Effect of potassium metabisulphite and potassium bicarbonate on color, phenolic compounds, vitamin C and antioxidant activity of blueberry wine

Abstract

In this paper, the effect of potassium metabisulphite and potassium bicarbonate post-fermentation addition on the bioactive compounds, color and antioxidant activity in blueberry wines was studied. This effect has been widely studied in grape wines but in blueberry wines are scarce. For this purpose, four different blueberry wines were elaborated and subjected to post-fermentation addition of potassium bicarbonate and potassium metabisulphite. Potassium bicarbonate was used to improve the organoleptic characteristics, reducing the acidity, and the potassium metabisulphite was used to maintain the stability of the wines over time, as preservative, antioxidant and antibacterial. On one hand, changes in the composition and characteristics of blueberry wines were observed. The post-fermentation addition caused a significant loss of red color in the wines. This fact was related with the drastic decrease of anthocyanin concentration. On the other hand, no changes were observed in the concentration of vitamin C, total tannins and antioxidant activity.