Study On Producing Nutritional Ftuit Wine By Fermenting Fresh Sugarcane Juice

Sugarcane is used as raw material for producing nutritional fruit wine, in order to developing circular economy of sugarcane and extending the chain of sugarcane industry. This is good for developing a new way to highly process sugarcane and the comprehensive utilization of bioresource. This study mainly achieved the following results:Saccharomyces cerevisiae 32481 is identified as the best strain for fermenting sugarcane fruit wine by screening experiments. Resistance properties’experiments with strain 32481 showed that the highest tolerance to the concentration of alcohol and sugar were 18%(v/v) and 50°x; the lowest tolerance to the acid were pH 2.0. Preferred Saccharomyces cerevisiae 32481 has high resistant to alcohol, sugar and acid.Using single factor experiments and Box-Behnken experiment design, the fermentation conditions of sugarcane fruit wine were optimized by response surface analysis. The results showed that the optimal conditions of sugar wine fermentation were fermentation time 4.5 days, liquid volume 60%(v/v), inoculum 18%(v/v), initial pH 4.95, temperature 26.5℃, ammonium sulfate 0.1%(w/v), potassium dihydrogen phosphate 1.2%(w/v) and initial sugar concentration 26.5 °Bx. Under the optimal conditions, the average value of alcohol concentration reached 14.15%(v/v) by fermenting sugarcane juice. By the analysis of variance, effect of four selected factors on the alcohol concentration is ranked from strong to weak:fermentation time> initial pH> fermentation temperature> initial sugar concentration.Applying the model equations of Logistic and Leudeking-Piret, kinetic models of growth of yeast, generating alcohol and consume of sugar were established. The results showed that the fitting degree of kinetic model predictions and experiment measured datas were 0.98333,0.97156 and 0.97227, respectively. Moreover, the average fitting errors were 1.406%,6.263%and 4.242%. According to the results, the models were fitting well and models’ feasibilities were proved. After fermentation, acid, bacterial content, alcohol concentration and residual sugar concentration were 7.325 g/L,10.2 g/L, 14.10%(v/v),35.130 g/L.Via single factor experiments and orthogonal experiment, the best conditions of Fed-batch fermentation for sugarcane fruit wine were determined: feeding time 2.5 d, feeding sugar concentration 29.0°Bx and feeding addition 35%(v/v). Under those optimal conditions, the alcohol concentration of sugarcane fruit wine, total residual sugar content and total acid content individually were 15.83%(v/v),38.388 g/L and 8.223 g/L. Besides, the alcohol concentration of Fed-batch fermentation was 12.27% higher than that of batch fermentation conditions. Through the variance analysis of orthogonal experiment results, the effect order of three factors was obtained:feeding time> feeding addition> feeding sugar concentration. Among them, feeding time had significantly effect on the alcohol fermentation of sugarcane juice.Sugarcane fruit wine was detected. The results showed that sugarcane fruit wine was rich in amino acids and minerals. Meanwhile, it complied with standards of fruit wine in NY/T 1508-2007 Green Food. The result also proved that sugarcane juice could be used for fermenting semi-sweet fruit wine, which is rich in nutrition and has fresh and pleasant wine odor with fragrant sugarcane smell.