Malolactic fermentation in white wines

Previous studies have proven the potential of antimicrobial plant extracts to delay malolactic fermentation (MLF) in red wines. With the final end of extending their applicability in oenology, the aim of this study was to investigate whether the addition of antimicrobial extracts (from eucalyptus leaves and almond skins) to white wines (i.e., Chardonnay wine), as a way to control MLF, would affect wine organoleptic properties, in particular those related to their volatile and phenolic composition. Although addition of both extracts led to statistically significant changes (p<0.05) in the concentration of several volatile and phenolic compounds, only few of them showed contents higher than their sensory thresholds, meaning that the changes observed in their concentration could slightly affect the final wine aroma and astringency. However, use of the extracts in the elaboration of white wines needs to be assessed in future experiments at winery scale, including wine sensorial analysis.

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Mature white wines from grapes of Serbian breeding under the conditions of Russia

Scientific Works of North Caucasian Federal Scientific Center of Horticulture Viticulture Wine-making ◽

10.30679/2587-9847-2018-15-122-126 ◽

2018 ◽

Vol 15 ◽

pp. 122-126

Author(s):

A.V. Dergunov ◽

Keyword(s):

White Wines

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Effects of co-fermentation and sequential malolactic fermentation on antioxidant activities and phenolic components of red-fleshed apple cider

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/705/1/012008 ◽

2021 ◽

Vol 705 (1) ◽

pp. 012008

Author(s):

Cui-Xia Li ◽

Xian-Hua Zhao ◽

Xue-Sen Chen

Keyword(s):

Antioxidant Activities ◽

Malolactic Fermentation ◽

Apple Cider ◽

Phenolic Components

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Effect of Pre-Fermentative Maceration and Fining Agents on Protein Stability, Macromolecular, and Phenolic Composition of Albariño White Wines: Comparative Efficiency of Chitosan, k-Carrageenan and Bentonite as Heat Stabilisers

Foods ◽

10.3390/foods10030608 ◽

2021 ◽

Vol 10 (3) ◽

pp. 608

Author(s):

Inma Arenas ◽

Miguel Ribeiro ◽

Luís Filipe-Ribeiro ◽

Rafael Vilamarim ◽

Elisa Costa ◽

...

Keyword(s):

Phenolic Compounds ◽

Protein Stability ◽

White Wine ◽

The Other ◽

White Wines ◽

Comparative Efficiency ◽

Fining Agents ◽

Protein Instability ◽

Related Proteins ◽

Protein Stabilisation

In this work, the effect of pre-fermentative skin maceration (PFSM) on the chemical composition of the macromolecular fraction, polysaccharides and proteins, phenolic compounds, chromatic characteristics, and protein stability of Albariño monovarietal white wines was studied. PFSM increased the extraction of phenolic compounds and polysaccharides and reduced the extraction of pathogenesis-related proteins (PRPs). PFSM wine showed significantly higher protein instability. Sodium and calcium bentonites were used for protein stabilisation of wines obtained with PFSM (+PFSM) and without PFSM (−PFSM), and their efficiencies compared to fungal chitosan (FCH) and k-carrageenan. k-Carrageenan reduced the content of PRPs and the protein instability in both wines, and it was more efficient than sodium and calcium bentonites. FCH was unable to heat stabilise both wines, and PRPs levels remained unaltered. On the other hand, FCH decreased the levels of wine polysaccharides by 60%. Sodium and calcium bentonite also decreased the levels of wine polysaccharides although to a lower extent (16% to 59%). k-Carrageenan did not affect the wine polysaccharide levels. Overall, k-carrageenan is suitable for white wine protein stabilisation, having a more desirable impact on the wine macromolecular fraction than the other fining agents, reducing the levels of the wine PRPs without impacting polysaccharide composition.

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Evaluation of the Storage Conditions and Type of Cork Stopper on the Quality of Bottled White Wines

Molecules ◽

10.3390/molecules26010232 ◽

2021 ◽

Vol 26 (1) ◽

pp. 232

Author(s):

María Consuelo Díaz-Maroto ◽

Manuel López Viñas ◽

Lourdes Marchante ◽

María Elena Alañón ◽

Ignacio Javier Díaz-Maroto ◽

...

