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This study aimed to investigate the physico-chemical characteristics of "reisa" red winegrapes from five growing areas at three ripeness degrees. Wines were produced with grapes from each growing area. Results highlighted that "Freisa" grapes have relatively hard skins (break force>0.8 N), medium anthocyanin content (>800 mg/kg grapes), and high flavanol content (PRO>2500, FVA>1200 mg/kg grapes). Skin thickness, total anthocyanin and flavanol contents were significantly influenced by environmental conditions and ripeness. Grapes from Monferrato area showed the thickest skins and highest contents of anthocyanins but also of seed flavanols. Coherently, wine color characteristics and phenolic composition depended on growing area. [ABSTRACT FROM AUTHOR]

Seed mechanical properties were instrumentally measured by compression testing in thirty white and red wine grape varieties at harvest. The effect of berry heterogeneity in a vineyard on these seed texture parameters was also evaluated to improve the understanding of intra-sample variability. Furthermore, the mechanical properties of the seeds were assessed as possible predictors of their phenolic extractability. The results show that the texture parameters of the seeds are independent of the location of the berry in the vineyard and the soluble solid content at harvest. Densimetric flotation of the berries permits the reduction of the intra-sample variability that could hinder the differentiation and/or classification of wine grape varieties according to seed mechanical attributes. Cluster analysis classified the wine grape varieties studied into three groups according to seed hardness (low: 32.51 to 40.80 N, intermediate: 42.84 to 44.99 N, high: 46.71 to 57.78 N). The relationships between the seed mechanical properties and the extractable content of phenolic compounds, determined by spectrophotometric and chromatographic reference chemical methods, were evaluated by means of correlation analysis. Linear regression calibration models were developed for each cluster. The statistical parameters highlighted that total flavonoids, proanthocyanidins and flavanols reactive to vanillin can be predicted successfully from the seed mechanical properties for the varieties having low and intermediate seed hardness (SEC% ca. 20, RPIQ > 1.6). For varieties with harder seeds, a satisfactory predictive accuracy seems to require the construction of separate calibration models for each cultivar (Nebbiolo, SEC% ca. 20, RPIQ > 2.2). [ABSTRACT FROM AUTHOR]

The phenolic composition and extractability indices of grape berries play a key role in assessing red wine quality because the relationship between grape phenolic maturity and wine phenolic composition is well known. In this work, grape quality indices were determined in Nebbiolo grapes from two growing areas of Langhe (South Piedmont), at different stages throughout the ripening process in six consecutive years (2004 to 2009), with the aim of evaluating the ripening- and growing area-related changes in the grape indices separately. The effect of vintage was also investigated. Ripeness data were compared with analogous data determined in Nebbiolo grapes grown in the Carema area (North Piedmont). The vintage effect far outweighed any changes in the grape indices introduced by the ripening stage, even those arising from differences in the production area. In the Langhe and Carema zones, the average berry mass, pH, total acidity, total anthocyanins extractable at pH 3.2, total flavonoids and non-anthocyanin flavonoids extractable at pH 1, and the seed maturity index were seasonally dependent. The more ripening-affected parameters were the technological ones. This work highlights the importance of determining the phenol extractability, since it provides relevant information that allows improved management of the maceration stage. [ABSTRACT FROM AUTHOR]

