Study on Optimization of Process and Related Index Changes of Low Alcohol Germination Buckwheat Wine

Using the buckwheat which has germinated for 72 h as raw material,the low-alcohol buckwheat wine was produced by liquid fermentation. In the germination stage,the effects of culture temperature,illumination time and the type and concentration of salts on the total content of flavonoids and phenolic acids were investigated. In the saccharification stage,the effects of saccharification temperature,saccharification time and glucoamylase addition on dextrose equivalent (DE) were investigated. Based on single factor experiments,response surface method was used to optimize the culture conditions and saccharification process of germination buckwheat,and the optimal parameters were then selected. The results showed that the optimal germination conditions of buckwheat were as follows:KCl concentration of 20 mmol/L,culture temperature of 25℃ and illumination time of 4 h. Under this germination condition,the total content of flavonoid in germinated buckwheat was (14.70±0.08) mg/g,and the total content of phenolic acid was (16.78±0.05) mg/g. And the optimal saccharification process were as follows:Glucoamylase addition of 3%,saccharification temperature of 58℃ and saccharification time of 3.5 h. Under this condition,the DE value was 24.13%±0.02%. After the optimization of germination and saccharification process,the fermented germinated buckwheat wine for 4 d was 8.83%±0.11% vol,which had more mellow taste. The total content of flavonoid in the germinated buckwheat wine was (1.458±0.015) mg/100 mL,the total content of phenolic acid was 24.93±0.01 mg/100 mL and the total content of γ-aminobutyric acid was (12.33±0.012) mg/100 mL,DPPH free radical scavenging rate was 85.22%±0.01%. Therefore,the germination of buckwheat wine tastes well and its nutritional value is also improved,which provides a new theoretical basis for the study of low-alcohol buckwheat wine.