Research On Process Optimization And Quality Analysis Of Fermented Onion Wines

Onion(Allium cepa L.)belongs to the genus Liliaceae and is widely cultivated in China.It contains abundant sulfur compounds,flavonoids,polysaccharides,prostate compounds and trace elements.It has been reported that onion wines have the effects of lowering blood sugar,preventing cardiovascular diseases,and resisting oxidation,but their productions or brewing processes are not mature enough.In this experiment,purple onion and Cabernet Sauvignon grape were used as raw materials to optimize the brewing process of onion wine,and the quality of onion wine was analyzed to provide reference for the industrialization of onion wine.The main results are as follows:(1)The microwave parameter of alliinase inactivation in onion was 560 W for 4.5 min.The single-factor test and orthogonal experiment optimization showed that the brewing process parameters were selection of CECA for yeast species,addition of 150 mg/L yeast,mixed onion juice and grape mash,and onion mixing ratio of 20%.It provided references for the industrialization of fermented onion wine.(2)The quality of the optimized onion wine was analyzed.The contents of reducing sugar,alcohol and the dry extract of the onion wine were 1.65 g/L,9.0%vol and 19.78 g/L,respectively.The basic physicochemical indexes of the onion wine met the national standard GB/T 15037-2006 Wine.Compared with Cabernet Sauvignon dry red wine,the color depth of the onion wine reduced,the hue increased,the brightness increased,the color more red and yellow;the contents of total anthocyanins,flavonoids and polysaccharides all increased,but phenols reduced;ABTS and DPPH radical scavenging capacities both decreased slightly.The content of aroma components in the onion wine was 212.84 mg/L(47 kinds),including 51.43mg/L(21)esters,9.76 mg/L(8)acids,138.04 mg/L(6)alcohols,1.05 mg/L(6)ketones,11.22mg/L(3)sulfur organic compounds,0.36 mg/L(3)other species;monomer phenols 13.60mg/L(11);anthocyanin monomes 99.133 mg/L(19),of which the content of malvidin-3-O-glucoside was the highest.The sensory score of the onion wine was 80.03 points,with the appearance of purple-red,clear and translucent,and the aroma of pleasant fruit and mellow and elegant onion.It provided scientific basis for the quality of fermented onion wine.(3)The correlations of the color indexes of the fermented onion wine were analyzed.The CIE parameters L*,a*,b* were found to be highly correlated with color depth and hue(|r|>0.8).The correlations between the contents of phenolic compounds and polysaccharides and the antioxidant capacities of fermented onion wines were analyzed.The contents of anthocyanins,flavonoids,phenols and polysaccharides in onion wine had significant correlations with ABTS and DPPH radical scavenging abilities(P<0.01).The contents of some monomers were significantly correlated with ABTS and DPPH free radical scavenging abilities(P<0.01 or P<0.05).It provided a scientific basis for exploring the mechanism of antioxidant capacity of fermented onion wine.