Impact of fungicides mepanipyrim and tetraconazole on phenolic profile and colour of Mencía red wines

Abstract The influence of mepanipyrim (Mep) and tetraconazole (Tetra) and their formulations (Mep-Form and Tetra-Form) on the chromatic characteristics of Mencia wines was evaluated. Fungicides were applied at concentrations corresponding to their Maximum Residue Levels (MRL) on grapes and at 2MRL. The decay rate of both fungicides during winemaking process confirmed the high dissipation percentage (>85%). To evaluate possible modifications in phenolic composition and colour, control wines were also analysed. No effects on anthocyanins for Mep, Mep-Form and Tetra (MRL) treatments were observed. Only a decrease of these pigments was registered when Tetra (2MRL: 43%) and Tetra-Form (MRL: 75% and 2MRL: 64%) were applied. Besides, the addition of Mep, Mep-Form and Tetra to the must did not decrease the content of flavonols, flavan-3-ols and non-flavonoids; meanwhile the addition of Tetra-Form reduced these phenolic compounds (around 35%, 52% and 17%, respectively).