Volatile and phenolic profile in Pedro Ximénez sweet wines and mistelas under oxidative conditions

In the present work, the content of volatile and phenolic compounds in sweet wines and mistelas made from sun-dried Pedro Ximénez grapes, with and without skins during alcoholic fermentation, has been studied during their storage under oxidative conditions. Three possible significant factors have been considered: oxidative storage time, type of elaboration, and presence or absence of grape skins during alcoholic fermentation.

The presence or absence of skins during alcoholic fermentation showed a low influence on the content of low molecular weight phenolic compounds and furfurals during the oxidative storage in stainless steel tanks. Storage time together with type of elaboration turned out to be the most influential factors, with decreases in phenolic compounds due to possible oxidative phenomena and increases in furfurals. The evolution of phenolic compounds during oxidative aging showed to be dependent on type of elaboration, with significant decreases at the beginning of storage for mistelas. In the case of volatile compounds, a high number of them showed significant differences in relation to the type of elaboration. The presence or absence of grape skins was, mainly, significant for ethyl esters, acids and alcohols, with higher relative extent in the absence of grape skins. For these compounds, the type of elaboration-aging time interaction was also the most significant type, with significant decreases during the first 3 months of aging in mistelas.

During the oxidative aging in stainless steel tanks, of sweet wines and mistelas elaborated with and without contact of grape skins during alcoholic fermentation, the main factor was oxidative aging time for phenolic and furanic compounds. Although, for volatile compounds, it was the type of elaboration, with mistelas showing a very different behavior to that of naturally sweet wines and natural sweet wines. © 2025 Society of Chemical Industry.