Cold liquid stabulation aims to extract valuable compounds from grape lees before juice clarification. In this study, 7, 14, and 21 days of lees contact were tested on aroma-neutral 'Arneis' and 'Cortese' grape juices vs control. Basic parameters, colour, polyphenols, antioxidant capacity, and volatile organic compounds were assessed throughout winemaking. Wine sensory analysis was performed. The produced wines did not differ in terms of colour and show limited differences in polyphenols, not influencing astringency and bitterness. Variety and treatment length influenced free and glycosylated volatile organic compounds. Free terpenes increased in the 21-day treated 'Arneis' wine (+67 %). Lower free esters in 'Arneis' with 14 days of stabulation were found (-10 %). On the contrary, higher values of individual esters were found in 14 and 21-day treated 'Cortese' wines, but these showed lower free C6 (-12 %) and sulphur compounds (-23 % and - 24 %, respectively), and higher overall wine quality with respect to non-stabulated wine., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The perceived aroma is the result of the presence of volatile organic compounds (VOCs) as well as the interaction among them and with the nonvolatile sample matrix. These compounds can derive from grape berries (varietal) and also be formed during winemaking and aging processes. Varietal VOCs are strongly influenced by the grape variety, ripening, and geographical origin. Therefore, they were proposed as markers for wine discrimination. Nevertheless, recent studies highlighted the higher discriminating ability of VOC isomer forms. In this review the potential and importance of VOC isomers for terpenes, C 13 -norisoprenoids, C 6 -alcohols, thiols, lactones, and fatty acid esters, as well as isomeric relationships for wine characterization and differentiation have been described to get a full view of possible applications for the wine industry, highlighting potentialities and limitations. VOC isomers can be of paramount relevance to find reliable markers for wine authenticity and fraud prevention, regarding variety and geographical origin. Each isomer form owns a different olfactory threshold, influencing strongly wine sensory characteristics. Certain oenological treatments during winemaking and aging were found to modify the isomeric profile, particularly yeasts, aging, and wood in contact with wine. Nevertheless, this research field has potential and new research advances are expected in this field.

The impact of seeds on anthocyanin extraction from skins was assessed on four Italian red winegrape varieties presenting different anthocyanin profile. Grape skins were macerated alone or in presence of seeds for ten days in model solutions. Aglianico, Nebbiolo, Primitivo, and Sangiovese cultivars showed differences in the anthocyanin extraction rate, content, and profile. The presence of seeds did not significantly affect the anthocyanin content and forms extracted from skins and kept into solution, but it generally led to an increase in the polymerization rate. For the first time, anthocyanins adsorbed on seed surface have been quantified after maceration. The amount of anthocyanins retained by seeds was less than 4 mg/kg berries and it seems variety-dependent, with a possible role of seeds number and weight. Individual anthocyanin forms were adsorbed mainly according to their abundance in the solution, but cinnamoyl-glucoside anthocyanin forms showed a higher affinity with seed surface., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The effects of size, toasting degree, and time of contact on the release of volatile compounds from Quercus alba (L.) chips during a simulated fermentation and post-fermentative process were studied. The results obtained indicated that the large-size chips favored the release of furfural and furfuryl alcohol, while the small ones increased the concentration of cyclotene and maltol. The interaction between chip size and time of contact showed that the small-size chips are more sensitive to the increase of ethanol concentration for the extraction rate of some compounds (furfural, vanillin, maltol, cyclotene, whiskey lactones, and eugenol) compared to the large-size ones, increasing their concentrations at the end of maceration. The toasting degree of oak chips had a different influence on the volatile compounds studied. Cyclotene and guaiacol concentrations increased with the toasting intensity, whereas the extracted concentration of all compounds increased from light to medium-toasted chips, except for eugenol, and then decreased by further increasing the toasting level for 5-methylfurfural, whiskey lactones, eugenol, and only using high-level toasted chips for furfuryl alcohol, maltol, and vanillin. A possible protection effect of the chip size toward the possible degradation or volatilization losses of furfural for high toasting degrees was observed.

Background: Sforzato di Valtellina (Sfursat) is a PDO reinforced red wine produced in Valtellina (northern Italy) from partially withered red grapes (Vitis vinifera L.) cv. Nebbiolo. The present study aimed to evaluate the combined influence of different grape ripeness levels and withering length on the chemical composition, mechanical properties, and phenolic profile of Nebbiolo winegrapes from two Valtellina vineyards. During three consecutive vintages (2019, 2020, and 2021), three different technological binomials have been tested: early harvest/long withering (EL), medium-term harvest/medium-term withering (MM), and late harvest/short withering (LS)., Results: At the end of the withering process, EL thesis usually presented the highest values of sugars and acidity. Extractable seed polyphenols showed a decreasing trend by leaving the grapes on the plant longer, and this effect increased considerably after withering with respect to fresh samples. EL and MM evidenced the greater concentration of these compounds expressed on grape weight, particularly for tannins. Instead, skin-extracted total phenolics were less influenced by the harvest time, whereas their concentration increased after withering. The harvest time appears to have a higher impact than the withering length on the final extractable anthocyanin content, although the trend was no stable during the vintages or common for the two vineyards evaluated. EL and MM experienced the highest contents of grape skin tannins in most cases, suggesting that a longer withering increases their concentration., Conclusion: Harvest time and withering length can be modulated according to the desired oenological objective, promoting the valorization of grape potentialities. The choice to harvest the grapes earlier and enhance the withering length should be preferred to obtain wines with higher acidity and phenolic content, more suitable for long-ageing period. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry., (© 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.)

