Interactive effect of pre-fermentative grape freezing and malolactic fermentation on the anthocyanins profile in red wines prone to colour instability
Aakriti Darnal, Simone Poggesi, Adriana Teresa Ceci, Tanja Mimmo, Emanuele Boselli, Edoardo Longo
Abstract
Abstract The effects of pre-fermentative freezing of red grapes from Schiava variety and co-inoculation with lactic bacteria were evaluated on the profile of anthocyans of the musts and the finished wine. Peonidin-3-glucoside is the main anthocyanin in Schiava grape musts, but it was overcome by malvidin-3-glucoside at bottling. Grape freezing increased the extraction of all anthocyanins in the musts. However, the amount of all anthocyanins except peonidin-3-glucoside and malvidin-3-glucoside was lower in wines from frozen grapes than in control wines. Wines obtained with co-inoculation showed higher anthocyanin content than their respective controls. Petunidin-3-(6′′- p- coumaroyl)-glucoside, peonidin-3-(6′′ -cis - p- coumaroyl)-glucoside and malvidin-3-(6′′- trans - p- coumaroyl)-glucoside were dramatically affected by the interaction of the two applied factors. Colorimetric hue (H*) was strongly correlated with peonidin-3-glucoside, and spectrophotometric tint (N) with malvidin-3-glucoside. Tint also showed a positive correlation with malolactic fermentation. Graphical abstract