Bioactive compounds of mulberry fruit and assessment of the effect of Saccharomyces cerevisiae strains on the quality of mulberry wine products

In the winemaking process, yeast strain plays a crucial role in the quality of the wine products. Therefore, this study aimed to screen the phytochemical compounds from mulberry fruits and assess the effect of three commercial yeast strains (Saccharomyces cerevisiae var. burgundy, kyokai and montrachet) on the quality of mulberry wines. The results showed that mulberry juice was a rich source of phytochemicals compounds (tannins, flavonoids, anthraquinones, steroids, terpenoids and alkaloids). Yeast strains had a significant effect on oenological parameters, total anthocyanins, phenolics and flavonoid contents and antioxidant activities (DPPH and FRAP assay) of mulberry wines (p0.05). The total soluble solids contents continually reduced while the percentage of alcohol contents consistently increased after 24 days of fermentation. The total soluble solids, pH values and titratable acidity of three mulberry wines were in the range of 5.80±0.06 – 6.00±0.06°Brix, 3.23±0.01 – 3.35±0.01 and 1.06±0.01 – 1.12±0.040% CAE, respectively. Mulberry wine fermented by S. cerevisiae var. burgundy (MWB) had the highest alcohol content (7.80±0.17% (v/v)) and acceptance scores (4.27±0.45 points). Moreover, MWB had the highest antioxidant activities due to the presence of the total anthocyanins, phenolics and flavonoid contents in mulberry wine. Cyanidin-3-O-glucoside (C3G) and cyanidin-3-O-rutinoside (C3R) were two major anthocyanins in mulberry wines. The C3G contents ranged from 0.14±0.01 – 0.38±0.01 mg/100 mL, while C3R ranged from 0.15±0.01 – 0.49±0.01 mg/100 mL. Therefore, this could be considered that S. cerevisiae var. burgundy had the potential yeast to produce quality mulberry wine as a healthy alternative product. Mulberry exhibited good antioxidant activity of anthocyanins and other phenolic compounds.