Acidity reduction in northern region berry juices by the malolactic bacterium Oenococcus oeni

Acidity of juices from northern berries was reduced by inoculating with a malolactic microorganism, Oenococcus oeni. The berries were white and black currant, bilberry, lingonberry, and, for comparison, an apple cultivar. Malic acid was first converted to lactic acid in all fermentations, while soluble sugars and citric acid remained unattacked. Upon exhaustion of malic acid, sugar and citric acid degradations were initiated simultaneously. Sequential utilization of substrates by O. oeni offers a basis for multitude compositional changes in acidic juices. Elimination of malic acid alone led to a noticeable reduction of acidic taste in these berry juices.