Astringency and more generally mouthfeel perception are relevant to the overall quality of the wine. However, their origin and description are still uncertain and are constantly updating. Additionally, the terminology related to mouthfeel properties is expansive and extremely diversified, characterized by common traditional terms as well as novel recently adopted descriptors. In this context, this review evaluated the mention frequency of astringent subqualities and other mouthfeel attributes in the scientific literature of the last decades (2000-August 17, 2022). One hundred and twenty-five scientific publications have been selected and classified based on wine typology, aim, and instrumental-sensorial methods adopted. Dry resulted as the most frequent astringent subquality (10% for red wines, 8.6% for white wines), while body-and related terms-is a common mouthfeel sensation for different wine types, although its concept is still vague. Alongside, promising analytical and instrumental techniques investigating and simulating the in-mouth properties are discussed in detail, such as rheology for the viscosity and tribology for the lubrication loss, as well as the different approaches for the quantitative and qualitative evaluation of the interaction between salivary proteins and astringency markers. A focus on the phenolic compounds involved in the tactile perception was conducted, with tannins being the compounds conventionally found responsible for astringency. Nevertheless, other non-tannic polyphenolic classes (i.e., flavonols, phenolic acids, anthocyanins, anthocyanin-derivative pigments) as well as chemical-physical factors and the wine matrix (i.e., polysaccharides, mannoproteins, ethanol, glycerol, and pH) can also contribute to the wine in-mouth sensory profile. An overview of mouthfeel perception, factors involved, and its vocabulary is useful for enologists and consumers., (© 2023 The Authors. Comprehensive Reviews in Food Science and Food Safety published by Wiley Periodicals LLC on behalf of Institute of Food Technologists.)

In this work, we assessed the effect of a biosurfactant extract, which possesses preservative properties, on the sensory properties, regarding colour, of two fruit juices: pasteurized apple juice and natural orange juice. This biosurfactant extract was obtained from corn steep liquor, a secondary stream of the corn wet-milling industry. The biosurfactant extract is composed of natural polymers and biocompounds released during the spontaneous fermentation of corn kernels during the steeping process of corn. The reason for this study is based on the importance of colour as a visual attribute that can determine the consumer's preferences; it is important to study the effect of the biosurfactant extract under evaluation before including it in juice matrices. For this, a surface response factorial design was employed and the effects of the biosurfactant extract concentration (0-1 g/L), the storage time (1-7 days), and the conservation temperature (4-36 °C) on the CIELAB colour parameters (L*, a*, b*) of the juice matrices were evaluated, as well as the total colour differences (ΔE*) regarding the control juices and the saturation index (Cab*). Moreover, the CIELAB coordinates of each conducted treatment were converted into RGB values to obtain visual colour differences that can be appreciated by testers or consumers.

