How to improve the mouthfeel of wines obtained by excessive tannin extraction

Abstract

AIM: Red wines felt as astringent and bitter generally show high content of tannins due to grape phenolic compounds’ extraction in the maceration process.  Among different enological practices, mannoproteins have been shown to improve the mouthfeel of red wines (1) and the color (2,3). In this work, we evaluated the effect of mannoproteins on the mouthfeel profile of Sangiovese wines obtained by excessive tannin extraction.

METHODS: Extended maceration (E), marc press (P), and free-run (F) wines were aged three and six months in contact with three different mannoproteins (MP, MS, MF) at 20 g/hL. Phenolic analyses comprised: total anthocyanins, low and high molecular weight proanthocyanidins. The color was studied by color parameters, CIELab coordinates, and pigmented polymers. The wines’ sensory characteristics: astringency subqualities (silk, velvet, dry, corduroy, adhesive, aggressive, hard, soft, mouth-coat, rich, full-body, green, grainy, satin, pucker, persistent), taste, aroma, and odor, were evaluated.

RESULTS: Pigmented polymer formation was differently promoted in all wines. Multi Factorial Analysis revealed significant correlations between subqualities, color parameters, and phenolic compounds for each wine. Some mouthfeel attributes seem to depend on the equilibrium between anthocyanins and pigmented polymers and then on anthocyanins and proanthocyanidins ratio. CONCLUSIONS: Mannoproteins showed a different effect on mouthfeel depending on the wine. The choice of treatment for extended maceration, free-run, and marc press wines can also be made considering results on color stability. The aging on mannoproteins can represent a way to improve the mouthfeel of wines highly rich in tannins.