Reducing the negative sensory impact of volatile phenols in red wine with different chitosans: Effect of structure on efficiency

- Chitosan is effective in reducing the sensory perception of the Brett-character.
- Chitosan efficiency seems to dependent on the deacetylation degree.
- Decreased headspace volatile phenols abundance increased fruity and floral attributes.
- Chitosan addition at low doses didn't change wine colour and phenolic composition.
- Crustacean chitosans were more efficient than fungal chitosan.

“Brett character” is a negative sensory attribute acquired by red wines when contaminating Dekkera/Brettanomyces yeasts produce 4-ethylphenol and 4-ethylguaiacol, known as volatile phenols (VPs), from cinnamic acid precursors. In this study, chitins and chitosans with different structural features, namely deacetylation degree (5-91%) and molecular weight (24-466 kDa) were used for the reduction of this sensory defect. Chitins and chitosans decreased 7-26% of the headspace abundance of VPs without changing their amounts in wines. The efficiency of reduction increased with the deacetylation degree and applied dose. Reduction of headspace abundance of VPs by chitosans enabled significant decreases in the negative phenolic and bitterness attributes and increased positive fruity and floral attributes. Results show that chitosan with high deacetylation degrees, including fungal chitosan, which is already approved for use in wines, is an efficient approach for reducing the negative sensory impact of VPs in red wines.