Fungi and oomycetes found in vineyards cause diseases such as powdery and downy mildew. Consequently, conventional and alternative agronomical practices are widely used prior to harvest to protect grapes. Alternative products are considered more eco-friendly and environmentally sustainable in comparison to conventional chemical products. However, the effect of these alternative products on yeast ecology, from the vineyard to the winery, is poorly understood. This study compared the effect of alternative and conventional chemical antifungal compounds (copper and sulphur based) on grapes' mycobiota in the vineyard and during subsequent winery fermentation using culture-dependent and -independent approaches. Culture-dependent data indicated a treatment-dependent effect on the load and diversity of yeast populations on grapes. It was found that the population of Hanseniaspora uvarum was higher on grapes previously treated with laminarin and copper, compared to the other levels registered on grapes previously treated with the rest of antifungal products tested in this study (including the untreated and conventional treatment controls). Concerning, wine quality, the chemical composition was not correlated to the application of antifungal treatment in the vineyard. Understanding the effect of different antifungal products on grape and wine microbial communities may help in setting up guidelines for wine grape production. These guidelines, can be used to guarantee quality in the pursuit of a sustainable competitive advantage in the market., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Oenological tannins (OETs) are winemaking processing aids used to facilitate stabilization and fining, to increase the antioxidant capacity, and to promote colour stability of grape juice and wine. A wide variability of pure or mix formulates are available for winemaking purposes, including hydrolysable tannins (gallotannins and ellagitannins), proanthocyanidins from grape skins and seeds (prodelphinidins and procyanidins), and from exotic wood (prorobinetinidins and profisetinidins). In this study, seventeen OETs pure and mix formulates were characterized in terms of polyphenolic content and antioxidant capacity in a model wine and in a red wine after one-month storage, as well as aroma, astringency, and bitterness sensory characteristics in water and red wine. Colour-related features were also analysed in the added red wine after one-month storage. For the first time, correlations among the obtained results in the different matrices were investigated to understand the most suitable OETs for winemaking applications. The results showed a great variability among the formulates studied in terms of phenolic content, which was strictly correlated to their antioxidant capacity. Regarding origin, hydrolysable tannins had the highest antioxidant ability, followed by exotic wood formulates. A strong and positive correlation was found in antioxidant capacity of OETs in model wine and red wine after one-month storage, in particular for ellagitannins, which confirmed also their ability to increase pigments polymerization. By contrast, quebracho tannins resulted the bitterest and most astringent when tasted in water (0.4 g/L), although in-mouth and aromatic descriptors of OETs tasted in water were not correlated with the ones of the added red wine. Therefore, the choice of OETs formulate and its optimal dose requires a characterization in terms of polyphenolic content and antioxidant capacity because these properties were well correlated with those of the added wines in a short storage period, whereas the sensory impact at oenological range doses is mainly dependent on wine features., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

'Nebbiolo' is a well-known grapevine variety used to produce prestigious monovarietal Italian red wines. Genetic traceability is an important tool used to protect the authenticity of high-quality wines. SNP-based assays are an effective method to reach this aim in wines, but several issues have been reported for the authentication of commercial wines. In this study, the impact of the most common commercial additives and processing aids used in winemaking was analysed in 'Nebbiolo' wine using SNP-based traceability. Gelatine and bentonite had the strongest impact on the turbidity, colour and phenolic composition of wines and on residual grapevine DNA. The DNA reduction associated with the use of bentonite and gelatine (>99% compared to the untreated control) caused issues in the SNP-based assay, especially when the DNA concentration was below 0.5 pg/mL of wine. This study contributed to explaining the causes of the reduced varietal identification efficiency in commercial wines., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

An extensive survey was conducted on 110 Italian monovarietal red wines from a single vintage to determine their standard compositional, color, and phenolic characteristics, analysing more than 35 parameters evaluated through methods commonly used in the wine industry. 'Primitivo' achieved the highest average alcohol strength (15.4% v/v) and dry extract values, while 'Cannonau' showed the lowest total acidity. 'Corvina' had the lowest phenolic content (1065 mg/L by Folin-Ciocalteu assay), remarkably different from the highest found in 'Sagrantino' (3578 mg/L), the latter being also the richest variety in both proanthocyanidins and vanillin-reactive flavanols. 'Teroldego' wines were the richest in both total and monomeric anthocyanins (702 and 315 mg/L, respectively), followed by 'Aglianico' and 'Raboso Piave', while 'Corvina', 'Nebbiolo', and 'Nerello Mascalese' were the poorest. 'Montepulciano' and 'Sangiovese' showed intermediate values for the majority of the parameters analyzed. A multivariate PCA-DA approach allowed achieving both a classification of the different wines as well as the discrimination of 'Sangiovese' wines produced in two regions (Emilia Romagna and Toscana) that returned a 42-66% success rate depending on the zone considered. Taking into account the number and diversity of the wines analyzed, a correlation study helped in better understanding the underlying relations between the most common and widespread analytical techniques for phenolic and color determinations., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

