UMR AGAP Equipe Diversité, adaptation et amélioration de la vigne (DAAV)Background and Aims: Based on 19 nuclear simple sequence repeat markers and parental analysis, we aimed to identify and propose the pedigree of different accessions held at the Estación Experimental Agropecuaria Mendoza of the Instituto Nacional de Tecnología Agropecuaria germplasmcollection. The results were compared with data recorded in large, international databases.Methods and Results: We identified 37 different cultivars, of which 18 were original and not previously identified. The parentage analysis showed that European cultivars, such as Muscat of Alexandria, Muscat à Petits Grains, Listán Prieto, Mollar Cano and Malbec, were involved in natural crossings resulting in different South American cultivars.Conclusions: Many of the cultivars identified here represent unique individuals based on their genotype. The number of cultivars that participated as progenitors in the origin of South American germplasm is higher than previously thought.Significance of the Study: Germplasm collections planted many years ago play a key role in the conservation and characterisation of genotypes that otherwise may have been lost. It is highly probable that there might be other genotypes not identified and mixed in old vineyards. The identification, rescue and conservation of these genotypes are a challenge to preserve the existing genetic variability

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Merlot grapes were harvested with three maturity levels (21.1, 23.1, and 25.1 Brix), and processed with or without the application of microwave-assisted extraction (MW). The detailed phenolic composition and color were followed during winemaking. The MW treatment did not affect the basic chemical composition of the wines. Upon crushing, MW caused a 211% improvement in anthocyanins in the wines of the first harvest and an 89% improvement in the wines of the third harvest. At bottling, MW favored the formation of pyranoanthocyanins and tannin-anthocyanin dimers. Tannin extraction was not affected by MW just after application of this process, but improvements of 30, 20, and 10% on MW-treated wines of the first, second, and third harvest, respectively, were recorded at pressing. The formation of polymeric pigments during aging generally increased along with harvest date and was only favored in MW-treated wines of the first and third harvest, with preferential formation of small polymeric pigments, in accordance with enhanced anthocyanin extraction in these wines. Initial improvements of wine color upon application of MW in the wines of the first, second, and third harvest were of 275, 300, and 175%, respectively. Although these differences subsided or disappeared for the wines of the second and third harvest during aging, the wines of the first harvest treated with MW retained 52% more color than Control wines at day 150 post-crushing. Results suggest the MW treatment was more efficient in extracting and retaining phenolics and color when applied to unripe fruit.Fermentation 2019, 5, 15 2 of 16 varieties), and tannins (located both in skins and seeds) change during ripening, winemakers usually define harvest decisions based on a complex combination of factors that include weather forecast and disease pressure, fruit basic chemistry (including Brix, pH, and titratable acidity), and phenolic composition (including anthocyanins and tannins).Studies in Cabernet Sauvignon, Merlot, and Tempranillo have found a direct link between grape maturity, usually defined in terms of color and phenolic composition, and wine composition [1,3,8]. This accumulated knowledge has, in turn, allowed the production of wines with specific sensory features based on harvest time. Bindon et al. (2014) [9] studied the effect of five different harvest dates, with sugar levels spanning from 20 to 26 Brix, and corresponding alcohol contents in the finished wines spanning from 12 to 15.5% v/v. It was found that wine anthocyanins and tannins increased with harvest date, as well as an enhanced extraction of skin-derived phenolics [9]. From a sensory standpoint, later harvest dates produced wines with less green or vegetative attributes and more dark fruit attributes [1].Because grape maturity plays such a critical role in wine composition, it is expected that the outcomes of a given winemaking technique may be different based on when the fruit is harvested. In turn, variations in ethanol due to changes in fruit maturity may have an effect in phenolic e...

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The growing demand in recent years for sustainable wine production has led to the management of waste and by-products. Among them, vine-shoots could be used as additives comparable to the oak fragments widely employed in enology. This work analyzes the feasibility of applying vine-shoot chips during winemaking and the aging of Malbec and Bonarda wines from Mendoza (Argentina) and evaluates their chemical and sensory impact. Toasted (CHT) and untoasted (CHWT) vine-shoot chips obtained from a Bonarda vineyard were added in Malbec and Bonarda grapes during winemaking (Experiment A): C, control; CHWT, 12 g/L; CHT, 12 g/L. Furthermore, the same treatments were applied during aging (1M, 30 days; 2M, 60 days; 4M, 120 days) to the finished wines under controlled conditions (Experiment B). The impact of vine-shoot chips during winemaking was different between varieties. For Malbec alone, CHT caused a significant decrease in tannins, anthocyanins, and polymeric pigments, and a modification of wine color. During aging, CHWT and CHT had an impact mainly at the sensory level, increasing the wine’s complexity in terms of aromatic attributes and mouthfeel. In conclusion, the proposed technology could be a simple and economical tool for red wine production of high chemical and organoleptic quality.

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Summary Two alternatives of cold soak (CS), traditional external refrigeration (CS‐T) and use of solid CO2 (CS‐DI), were evaluated in Malbec wines and contrasted against a control (C) during winemaking and up to 24 months of bottle ageing. Sugar consumption up to 5 g L day‐1 was observed in CS‐T during the CS period. Both the viability of the population of Saccharomyces and non‐Saccharomyces were maintained during CS. CS‐T was detrimental for the anthocyanin and phenolic content and caused a reduction of absorbance in the visible spectrum of the wines relative to C and CS‐DI. CS‐DI had an early positive effect in the anthocyanin content and chromatic properties, but this effect subsided after 6 months of bottle ageing relative to C. From a sensory standpoint, CS‐T had the lowest colour saturation and a marked acetaldehyde character. CS‐DI wines were the most saturated in colour at press and early ageing, whereas a balsamic‐like aroma developed during bottle ageing. C wines were characterised by red fruits aroma, reduction and astringency early during winemaking, but a decrease in astringency and the reduction character occurred during bottle ageing.

Background and Aims: These last years, minor cultivars have gained attention as they provide an opportunity to offer original products in a global market and to combat global warming. Recent evidence brought to light the existing diversity within the group of autochthonous cultivars from Argentina and other South American countries, commonly known as criollas. The objective was to prospect, rescue and identify grapevine phenotypes recovered in ancient vineyards as putative criollas, in the western provinces of Argentina. Methods and Results: We collected 60 samples in 11 locations. Their identity and pedigree were analysed through nuclear simple sequence repeat (nSSR) markers. The 60 samples were grouped in 45 different genotypes, 19 of them corresponding to previously registered cultivars, while 26 were new genotypes, with no correspondence in international databases. The majority (18) of the 26 new genotypes were related with the criollas group while other genotypes presented a totally different genetic profile and its origin remains to be elucidated. Conclusions: The diversity within the South American cultivars is higher than previously thought. Ancient vineyards, located in isolated valleys, are reservoirs of minor cultivars, and growers have played a key role in maintaining and conserving them. Significance of the Study: This genetic diversity constitutes a valuable tool to explore alternatives for diversification and adaptation to climate change.