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Aroma is an identifying characteristic of wines and is of crucial importance for the consumer appreciation. Among all odour-active compounds, some key molecules appear only after ageing and give a strong contribution to both identity and added value of the wine bottle. Methyl salicylate (MeSA) is an odorant which usually appears after ageing and could provide an increase in fruity aromas and freshness. This odour-active ester can be found mainly bound to one or more carbohydrates, forming a glycoside. In wines, the hydrolysis of glycosides contributes to the aroma evolution of wine. In our previous works, MeSA was found in relevant content, both in bound and free form, in some genetically related Italian varieties such as Trebbiano di Lugana, Trebbiano di Soave (both employed in the production of Lugana wines), and Verdicchio. In this research, a straightforward filter-and-shot LC-MS/MS method was used for the determination of 7 different MeSA glycosides in 246 samples representative of 18 different monovarietal Italian white wines. MeSA glycosides were found in relevant concentrations in Verdicchio and Lugana wines, whereas they were determined for the first time in all others. Results were in accordance with the literature since Lugana and Verdicchio emerged for the total amount of glycosides, together with Erbaluce, whose richness was not known to date. This trend was observed for all analytes, with stronger intensity, especially in MeSA–glucoside, MeSA–gentiobioside and MeSA–violutoside. The triglycosylated form was not detected in any case. The same trend was also observed for the free form, whose value was not above the olfactory threshold for any sample. MeSA in all its forms also showed a qualitative trend, with MeSA - glucoside and MeSA–primeveroside emphasised in richer cultivars with also a characteristic pattern. The knowledge of the concentration of MeSA glycosides could be considered a potential predictor of the potential evolution of white wines towards balsamic-like nuances.

This work aimed to investigate the occurrence of different monoterpenoids and norisoprenoids in 10 monovarietal Italian red wines (Aglianico, Cannonau, Corvina, Montepulciano, Nebbiolo, Nerello, Primitivo, Raboso, Sangiovese and Teroldego) from 12 regions across Italy. The wines were produced in their terroirs following the oenological practices and legislation of the respective appellation. Data showed that different wine varietals were characterised by peculiar profiles of monoterpenoids and norisoprenoids. Montepulciano and Cannonau wines showed highest levels of nerol, terpinolene, α-terpineol, limonene and of the norisoprenoids β-damascenone, α-ionone, TPB, TDN and vitispirane. Aglianico, Corvina, Nebbiolo and Primitivo were characterised by relatively high levels of linear monoterpene alcohols such as linalool and geraniol. Sangiovese samples from Tuscany could be differentiated from those of Romagna, with the former characterised by a higher content of α-terpinene and the latter of γ-terpinene. The monoterpene 1,4-cineole was present in Montepulciano, Raboso and Sangiovese at potentially relevant olfactory levels, its occurrence associated with higher content of terpinen-1-ol acting as a potential precursor under wine acid conditions.

While red wine phenolics have been extensively studied, polysaccharides and proteins have not received the same level of attention, especially when considering Italian wines. In this study, for the first time, quantitative and qualitative data on the macromolecular (proteins and polysaccharides) and tannin composition of 110 monovarietal red wines from 11 of the most important Italian grape varieties are reported. The winemaking did not include any filtration, oak contact, fining treatments, or ageing on yeast lees. Results highlighted a great inter- and intra- varietal diversity. The protein content ranged between 0 and 159 mg/L, polysaccharides between 211 and 1081 mg/L and total tannins between 171 and 3746 mg/L, with averages of 41 mg/L, 497 mg/L and 1687 mg/L, respectively. Six varieties with protein content representative of the variability observed were selected and submitted to electrophoresis. Within each variety, the SDS-PAGE mobility of protein-tannin complexes was similar but showed two distinct patterns for wines of different varieties (higher mobility for Corvina, Teroldego and Raboso Piave, lower mobility for Nebbiolo, Aglianico, Cannonau), suggesting that the Italian monovarietal wines can be diverse also in their colloidal-forming structures. This can be explained by looking at the different percentages of protein-reactive tannins (TBSA) on the total tannin content (TMCP), which is a varietal characteristic.

