Effect of selected yeast on physicochemical and oenological properties of blueberry wine fermented with citrate-degrading Pichia fermentans

Blueberry wine has an excessively sour taste due to the presence of high-level of organic acids. Pichia fermentans JT-1-3 with a strong ability to degrade citric acid was selected for blueberry wine production in this work. The flocculation of JT-1-3 in comparison with two S. cerevisiaes strains was evaluated. Then citric acid degradation of JT-1-3 was assessed in synthetic media with different citric acid/glucose ratios under shaking or static conditions. Finally, JT-1-3 was inoculated in blueberry juice for fermentation. The results confirmed that JT-1-3 had appropriate flocculation and consumed citric acid and glucose greatly. In final wines, 6.25% (v/v) alcohol was achieved with 1.83% (w/w) residual sugar. Compared with juice, citric, malic and tartaric acids declined significantly by 43.35%, 35.29% and 44.68% in wine, respectively. 2-phenylethanol, ethyl 9-hexadecenoate, ethyl decanoate were the main volatiles in blueberry wine and most esters contributed to the aroma with high odor activity values. Sensory evaluation showed that wine produced by JT-1-3 imparted improved taste with lower acidity, bitterness and hotness perceptions compared with S. cerevisiae fermentation. This work revealed that JT-1-3 had a great potential to be applied for blueberry wine fermentation along with deacidification.