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

AWRI: Identification Of The Major Drivers Of ‘Phenolic’ Taste In White Wines
produce irritation exist. Oleocanthal is one such compound. It is responsible for the peppery, back of
the throat burning sensation that typifies extra virgin olive oil. Recently, oleocanthal receptors located
in the human pharynx have been identifed (Peyrot des Gachons et al. 2011).
The ‘burning aftertaste’ perceived by the assessors was negatively associated with both in-mouth
hotness (r= -0.331) and hot aftertaste (r= -0.395), suggesting that ‘burning aftertaste’ represents a
sensory character that is not totally related to alcohol content. However, the model wine (that
contained alcohol but not phenolics) was rated as having a burning aftertaste, suggesting that alcohol
induced hot aftertaste and a similarly perceived phenolic induced character were not totally
differentiated by the tasters.
Adding caftaric acid to the model wine suppressed the perception of burning aftertaste, while adding
GRP tended to increase burning sensation. This suggests that GRP produces a burning sensation in its
own right, while the presence of caftaric acid interferes with the burning aftertaste induced by alcohol.
Therefore two mechanisms are likely to be in play.
GRP was found to have an enhancing effect on ‘oily mouth-feel’ (Figure 7-7, p=0.096). The
relationship between perceived viscosity and oiliness is less clear as they were moderately correlated
(r= 0.53, p=0.141). However, by keeping both ‘oily mouth-feel’ and ‘viscosity’ in their list of relevant
attributes, they were seen as distinct characters worthy of inclusion by the tasting panel.
What is new here is the notion that small molecular weight phenolics from white wines may suppress
astringent and ‘burning aftertaste’ sensations arising from acidity or alcohol rather than causing them
as has previously been presumed. The mechanisms underlying this are unclear but warrant further
investigation. While there is evidence that GRP contributes to a burning aftertaste, in general, GRP
and caftaric acid when tasted at wine like concentrations have either no effect or a suppressive effect
on ‘phenolic tastes’ in white wine.
61
Astringency
3.0
2.5
2.0
1.5
1.0
0.5
0.0
b
a
b
Caftaric Acid GRP
b
a a
60 mg/L
30 mg/L
0 mg/L
Figure 7-3: Mean ‘astringency’ intensity. Means with different subscripts are significantly
different (p