| Wine was an international drink which was popular for its high nutritional and health benefits.However,due to its complex and diverse composition,it was changable and difficult to maintain stability.And seriously affect its quality,Therefore,maintaining or improving the stability of wine was an important problem to be solved in wine production,especially in the process of storage and consumption.Sulphur dioxide(SO2),a traditional antioxidant,played an important role in stabilizing the color and antiseptic properties of wine.However,with the increasing awareness of health care,the toxic and side effects of SO2 had attracted much attention.Besides,the addition of SO2 masked the natural mellowness of wine.Slightly higher dosage produced obvious irritating and sour sensation,which further affected the taste and quality of the wine.Actually,the high volatility wine of SO2 deteriorated quickly once it was placed in the open.Therefore,the exploration of a new type of stabilizer with no toxic and side effects was of great practical significance for stabilizing and improving the quality of wine and promoting the development of the wine industry.In this paper,we investigated the factors affecting the stability of wine by measuring the changes of physical and chemical indicators of different red wines under different storage conditions with time.Using the preferred antioxidant grape seed extract and Vc as materials,the effects of two antioxidants and grape seed extract mixed with low concentration SO2 were determined by antioxidation test to measure the stability of red wine.Through the Self-built open condition,the physical and chemical indicators of Syrah dry red wine(Sample 1),Merlot dry red wine(Sample 2)and Cabernet Sauvignon dry red wine(Sample 3)under different storage conditions were detected.The changes and characteristics of these red wines were explored.The results showed that with the prolongation of time,the clarity,alcohol content,free SO2,total phenol and DPPH clearance rate showed a downward trend while color,volatilization,the content of acid,total acid and polysaccharide were on the rise.Under low temperature conditions,it was beneficial to slow down the changes of various physical and chemical indicators and antioxidant activities of wine.The difference of the indexes of wine sample 3 was the most significant,so it was selected as the follow-up test wine sample.wine sample 3 was chose as the test material,grape seed extract and Vc worked as antioxidant,the stability of red wine under open conditions was studied,compared with the wine sample without antioxidant(Ck)and adding different concentrations SO2 wine samples.Studies have shown that the addition of grape seed extract improved the stability of the wine.When the addition amount reached 100mg/L,the effect was the best,which effectively inhibited browning of the wine,Browning is reduced by 28% compared to Ck,The redox potential of the wine is reduced by 30 mv,DPPH free radical scavenging rate,inhibition of-OH capacity and total antioxidant capacity were 88.58%,66.14U/mL,and 52.26U/mL,Compared with Ck,it increased by17.37%,17.47U/mL and 30.62U/mL.Compared with 100 mg/L SO2,it was increased by 12.95%,10.75U/mL,and 12.66U/mL,respectively lowered the redox potential of the wine,and had better antioxidant activity.The Vc-added wine sample showed a good anti-oxidation effect in the early stage.With the prolongation of time,Vc played a role in promoting oxidation,accelerated the oxidative browning of the wine sample,and improved the redox potential of the wine.But,it could not be used alone as an antioxidant.In addition to the insignificance of alcohol and the addition of antioxidants,the changes of other physical and chemical indicators were related to the addition of antioxidants.The addition of antioxidants enhanced the stability of the wine.The resistance of the selected antioxidants was studied by the normal temperature and normal pressure natural oxidation method and the(38±1)accelerated oxidation test method,?Using wine sample 3 as raw material,use low concentration SO2 with grape seed extract,use Wine sample Ck1 without antioxidant and Compared with the wine sample Ck2 with only 100 mg/L of SO2 as control group,added wine samples were evaluated for their effects on physical and chemical indicators and sensory indicators after 3 months of storage at room temperature and pressure.Evaluate their effects on physical and chemical indicators and sensory indicators of wine,and combine the optimum concentration for accelerated oxidation test.The results showed that the combination of SO2 and grape seed extract could improve the stability of the wine,and the grape seed extract enhanced the antioxidant effect of SO2.Effectively reduce the browning degree of the wine,inhibit the oxidation of phenolic substances in the wine sample,and improve the stability of the tartar of the wine,The microbial stability is good,the total number of colonies and the detection requirements of pathogenic bacteria are in line with national standards,and there is no adverse effect on the physical and chemical indicators and sensory quality of the wine samples.Comprehensive sensory quality evaluation showed that A2B1(30mg/L SO2+50mg/L GSP)was the best treatment for wine.Accelerated oxidation test of A2B1 with Ck2(100mg/LSO2)as control,Two groups of wine samples were accelerated for one month at(38±1)?.Compared with Ck2,It was found that the A2B1 complex allowed red wine to keep stable at(38±1)? for one month without deterioration.Compared with Ck2,it could effecticely inhibit the browning of red wine,the wine was still stable.The wine sample,added with SO2,had obvious browning and turbidity.From these result,it could be seen that if the complex was added into the wines of this study,which could be stored under normal conditions and their stability was significantly better than those of ordinary wines.In summary,the variations and characteristics of wine indexes were found through the self-built open condition.Using the preferred antioxidant grape seed extract and Vc as materials,the effects of two antioxidants and grape seed extract mixed with low concentration SO2 were determined by antioxidation test to its effects on the stability and quality of red wine.Also,its superiority to wine stability was further verified by accelerated oxidation test. |
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