Hydroxycinnamates of Vitis vinifera: Sensory assessment in relation to bitterness in white wines

The bitter and astringent taste properties of hydroxycinnamoyl tartaric acids have been responsible for incorrect speculation that these compounds influence the taste of wine. The sensory contribution of the major hydroxycinnamates found in wine was evaluated by duo—trio difference tests in model wine solutions and in white wine. The major hydroxycinnamate compound, trans-caffeoyl tartaric acid, was not detectable when added at the highest level at which it has been found in wine, 150 mg litre−1. Similarly, no significant difference in taste was produced when caffeic acid and p-coumaric acid were added at 120 mg litre−1 and 30 mg litre−1, respectively. Trans-2-S-glutathionyl caffeoyl tartaric acid, a product of oxidase activity in must, was not detectable at 50 mg litre−1. It was concluded that the hydroxycinnamates do not play any direct role in the taste of wines.