The Study Of Low-alcohol Whey Wine

With the cheese market expansion, the application of whey gradually causes attention of the society. Whey wine is low alcohol drink with a fresh and slight palate, which is fermented by yeast and lactobacillus. The ethanol content of whey wine is between 2%～5%.This study selected kluyveromyces lactis, fermented with saccharomyces cerevisiae as co-culture, after the optimization of fermentation conditions, ethanol content was 2.41% in 48 h. Comparing to the past fermentation, the paper used two strains yeast,overcoming the unstable relationship and long fermentation time.Methods adopted by the Subject and the main research results are as follows:(1) After initial screening, gas processed quickly and high lactose utilization strain were selected.After double scereen,kluyveromyces lactis fermented whey had rich alcohol, good flavor and no pungent acid, which could be used as target strain. Strain growth curve determination results show that the logarithmic phase of saccharomyces cerevisiae B2 in 4-14 h, kluyveromyces lactis Q10 in 6～12 h, the ethanol tolerance of saccharomyces was higher than kluyveromyces lactis.(2) According to the single factor experimental results, choosing four factors:strains, culture temperature, initial pH, speed ratio to do response surface optimization and regression model R2 was 0.9577, the interaction effect of speed and pH was significant. Results showed that whey powder concentration of 10%, inoculation quantity was 5%, kluyveromyces lactis and saccharomyces cerevisiae strain ratio of 1:5, temperature 29℃ , pH 6.0, speed 160 r/min, the actual yield of ethanol was 2.41% after 48 h.(3) The soluble protein content in whey was decreased as well as the analysis of free amino acid content. Ultra high performance liquid chromatography of free amino acid test wed that saccharomyces cerevisiae fermented whey alone, serine and cysteine increasedificantly, when the presence of kluyveromyces lactis, the content of free amino acids in were all decreased.