Study On The Technology Of Red Raspberry-Blueberry Compound Fruit Wine And Analysis Of Its Aroma Components

In this study,red raspberry and blueberry were used as raw materials to study the processing technology and clarification process of red raspberry-blueberry compound wine,and the changes of active ingredients and antioxidant activity of wine during aging were studied.The changes in aroma components were studied.The main research contents are as follows:(1)The processing technology of red raspberry-blueberry compound wine was studied.The single factor test was carried out on the three factors of fermentation temperature,yeast liquid addition and sugar content with alcohol content as the index.The best technological conditions were as follows: The fermentation temperature was 28?,the yeast liquid addition amount was 5%,and the sugar content was 200 g/L.The optimal process conditions after orthogonal test were as follows: fermentation temperature was 28?,initial sugar content was 220 g/L,yeast liquid addition amount was 4%,and the obtained alcohol degree was 13.95 %vol.(2)The clarity of fruit wine is an important factor to measure the quality of wine,and the effect of different clarification methods on the light transmittance of compound wine was studied.The results showed that the clarifying agent had the best clarification effect,followed by freezing and clarification,and the natural clarification effect was the worst.The clarification effect of chitosan and bentonite was better in the four clarifiers.The best clarification conditions were obtained by the combination of response surface optimization: composite clarifier ratio of 9:5,water bath temperature of 47?,water bath time of 57 min.Three parallel experiments were carried out,and the light transmittance of the obtained composite wine was 92.36%,which was basically consistent with the predicted value.(3)The red raspberry-blueberry compound wine had different aging time,and its active ingredients and antioxidant capacity were also changing.The results show that the functional ingredients and antioxidant activities of the redberry-blueberry compound wine are constant after 60 days of aging.When the red raspberry-blueberry compound wine was aged for 60 days,the total phenolic,anthocyanin and flavonoids decreased by 34.85%,25.60% and 29.87%,respectively.The DPPH,hydroxyl radical scavenging ability and superoxide anion radical scavenging capacity decreased by 24.9%,36.5%,28.2%,respectively.After the aging of the wine,the multi-functional components in the wine showed a downward trend compared with the end of the fermentation,and the longer the aging time,the greater the decline.(4)The aroma components after the main fermentation,post-fermentation and aging of the wine were determined by gas chromatography-mass spectrometry.The results showed that the total volatile substances content was 87.72%,83.89% and 78.24% after main fermentation,post-fermentation and aging,showing a downward trend;alcohols and esters had a significant influence on the aroma components of wine.Esters accounted for 15.37%,22.29% and 22.39% of the volatile components respectively after main fermentation,post-fermentation and aging,showing an upward trend.It indicates that the longer the fermentation time,the more the ester will increase,but the less the total content of volatile component will be.