In winemaking, oenological tannins are used to preserve wine colour by enhancing the antioxidant activity, taking part in copigmentation, and forming polymeric pigments with anthocyanins. As a novel processing aid, in this study, a biosurfactant extract was evaluated as a solubilizing and stabilizing agent of anthocyanins in red wine. The biosurfactant extract under evaluation was obtained from a fermented residual stream of the corn milling industry named corn steep liquor (CSL). Two red winegrape varieties ( Vitis vinifera L. cv. Aglianico and Cabernet sauvignon) were studied for anthocyanin content and profile, and colour traits, during simulated skin maceration for 7 days at 25 °C, as well as polymerization and copigmentation at the end of maceration. A model wine solution was used as a control, which was added either with the CSL biosurfactant or with four different oenological tannins (from grape skin, grape seed, quebracho, and acacia). The results showed that CSL biosurfactant addition improved the colour properties of skin extracts by the formation of more stable compounds mainly through copigmentation interactions. These preliminary results highlighted that the effectiveness of CSL biosurfactant is variety-dependent; however, there is no significant protection of individual anthocyanin compounds as observed for delphinidin and petunidin forms using quebracho tannin.

In this study, the combined effect of partial postharvest dehydration and long-term ozone treatment was evaluated at 10 and 20% weight loss as a strategy to induce compositional changes in grape skin flavanols. Two separate trials were carried out in thermohygrometric-controlled chambers at 20 °C and 70% relative humidity. The first trial was conducted under an ozone-enriched atmosphere at 30 μL/L, whereas the second trial was performed under an air atmosphere as a control. Two red wine grape varieties were studied, Barbera and Nebbiolo ( Vitis vinifera L.), for their different phenolic composition. Berry skin flavanol composition was determined by high-performance liquid chromatography after phloroglucinolysis and size-exclusion chromatography. The results showed that dehydration and ozone effects were variety-dependent. In Barbera skins, being characterized by lower proanthocyanidin contents, the two effects were significant and their combination showed interesting advantages related to lower proanthocyanidin loss as well as higher prodelphinidin and lower galloylation percentages. In Nebbiolo, skin flavanol composition was barely affected.

Recently the use of electrolyzed water (EW) attracted much attention as a high-performance, new technology for its potential use in the food industry. The aim of this work was to investigate the impact of grape EW treatments, applied at different time intervals prior to harvest, on the indigenous yeast populations of grape surface (Chenin blanc and Cabernet franc) and the occurrence of 2,4,6-trichloroanisole (TCA) in Cabernet franc wine. In addition, the evolution of inoculated and spontaneous fermentations on treated and non-treated grapes was also considered. The yeast population present on grape berries surface was influenced in a grape variety and EW treatment time-dependent way, since only Chenin blanc grapes treated with EW 7 days prior to harvest had significantly lower yeast population levels, compared to the respective control. Concerning the yeast diversity in the grape samples, a dominance of Aureobasidium pullulans was observed in treated grapes, independently of the grape variety. At the end of alcoholic fermentation, 2,4,6-trichloroanisole was detected in wine when the EW solution was applied at one or two weeks before harvest time. After wine storage, 2,4,6-trichloroanisole and chlorophenols contents generally exhibited a loss relative to initial values. The results showed that EW treatments tended to slightly increase the TCA concentration in final wine and did not affect the fermentation performances and chromatic properties of resulting wine. On the other hand, absorption or desorption phenomena by wine lees could be involved in the change of 2,4,6-trichloroanisole concentration in wine during storage time., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

