# Discrimination of Smoke-Exposed Pinot Noir Wines by Volatile Phenols and Volatile Phenol-Glycosides

## TL;DR

This study identifies volatile phenols and their glycosides as potential markers to distinguish smoke-exposed Pinot noir wines from non-exposed ones.

## Contribution

The study introduces VP-glycosides as novel indicators for detecting smoke taint in wines.

## Key findings

- Smoke-exposed wines had significantly higher levels of VP-glycosides compared to non-exposed wines.
- VP-glycosides showed strong positive correlations with each other and with free and acid-hydrolyzed VPs.
- Multivariate analysis successfully differentiated smoke-exposed from non-smoke-exposed wines.

## Abstract

This study investigated the correlation between five primary volatile phenols (VPs) and their glycosides in smoke-exposed and non-smoke-exposed Pinot noir wines to assess and identify potential markers for smoke taint. The results showed that all putative VP-glycosides in smoke-exposed wines were higher than in non-smoke-exposed wines, with a fold change ranging from 2.11 to 31.88 for the top fifteen differentiations. VP-glycosides showed strong positive correlations among themselves, with correlation coefficients of 0.94 for hexose-guaiacol vs. pentose (P)-hexose (H)-cresol and 0.92 for syringyl-β-D-glucopyranoside vs. H-P-4-methylguaiacol. VP-glycosides also showed relatively high correlations with free and strong acid-hydrolyzed VPs. The correlation coefficient between H-P-guaiacol and free-form guaiacol is 0.71, and between H-P-guaiacol and total guaiacol is 0.78. The strong correlation suggests that these compounds are interconnected and regulated by the severity of smoke exposure. Multivariate analysis effectively differentiated smoke-exposed wines from non-smoke-exposed ones. However, more research is needed to fill the gaps in understanding smoke-derived compounds.