Keyword(s):

Volatile Compounds ◽

Light Exposure ◽

Total Content ◽

Storage Conditions ◽

Sensory Profile ◽

Cork Stopper ◽

White Wines ◽

White Leds ◽

Retail Outlets

The effects of different storage conditions, light exposure, temperature and different commercially available cork stoppers on the phenolic, volatile and sensorial profile of Verdejo wines were studied. Two natural corks of different visual quality and a microgranulated cork stopper were investigated over one year at two different storage conditions. One simulating light exposure and temperature in retail outlets and the other simulating optimal cellar conditions (darkness and 12 °C). The wines stored under commercial conditions showed greater losses of total and free SO2 and higher levels of brown-yellowish tones, related to the oxidation of flavan-3-ols. Although these wines underwent a decrease in the total content of stilbenes, a significant increase in trans-piceid was observed. In addition, these wines suffered important changes in their volatile and sensory profile. Volatile compounds with fruity and floral aromas decreased significantly, while volatile compounds related to aged-type characters, as linalool oxides, vitispirane, TDN or furan derivatives increased. Wines stored in darkness at 12 °C underwent minor changes and their sensory profiles were similar to wine before bottling. The high-quality natural corks and microgranulated corks better preserved the quality of the white wines from a sensory point of view. These results showed that temperature and light exposure conditions (diffuse white LEDs and 24 ± 2 °C) in retail outlets considerably decrease the quality of bottled white wines and, consequently, their shelf life, due to the premature development of aged-type characters.

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Use of Yeast Mannoproteins by Oenococcus oeni during Malolactic Fermentation under Different Oenological Conditions

Foods ◽

10.3390/foods10071540 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1540

Author(s):

Aitor Balmaseda ◽

Laura Aniballi ◽

Nicolas Rozès ◽

Albert Bordons ◽

Cristina Reguant

Keyword(s):

Energy Source ◽

Nutrient Medium ◽

Alcoholic Fermentation ◽

Hydrolytic Activity ◽

Malolactic Fermentation ◽

Oenococcus Oeni ◽

Consumption Patterns ◽

Inhibitor Compounds

Oenococcus oeni is the main agent of malolactic fermentation in wine. This fermentation takes place after alcoholic fermentation, in a low nutrient medium where ethanol and other inhibitor compounds are present. In addition, some yeast-derived compounds such as mannoproteins can be stimulatory for O. oeni. The mannoprotein concentration in wine depends on the fermenting yeasts, and non-Saccharomyces in particular can increase it. As a result of the hydrolytic activity of O. oeni, these macromolecules can be degraded, and the released mannose can be taken up and used as an energy source by the bacterium. Here we look at mannoprotein consumption and the expression of four O. oeni genes related to mannose uptake (manA, manB, ptsI, and ptsH) in a wine-like medium supplemented with mannoproteins and in natural wines fermented with different yeasts. We observe a general gene upregulation in response to wine-like conditions and different consumption patterns in the studied media. O. oeni was able to consume mannoproteins in all the wines. This consumption was notably higher in natural wines, especially in T. delbrueckii and S. cerevisiae 3D wines, which presented the highest mannoprotein levels. Regardless of the general upregulation, it seems that mannoprotein degradation is more closely related to the fermenting medium.

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Volatilome of white wines as an indicator of authenticity and adulteration control using statistical analysis

Australian Journal of Grape and Wine Research ◽

10.1111/ajgw.12486 ◽

2021 ◽

Author(s):

I.K. Karabagias ◽

V.K. Karabagias ◽

A.V. Badeka

Keyword(s):

Statistical Analysis ◽

White Wines

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Characterisation of Extracts Obtained from Unripe Grapes and Evaluation of Their Potential Protective Effects against Oxidation of Wine Colour in Comparison with Different Oenological Products

Foods ◽

10.3390/foods10071499 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1499

Author(s):

Giovanna Fia ◽

Ginevra Bucalossi ◽

Bruno Zanoni

Keyword(s):

Antioxidant Activity ◽

Red Wine ◽

Waste Product ◽

Natural Antioxidants ◽

White Wine ◽

Small Scale ◽

Protective Effects ◽

White Wines ◽

Accelerated Oxidation ◽

Wine Colour

Unripe grapes (UGs) are a waste product of vine cultivation rich in natural antioxidants. These antioxidants could be used in winemaking as alternatives to SO2. Three extracts were obtained by maceration from Viognier, Merlot and Sangiovese UGs. The composition and antioxidant activity of the UG extracts were studied in model solutions at different pH levels. The capacity of the UG extracts to protect wine colour was evaluated in accelerated oxidation tests and small-scale trials on both red and white wines during ageing in comparison with sulphur dioxide, ascorbic acid and commercial tannins. The Viognier and Merlot extracts were rich in phenolic acids while the Sangiovese extract was rich in flavonoids. The antioxidant activity of the extracts and commercial tannins was influenced by the pH. In the oxidation tests, the extracts and commercial products showed different wine colour protection capacities in function of the type of wine. During ageing, the white wine with the added Viognier UG extract showed the lowest level of colour oxidation. The colour of the red wine with the UG extract evolved similarly to wine with SO2 and commercial tannins. The obtained results indicated that natural and healthy UG extracts could be an interesting substitute for SO2 during wine ageing.

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