Main content area

Pomace limits tannin retention in Frontenac wines

Nicolle, Paméla, Marcotte, Charlène, Angers, Paul, Pedneault, Karine
Food chemistry 2019 v.277 pp. 438-447
alcoholic fermentation, bentonite, flavanols, heat, maceration, pomace, proteins, tannins, wines
The impact of different factors (must protein treatment: bentonite and heat; pomace: fermented with and without; tannin addition: 0–9 g/L; and time of maceration: 0–11 days) on tannin, pigment, and protein extraction/retention in Frontenac wines was investigated. Wine tannin concentration and composition were determined by HPLC-fluorescence. Protein and pigment parameters were analysed by BCA assay and Boulton’s method, respectively, using UV-spectrophotometry. Results: Bentonite and heat significantly reduced wine protein concentration at the end of alcoholic fermentation but heat was less efficient than bentonite (1.8–5.0 times less). Removing wine proteins did not improve tannin retention in wines (p > 0.1032) but fermenting without pomace significantly improved their retention (up to 2.4 times), especially that of polymeric flavan-3-ols (up to 27.8%). An addition of 3 g/L of enological tannins in wines, fermented with or without pomace, was necessary to increase wine tannin concentration significantly.