Berry texture and berry skin mechanical properties are traits with high agronomic relevance, because they are related to quality parameters and marketing requirements of wine, table, and raisin grapes. Searching for QTLs linked to berry texture, a F1 population of 152 individuals and their parents were used in this study. These F1 plants were obtained crossing ‘Raboso Veronese’, a seeded black wine grape cultivar and ‘Sultanina’, a seedless white grape variety, especially used for raisins. Density flotation was applied for berry sorting improving the management of many and highly variable genotypes, irrespective to the quantification of specific molecules classes. Berries were evaluated for technological ripeness parameters and mechanical properties. Texture parameters were taken as raw data and as data normalized on berry dimensions, i.e. berry diameter or surface or volume. SSR molecular markers were used to produce a genetic map and a major, strong QTL for berry texture was found on chromosome 18 with traits related to berry ‘firmness’ showing a phenotypical explained variance higher than 60%, and traits related to berry resilience, springiness and cohesiveness showing a variance higher than 50%. Surprisingly, this QTL showed to be associated with SSR markers linked to VvAGL11, the main gene linked to seedlessness. VvAGL11 expression and co-expression profiling during grape ripening was evaluated using available information; this data suggested a role for this gene on the texture of a ripe berry.

Berry texture and berry skin mechanical properties are traits with high agronomic relevance because they are related to quality parameters and marketing requirements of wine, table, and raisin grapes. Searching for QTLs linked to berry texture, an F1 population of 152 individuals and their parents were used in this study. These F1 plants were obtained crossing Raboso Veronese, a seeded black wine grape cultivar, and Sultanina, a seedless white grape variety, especially used for raisins. Density flotation was applied for berry sorting improving the management of many and highly variable genotypes, irrespective of the quantification of specific molecule classes. Berries were evaluated for technological ripeness parameters and mechanical properties. Texture parameters were taken as raw data and as data normalised on berry dimensions, i.e., berry diameter or surface or volume. SSR molecular markers were used to produce a genetic map and a major QTL for berry texture was found on chromosome 18 with traits related to berry firmness showing a phenotypical explained variance higher than 60 %, and traits related to berry resilience, springiness and cohesiveness showing a variance higher than 50 %. Surprisingly, this QTL showed to be associated with SSR markers linked to VviAGL11, the main gene linked to seedlessness. VviAGL11 expression and co-expression profiling during grape ripening was evaluated using available information; this data suggested a role for this gene on the texture of a ripe berry. List of Abbreviations: ABW, average berry weight BR, berry resilience BR_diam, berry resilience normalised on berry diameter BR_sur, berry resilience normalised on berry surface BR_vol, berry resilience normalised on berry volume BS_ratio, berry springiness BS_ratio_diam, berry springiness normalised on berry diameter BS_ratio_sur, berry springiness normalised on berry surface BS_ratio_vol, berry springiness normalised on berry volume BCo, berry cohesiveness BCo_diam, berry cohesiveness normalised on berry diameter BCo_sur, berry cohesiveness normalised on berry surface BCo_vol, berry cohesiveness normalised on berry volume BH, berry hardness BH_diam, berry hardness normalised on berry diameter BH_sur, berry hardness normalised on berry surface BH_vol, berry hardness normalised on berry volume BG, berry gumminess BG_diam, berry gumminess normalised on berry diameter BG_sur, berry gumminess normalised on berry surface BG_vol, berry gumminess normalised on berry volume BCh_ratio, berry chewiness BCh_ratio_diam, berry chewiness normalised on berry diameter BCh_ratio_sur, berry chewiness normalised on berry surface BCh_ratio_vol, berry chewiness normalised on berry volume Fsk, berry skin break force Wsk, berry skin break energy Esk, berry skin resistance to the axial deformation Spsk, berry skin thickness

