Identification of the major drivers of 'phenolic' taste in ... - GWRDC

AWRI: Identification Of The Major Drivers Of ‘Phenolic’ Taste In White Wines
Correlation coefficient (r)
92
1.0
0.8
0.6
0.4
0.2
0.0
-0.2
-0.4
-0.6
-0.8
-1.0
Figure 8-22: Correlation coefficients between concentration of phenolic compound classes and
sensory attributes. All 2010 wines. * indicates sensory attribute was adjusted for pH effect
Good associations were seen between bitter and bitter aftertaste character and A280 in 2010 (Table 8-5).
The concentrations of many of the phenolic groups were associated with bitter aftertaste (Figure 8-22).
PLS regression analysis showed that a significant contributor to the relationship were the flavan-3-ols,
benzoic acids and to a lesser extent GRP and the cinnamic acids. Flavan-3-ols were found to be abundant
in one of the few bitter fractions extracted from commercial wines (Chapter 6), and have been reported to
be important bitter compounds in tea (Narukawa et al. 2010). Adding GRP and caftaric acid to model
wine did not result in a consistent increase in bitterness (Chapter 7). PLS analysis suggested that GRP and
caftaric acid have some influence on bitterness. However, it is reasonable to assume that the direct
approach of assessing these compounds in isolation will be more robust than using correlative methods
such as PLS.
Astringency* Viscosity* Hotness Acidity Bitter AT Acid AT
Benzoic acids Benzoic acid glycosides
Benzoic acid ethyl esters GRP's
Cinnamic acids Cinnamic acid glycosides
Cinnamic acid ethyl esters Phenols
Total peak area measured at 280 nm has been used as a proxy for total phenolics and was correlated
against sensory ratings given to the 2010 wines (Figure 8-24). Astringency (adjusted for pH effect),
hotness and acidity were negatively correlated with peak area, while viscosity (adjusted for pH effect) and
bitter aftertastes were positively correlated with peak area.