| Mulberry wine takes mulberry fruit or mulberry juice as raw material and produces alcohol and various metabolites after yeast fermentation.The final mulberry wine is rich in nutrition and has certain effect and health care.Mulberry is extremely intolerant of storage but has high nutritional value.It will be beneficial to study the change of properties of frozen mulberry during processing.In this paper,frozen mulberry is used as raw material,to study the thawing treatment of frozen mulberry,the extraction process of frozen mulberry and the fermentation process of frozen mulberry fruit wine,in order to provide theoretical basis for the production of mulberry wine by fermentation of frozen mulberry.The results of this research are as follows :At low temperature thawing,room temperature thawing,ultrasonic thawing and microwave thawing treatment-20? frozen mulberry fruits,the final results showed that the microwave thawing rate was high and the juice loss was low.At room temperature,the temperature difference inside and outside mulberry fruit is large,the juice loss rate is higher,the thawing rate is faster;Ultrasonic treatment will also lead to the temperature difference inside and outside mulberry fruit,affecting the thawing effect;longest thawing time.Under the four treatment conditions,the difference of juice yield was small.To improve the juice yield of mulberry fruit,pectinase was added to the mulberry juice extraction test.The mathematical regression model between the juice yield and the extraction process parameters of mulberry juice was established by response surface test.The optimum extraction process parameters were as follows: adding 2.5% pectinase and the processing time is 2.5 h,in 50?environment,the final juice yield was 64%.By comparing the alcohol content of mulberry wine fermented under different fermentation conditions,the suitable range of fermented fruit wine was determined.The optimum fermentation conditions of mulberry wine were obtained by mathematical regression model between alcohol content and fermentation conditions:the initial sugar content was adjusted to 25 °Brix,and the yeast with 2% content was added,the fermentation temperature is 27?,The alcohol content of fermented mulberry wine was 10.25%vol.The changes of physical and chemical indexes during the fermentation of frozen mulberry wine can determine the fermentation state and fermentation degree of fruit wine and the nutritional quality of the final fermented mulberry wine.During the fermentation process,the total sugar in the fermentation broth decreased gradually,the consumption rate was fast in the early stage,the consumption rate was gentle at the end of fermentation,the p H value in the fermentation broth decreased first,the total acid increased first and then decreased.Determination and Analysis of Flavor Substances of Mulberry Juice and Fermented Mulberry Wine extracted.The results showed that 27 and 41 kinds of flavor substances were detected in mulberry initial fermentation broth and mulberry wine,among which the kinds and contents of acids and esters in fruit juice were abundant,and the kinds and contents of alcohols and esters in mulberry wine were the most abundant.It shows that mulberry has changed greatly through fermentation.The total phenol content,DPPH radical scavenging ability,ABTS radical scavenging ability and total reduction ability of mulberry wine during fermentation showed a trend of rising first and then decreasing.The final mulberry wine retained more phenolic substances,antioxidant activity will be strong,there is a correlation between total phenol content and antioxidant activity. |
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