Anthocyanins are extracted from grape skins during maceration and are responsible for the red colour of wine. Their contribution to in-mouth sensations is mainly related to their interactions with condensed tannins, which are largely responsible for wine astringency and mouthfeel-related features. Recently, the influence of several groups of polyphenols, together with other relevant non-phenolic wine constituents,was investigated in terms of their ability to modify the sensory perception of condensed tannins. The aim of this study was to investigate the influence of three acylation groups of anthocyanins (glucoside, acetylglucoside, and p-coumaroylglucoside) extracted from grape skins on in-mouth related features. An extract of total anthocyanins and their individual fractions were tasted using different sensory approaches (triangle test, check-all-that apply and descriptive analysis) and compared to polyphenols extracted from grape skins and seeds. The investigated sensations were overall astringency and astringency sub-qualities, which were divided into two groups: sensation during tasting (in-mouth, particulates) and sensation after expectoration (surface smoothness). Bitterness was also studied. Anthocyanin fractions were added to skin and seed extracts and tasted as mixtures to find out if anthocyanins modify in-mouth perception. Although the anthocyanin fractions showed a low sensory impact, total anthocyanins and the glucoside fraction were perceived at the concentration ranges found in wines (400 mg/L), and they were found to influence astringency intensity and soft astringency sub-qualities, such as “velvety” and “chalky”. The addition of glucoside anthocyanin (400 mg/L) to skin and seed extract (1000 mg/L) modified in-mouth perception; in particular, seed extract was perceived as being more astringent and was characterised by harsher astringency sub-qualities (surface smoothness and particulates). In contrast, the addition of glucoside anthocyanin to the skin extract led to lower surface smoothness, although the intensity of overall astringency was unchanged. These results confirm that the presence of anthocyanins can modify the perception of in-mouth sensations and interact to different extents with other polyphenols, thus leading to the modification of the intensity of astringency and its sub-qualities.

Aim: In this work, seven strains of Starmerella bacillaris were analysed for their ability to release polysaccharides during alcoholic fermentation (AF), both in single-strain and in sequential AF together with Saccharomyces cerevisiae. Methods and Results: A synthetic polysaccharide-free must was used to characterise the mannoproteins (MPs) released. The MPs were quantified, characterised in terms of carbohydrate composition, and tested to assess their ability to reduce protein and tartrate instabilities and their ability to affect the foaming properties of wine. Conclusions: All the tested strains in sequential AF increased the total MPs production. Moreover, the strains affected the MPs properties in different ways regarding tartaric and protein stabilities. The MPs released in sequential AF by some S. bacillaris strains showed a significant effect on protein stabilisation and tartaric stability. An effect on the foamability was found for MPs obtained in single-strain AFs of S. bacillaris. Significance and impact of the study: An improvement in wine stability can be achieved using the sequential AF.

Aims: Fourier Transform-Near Infrared (FT-NIR) spectrum and instrumental texture parameters were assessed as total phenol content and extractability predictors in intact grape seeds. Methods and results:The study was carried out on Cabernet-Sauvignon seeds from grapes harvested at six different advanced physiological stages throughout ripening and calibrated by flotation to reduce the in-field heterogeneity inside each sample. Among the instrumental mechanical properties tested (i. e., break force, break energy, Young’s modulus of elasticity and deformation index), the seed Young’s modulus of elasticity showed an increase during the first four weeks of ripening. This parameter also showed significant correlations with phenol content and extractability, although with low R coefficients. These correlations highlighted that the springier seed tissues greatly increase phenol extractability. Nevertheless, the best prediction of seed phenol content, performed directly on intact seeds, was found using FT-NIR spectroscopy in transmittance mode. The standard error of prediction for total phenol content was less than 8 %, while that for phenol extractability was worse. Conclusion: On the basis of these results, the two analytical methods could be applied in oenology for the rapid monitoring of seed phenolic maturity. Significance and impact of the study: The phenolic composition of grapes at the harvest time is a key factor determining their quality, and thus the quality of the finished wine. The chemical methods used for the determination of seed phenol content and extractability are generally slow because they require a preliminary extraction. Therefore, a rapid evaluation of these parameters could be highly interesting for the oenological sector.

Aims: Phenolic compounds, extractable from grape skins and seeds, have a notable influence on the quality of red wines. Therefore, in this work the phenolic composition of 13 red grape cultivars, grown in one of the most traditional Spanish vine zones, was studied in order to identify significant varietal differences. Methods and results: Anthocyanin concentration and profile, total proanthocyanidin and flavanol contents in berry skins and seeds were determined by spectrophotometric and HPLC methods. The highest concentrations of total anthocyanins was found in the Loureira Tinta, Sousón and Ferrol varieties, while Ferrol was rich in proanthocyanidins in berry skin and Caíño Bravo was rich in proanthocyanidins and flavanols in berry seeds. Malvidin-3-monoglucoside was usually the major anthocyanin. Nevertheless, the anthocyanin profile was characterized mainly of di-substituted molecules for Albarello, Brancellao and Caíño da Terra grapes. Ferrol, Loureira Tinta and Sousón grapes showed the highest values of primitive anthocyanins (delphinidin and petunidin derivatives). Conclusion: Many differences in the phenolic composition of the cultivars studied were found. The results of the phenolic characterization can be utilized in winery in order to apply the most appropriate maceration and winemaking techniques to the processed grapes. Significance and impact of study: Knowledge of the biodiversity of the grape varieties of Galicia (North-West Spain) is still scarce. This study, on phenolic composition, provides oenological information that can be useful to improve the quality of the wines produced.

