Search Results (4)

Viticulture is increasingly seeking sustainable practices that enhance grape quality while reducing reliance on synthetic inputs. Among bio-based strategies, biochar has attracted growing interest for its potential to improve soil fertility and influence plant metabolism. However, its effects can vary depending on formulation and application methods. This study evaluated the effects of the use of solid (SB) and liquid biochar (LB) on the biochemical and nutritional composition in leaves, berry skins, and must of a grapevine (Vitis vinifera L., cv. Sangiovese) cultivated in a vineyard in Tuscany (Italy). SB was applied once to the soil at 2.5% (w/w), while LB was applied five times/season at 10% (v/v) via fertigation. Results revealed formulation-specific effects on grapevine physiology and fruit composition. SB maintained leaf chlorophyll concentrations, increased total soluble proteins (+65%), total polyphenols (+57%), and tannin content (+33%) in berry skins and must, and reduced Cu and Zn. Conversely, LB reduced leaf chlorophyll concentrations (−24%) and nutrient contents (P, Fe, Cu, and Zn), but increased total flavonoids (+13%), antioxidant capacity (+20%), and vitamin C (+18%) in berry skins, alongside higher fructose and reducing sugars in musts. The findings highlight biochar’s potential as a bio-based input in viticulture, emphasizing the importance of formulation and application strategy. SB appears suited to long-term soil improvement and enhanced phenolic richness, while LB may modulate sugar metabolism for targeted enological outcomes. Full article

This study evaluates the impact of grape variety and harvesting method—manual versus mechanized—on must composition, wine quality, and economic performance in the Târnave viticultural area of Romania. Four grape varieties—Pinot Noir, Sauvignon Blanc, Fetească Regală, and Muscat Ottonel—were analyzed. Manual harvesting increased reducing sugars by 4.3–5.1 g/L and decreased titratable acidity by 0.6–0.8 g/L, particularly in Pinot Noir and Muscat Ottonel. Alcohol content was higher by 0.4–0.6 vol% in manually harvested samples, and dry extract increased by 1.0–1.3 g/L. Mechanized harvesting raised catechin concentrations by 15–19 mg/L due to enhanced skin maceration, but also slightly elevated volatile acidity (by ~0.1 g/L). From an economic perspective, labor cost was reduced from 480 lei/ton (approx. EUR 96) for manual harvesting to 120 lei/ton (approx. EUR 24) with mechanization. Fuel and maintenance costs for mechanized equipment averaged 85 lei/ha (EUR 17), and equipment depreciation was estimated at 100 lei/ton (EUR 20). The total harvesting cost per ton decreased from 480–520 lei to 300–320 lei (approx. EUR 96 to EUR 64), representing a ~38% reduction. The study supports a hybrid approach: manual harvesting for sensitive or premium cultivars, and mechanization for cost-efficient, large-scale production, aligning wine quality goals with economic sustainability. Full article

The disruptive effect exerted by high-power ultrasound (US) on grape cell walls is established as the reason behind the chromatic, aromatic and mouthfeel improvement that this treatment causes in red wines. Given the biochemical differences that exist between the cell walls of different grape varieties, this paper investigates whether the effect of the application of US in a winery may vary according to the grape variety treated. Wines were elaborated with Monastrell, Syrah and Cabernet Sauvignon grapes, applying a sonication treatment to the crushed grapes using industrial-scale equipment. The results showed a clear varietal effect. The wines made with sonicated Syrah and Cabernet Sauvignon grapes showed an important increase in the values of color intensity and concentration of phenolic compounds, and these increases were higher than those observed when sonication was applied to Monastrell crushed grapes, whereas Monastrell wines presented the highest concentration in different families of polysaccharides. These findings correlate with the differences in the composition and structure of their cell walls since those of Monastrell grapes presented biochemical characteristics associated with a greater rigidity and firmness of the structures. Full article

The enology industry in North Dakota is extremely young, with less than twenty years of existence. At times throughout the development of the North Dakota viticulture and enology industries, commercial wine producers have elected to purchase or store fresh harvested grapes as frozen musts. To investigate the fermentation outcomes related to skin contact for red grapevine musts, a postfreeze fermentation experiment was conducted with fruit from ‘Frontenac’, one of the most widely grown red grapevines in the Upper Midwest U.S. and North Dakota. Four fermentation treatments were applied to frozen ‘Frontenac’ grapevine musts: steam juice extraction, rosé, 1 day after inoculation (DAI) skin contact, and 9 DAI skin contact. Samples were collected daily for ten days and analyzed for fermentation progress and spectrophotometric monitoring of wine color attributes and total phenolics. The final wines were analyzed two years after bottling. Steam-extracted musts were initially darkest; however, they were lighter as final wines than the 9 DAI wines and similar to rosé wines in lightness. Total phenolics were greatest for 9 DAI wines and total red pigments were lowest for steam-extracted wines. While differences between treatments were detected, the wines remained visually similar; this indicates that color extraction within the freeze–thaw processes of musts may obliterate subtly and make it difficult to produce wines of light color when stored under these conditions. Continued work with additional grapevines beyond ‘Frontenac’ may help fine-tune must and fermentation extraction procedures for small-scale wineries growing cold-hardy grapevines. Full article