Study On The Change Of Polyphenols In The Fermentation Process Of Hanfu Apple Wine

Apple is a fruitification of Rosaceae,native to the Middle East and Central Asia,which is introduced into China in the middle of the nineteenth Century.Apple is one of the top four fruits around the world,whose planting area has reached 2.5 million hectares in China.Apple is rich in carbohydrates,vitamins and trace elements.Hanfu apple is a kind of high quality breed which is able to resist cold.It is widely consumed for its profuse nutrition,pleasant aroma,also crisp,juicy and mellow tasty.Due to the high quality,the planting area of Hanfu apple is continually enlarged,leading to a relative low selling price.It seems that the optimum selection for farmer to increase their profit is to process Hanfu apple into apple wine.Apple wine contains polyphenols,a very important active ingredient,which be provided high nutritional value.Until now,research on further products of Hanfu apple barely exists,and there is no analysis or report which is directed at transformation of polyphenol content and antioxidant capacity of Hanfu apple wine.Therefore,this experiment taking Hanfu apple as test material,focus on studying change rule of Hanfu apple wine’s polyphenol by observing the fermentation process which provide theoretical evidence for the manufacture of apple wine.During the fermentation of Hanfu apple,the writer investigates the fermentation rules of total sugar,alcohol content,pH value and color of zymotic fluid by observing its reaction to different antioxidants(sodium chloride,lysine,vitamin C,citric acid,glucose oxidase)apple wine.The result as following:The total sugar shows a downward trend during the 20 day fermentation period,drop off about 2.2%from first days to 15th day,and it almost has no change later.So it is concluded that antioxidants have little impact on sugar.The alcohol strength shows an uptrend.It raise over 8.0° from the first day to fifth day.For the sample which is not added antioxidants and added sodium chloride,lysine,the alcohol reached 8.5°.pH value fluctuated around 4,it is no effect on fermentation.In the prophase of fermentation,it shows dark brown normally.After add Vitamin C,the zymotic fluid appears yellow and the color is better.In mid-term,there almost no difference among samples,shows yellowish-brown.At the last phase,it presents straw-yellow.After add lysine,it change into buff one.Writer sort these sample according to level that change sample zymotic fluid from dark yellow to pale yellow successively,vitamin C,sodium chloride,raw juice,glucose oxidase,citric acid and lysine.Hence the antioxidant has a certain influence on zymotic fluid during the fermentation process.Polyphenols is the main nutritional components of the Hanfu apple.That is also why we focus on studying the change and influence by adding different antioxidants during the fermentation phase.The results indicate that the total phenols of Hanfu’s fumet 297.543mg/L.During fermentation process,the overall trend of total phenolic is:decrease at the beginning then increase,peaking at fifth day,before decreasing until the end phase.The initial content of sodium chloride is 374.653mg/L,while the maximum reach 449.588 mg/L,and at the end of experience,it is 176.202 mg/L.According to the amount of phenols content from high to low,writer order these as below:Vitamin C,sodium chloride,glucose oxidase,antioxidant,citric acid,and lysine.And then writer analyze 4 polyphenols,Lv Yuan acid,caffeic acid,catechin,phloretin.At the initial stage,the content of Chlorogenic acid is about 90mg/L,the content of caffeic acid is 5-10mg/L,the content of catechin is about 8mg/L,and the content of phloretin is about 2mg/L.Among the final fermentation products,the one adding sodium chloride has highest content in chlorogenic acid,catechin,and phloretin.It still respectively hold chlorogenic acid 24.84mg/L,catechin 2.28mg/L,phloretin 3.95mg/L.It lead to highest caffeic acid content by using glucose oxidase as antioxidant,reaching 11.66mg/L.In the process of fermentation,we analyze the antioxidant activity of zymotic fluid through adding different antioxidants to make Fuhan Apple wine.The results showed that the DPPH removal capacity of all samples shows a downward trend,from 90%to about 80%.The antioxidant capacity of T-AOC becomes stronger in the first three days.The ABTS indicate that its antioxidant capacity act kind of volatility in the fermentation period,entered a stable state after ending fermentation into the mellow stage.Both the DPPH and ABTS methods of the 3 methods suggest that the antioxidant capacity of vitamin C is the strongest,and the T-AOC method showed that the antioxidant capacity of sodium chloride is the best.Thus,it will be better choice,if we use sodium chloride as antioxidant.