Aims: This study was designed to gain knowledge of three Controlled Denomination of Origin (DOC) Italian sweet white Passito wines (Caluso Passito DOC, Cinque Terre Sciacchetrà DOC and Passito di Pantelleria DOC) produced in several areas of Italy from grapes dried with different systems and vinification techniques. Methods and results: Physico-chemical and chromatic characteristics, sodium, potassium, gluconic acid, glucono-γ-lactone, acetaldehyde, sorbitol, laccase, organic acids and semi-quantitative free volatile profile were determined on these wines. Caluso Passito DOC wines presented higher contents of organic acids (above all, malic acid), main metabolites from noble Botrytis cinerea (laccase, glycerol, gluconic acid and benzaldehyde) and low contents of total polyphenols. Among the volatile components, normal fatty acid ethyl esters (ethyl hexanoate and ethyl octanoate), branched-chain esters (ethyl 2-methylpropanoate, ethyl 2-methylbutyrate, ethyl 3-methylbutyrate) and benzaldeyde characterized this Passito wine. Cinque Terre Sciacchetrà DOC wines showed the lowest total acidity with a lower amount of malic acid and a higher content of polyphenols. This wine was characterized by some predominant acetates (isoamyl acetate), alcohols, benzaldehyde and an isoprenoid, Β-damascenone. Passito di Pantelleria DOC wines presented higher amounts of ashes resulting in higher pH values compared to the other two Passito typologies. Due to its production from aromatic grapes, it showed several varietal components such as terpenes, while ethyl esters/acetates and alcohols were less represented. Conclusion: This survey provides information allowing the characterisation of three Passito dessert wines at high commercial value. Significance and impact of the study: This study provides oenological information to be utilised to protect and valorise the Controlled Denomination of Origin sweet wine production and contributes to the preservation of traditional and terroir productions and their commercialization.

Aims: The aim of this work was to evaluate the kinetics of anthocyanin extraction in berries of cv Brachetto and Nebbiolo, having the same level of total soluble solids, but with different skin hardness. Methods and results: A puncture test was carried out on berries calibrated according to their density, estimated by flotation in different salt solutions. For each variety, two groups of berries of different skin hardness were selected: soft (< medium value) and hard (> medium value). Spectrophotometric and HPLC methods were used to evaluate the kinetics of anthocyanin extraction in a hydroalcoholic buffer solution. In each of the examined cultivars, the grapes with a higher break skin force produced extracts with a higher content in total anthocyanin. The anthocyanin profile of extracts of Brachetto hard skin is characterized by a higher content of acetyl-glucosides. Conclusion: Texture analysis, which is fast and inexpensive, turned out to be an excellent analytical technique to verify skin hardness measurements. The break skin force proved to be a mechanical parameter able to estimate the extractability of anthocyanins with adequate reliability. Significance and impact of study: The possibility of having an easy way to determine maturity index able to estimate the extractability of phenol compounds with sufficient reliability, can be a valuable tool for the enological community.

Aims: The aim of this work was to study the color of the wine grapes using the CIELAB parameters and to develop colorimetric indexes which can be used as a rapid method to assess the anthocyanin content of the wine grapes in the vineyard. Methods and results: L*, a*, b* parameters were measured by a reflectance spectrophotometer on eighteen red winegrapes at harvest. Two indexes were calculated: CIRG2, used as colorimetric index for table grapes and CIRWG (Color Index for Red Wine Grapes). These indexes showed effective potentialities for descriptive, taxonomic and ampelografic studies. Particularly the CIRWG index is more correlated to the total anthocyanin amount, while the CIRG2 is more correlated to the different forms of the anthocyanins. Conclusion: The colorimetric indexes applied directly in the vineyard permit to assess the total anthocyanin content and to give further quickly information on grape quality and maturity. Significance and impact of study: The development of analytical methods for the evaluation of anthocyanin immediates, easily applicable, at low cost in the field by grape-growers and winemakers, can be very useful in deciding the harvest date.