Browsing by Author "Merkytė V"

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    Effects of Long-Term Bottle Storage on Red and Rosé Wines Sealed with Different Types of Closures
    (MDPI (Basel, Switzerland), 2021-12) Tchouakeu Betnga PF; Longo E; Merkytė V; Dupas de Matos A; Rossetti F; Boselli E; Câmara JS; Teixeira JAC; Perestrelo RM
    Volatile and non-volatile chemical profiles, free and total SO2 and dissolved oxygen content were studied in three red (Merlot, Lagrein red, St. Magdalener) and one rosé (Lagrein rosé) wine after 30 months of storage in bottles. Each wine was sealed with closures made of a 'blend' (B) of natural cork microgranules and polymers without glue and was compared with wines closed with other types of corks (C; a technical cork 1 + 1, or an agglomerated natural cork or a natural one-piece cork). Glutathionyl caftaric acid (GRP) was inversely correlated with total SO2 content and was higher in all three red wines closed with B compared to C, whereas epicatechin was higher in three wines closed with C compared to B. Three volatile compounds formed by fermentation (ethyl butanoate, isoamyl lactate, and octanol) were inversely correlated with both free and total SO2. In terms of their volatile profiles, ethyl octanoate and 2,3-butanediol were significantly higher in the Lagrein red wines closed with C closures, whereas no significant difference was observed in Merlot, Lagrein rosé and St. Magdalener wines. Small differences in some phenolic compounds due to the type of closure were found: GRP, syringic acid, (+)-catechin, and (-)-epicatechin differentiated the Merlot wines closed with B from the C closures. Protocatechuic acid and GRP levels differentiated the Lagrein red wines according to their closure type, whereas only (-)-epicatechin differentiated the Lagrein rosé wines. GRP, caffeic acid, (-)-epicatechin, and anthocyanin content differentiated the St. Magdalener wines according to their closure type. Even though St. Magdalener and Lagrein rosé closed with C could be distinguished from those closed with B by using the (sensory) triangle test (α = 0.05), these differences appeared to be relative as it did not include all the wines in a systematic manner.
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    Effects of Microvibrations and Their Damping on the Evolution of Pinot Noir Wine during Bottle Storage
    (MDPI (Basel, Switzerland), 8/09/2022) Poggesi S; Merkytė V; Longo E; Boselli E
    Environmental conditions such as vibrations, temperature, and exposure to light can lower the quality of bottled wine, causing great economic and image losses for wineries. Even under optimal storage conditions, environmental microvibrations can be a constant source of energy transfer to the stored bottles, and little is known about their effects over time. In this study, the effects of microvibrations on a fine Pinot noir wine were evaluated over a storage period of one year under controlled conditions and compared with those obtained using natural magnetic levitation as a damping technique to reduce the power transmitted by the vibrations. The wines were subjected to the treatments according to the following experimental set-up: (A) wines not exposed to microvibrations, but to natural magnetic levitation; (B) wines placed on a shelf in contact with the floor, and exposed to microvibrations; (C) controls, a shelf in direct contact with the floor, without the application of microvibrations; (D) wines on a shelf with natural magnetic levitation and exposed to microvibrations. Phenolic and volatile compounds were not significantly different between treatments, which is in line with the reduced energy stress applied. In contrast, the storage time significantly influenced these chemical profiles. Through the sensory analysis performed after 0 and 12 months of storage, it was possible to distinguish the wines, as the overall quality improved, especially for the microvibration-treated samples. After 12 months of storage: (a) the overall sensory quality improved for all wines compared to the samples at T0; (b) the damping of microvibrations reduced the rate of wine evolution; (c) treatment with microvibration up to 6 months was useful for improving the quality of wine not yet ready for the market. Therefore, modulation of wine evolution can be achieved by applying a combination of microvibrations and their damping, depending on the enological objective.
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    South-Tyrolean pinot blanc identity: Exploration of chemical and sensory profile changes ascribed to vineyard locations and winemaking variables.
    (Elsevier B.V., 2024-09-16) Darnal A; Poggesi S; Merkytė V; Longo E; Boselli E
    The sensory and chemical properties of 'Pinot Blanc' wine from South Tyrol were studied in relation to vineyard location and winemaking technique. Musts and wines were collected from a local producer. Wines made with the same control vinification but from different vineyards (Aldino 800, Montagna 450, and Klaus 550 m.a.s.l) were analyzed. Then wines from grapes of the same vineyard but made with different vinifications (grape freezing and co-inoculation of yeast with malolactic bacteria, both compared against controls) were compared. The highest-altitude vineyard (cooler temperatures, increased UV radiation, and increased airflow) impacted positively the wine quality. The different vinifications produced differences at various storage times. Finally, sensory attributes predictors for the overall quality and related chemical variables were identified. As climate change pushes growers to increasingly high-altitude viticulture, if/when allowed by the environmental conditions, these results can contribute to understand which winemaking techniques are best in these more challenging conditions.