols and flavonoids in fig wine fermented from heat-treated raw materials were lower than that in the contrast,and the antioxidant capacities in the wine reduced as well.The total polyphenol content in fig wine was significantly correlated with the scavenging ability of O2-·(r=0.027,p<0.05)and FRAP value(r=0.048,p<0.05).The flavonoid content was significantly correlated with the scavenging ability of ·OH(r=0.019,p<0.05).Rutin and protocatechuic acid were the highest monomer phenols in fig wine.5.Different exogenous acid were added to prepared fig wine.Compared with citric acid,the pH value of fig wine with lactic acid was more obvious during fermentation.Succinic acid was the highest organic acid in fig wine.When the addition of exogenous acid was 2 g/L,the total acid and organic acid content in fig wine were too high,with heavy acidity and poor typicality.It was found that the balance sour,mellow mouthfeel,excellent typicality and the best sensory evaluation standard were good adding 1 g/L lactic acid.6.Based on the extraction from fresh and dried fruit via heat treatment before fermentation,the sparkling wine with secondary fermentation in the bottle was prepared.Different base wine and aging had no significant difference in the maximum foam height,bubble foam stability(p>0.05).After aging,the sparkling wines tasted mellow with more delicate foam and stronger mouthfeel were obtained.