This work aims to improve the management of the malolactic fermentation (MLF) in red wines by elucidating the interactions between Starmerella bacillaris and Saccharomyces cerevisiae in mixed fermentations and malolactic bacteria. Two Starm. bacillaris strains were individually used in mixed fermentations with a commercial S. cerevisiae. MLF was performed using two autochthonous Lactobacillus plantarum and one commercial Oenococcus oeni inoculated following a simultaneous (together with S. cerevisiae) or sequential (at the end of alcoholic fermentation) approach. The impact of yeast inoculation on the progress of MLF was investigated by monitoring the viable microbial populations and the evolution of the main oenological parameters, as well as the volatile organic composition of the wines obtained in mixed and pure micro-scale winemaking trials. Our results indicated that MLF was stimulated, inhibited, or unaffected in mixed fermentations depending on the strains and on the regime of inoculation. O. oeni was able to perform MLF under all experimental conditions, and it showed a minimal impact on the volatile organic compounds of the wine. L. plantarum was unable to perform MLF in sequential inoculation assays, and strain-depending interactions with Starm. bacillaris were indicated as factor affecting the outcome of MLF. Moreover, uncompleted MLF were related to a lower aromatic complexity of the wines. Our evidences indicate that tailored studies are needed to define the appropriate management of non-Saccharomyces and malolactic starter cultures in order to optimize some technological parameters (i.e. reduction of vinification time) and to improve qualitative features (i.e. primary and secondary metabolites production) of red wines., Competing Interests: Declaration of Competing Interest The authors declared that there is no conflict of interest., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

In winemaking, exogenous tannins are added before maceration to improve future wine color characteristics derived from extracted grape anthocyanins. The study aimed to investigate the relation between different grape varieties, selected according to their anthocyanin profile, and the effect of five exogenous tannin formulations differing in origin and chemical features. Anthocyanin content, polymeric pigments, and color traits were assessed during a 72-hour skin simulated maceration. Grape skin-derived tannins increased color intensity (up to one unit) and polymeric pigments formation (up to 6.5%) in malvidin-prevalent Merlot and Cabernet sauvignon, with different extent depending on the anthocyanin richness. Grape seed-derived and ellagic formulations favored the pigment polymerization, the first in Nebbiolo and Sangiovese (up to 8.2%), which are characterized by high ratios of disubstituted anthocyanins, and the latter in malvidin-rich Syrah and Aglianico (up to 5%). A positive effect of quebracho regarded the defense of anthocyanin forms, particularly in Sangiovese and Nebbiolo., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Viticulture is a cropping system in which treatment against fungal diseases (in particular powdery and downy mildews) can be extremely frequent. Accordingly, a reduction in antimicrobial treatments and the application of environmentally-friendly compounds are becoming increasingly important for a more sustainable viticulture. In addition to their effect against pathogens, the impact of these products on the quality of the grapes is very important for the oenological industries, but unfortunately at present few data are available. We evaluated the effect of the application of biocontrol products and resistance inducers in the vineyard on the mechanical properties, microbial ecology, technological and phenolic maturity of Vitis vinifera "Nebbiolo" grapes at harvest. The yield and vigor of vines were not influenced by the treatments, nor were the production of primary and secondary metabolites. However, the active ingredients influenced the mechanical properties of the skin (hardness and thickness). A significant hardening of the skin was detected when laminarin and chito-oligosaccharides were used, and sulfur induced a thickening of the skin with potential consequences for wine quality. Furthermore, the yeast community present on grape berries was influenced by the treatments. The abundance of Aureobasidium pullulans , the dominant species on the grape berry, changed in response to the compounds used. In addition, Alternaria sp. was reduced in some treatments with a potentially positive effect on the quality and the safety of the grapes. This study provides an overview of the effect of biocontrol products and resistance inducers on microbial ecology and "Nebbiolo" grape quality, contributing to the establishment of more sustainable and effective defense strategies in viticulture., (Copyright © 2020 Rantsiou, Giacosa, Pugliese, Englezos, Ferrocino, Río Segade, Monchiero, Gribaudo, Gambino, Gullino and Rolle.)

Plant proteins have been proposed as an alternative to animal-origin proteins in the wine industry because they are allergen-free and vegan-friendly. The aim of this study was to evaluate the effectiveness of plant proteins as fining agents on red wines with different phenolic composition. Two formulations for commercially available vegetal proteins (potato and pea origin) were assessed at two doses to modulate the fining treatment to the wine phenolic profile. The results evidenced that fining agents derived from plants have different levels of effectiveness on the removal of phenolic compounds depending on the origin, the formulation used, dose applied, and also wine characteristics. On Nebbiolo wine, the study was particularly significant due to its phenolic composition. One pea-based fining agent had an effect comparable to gelatin (animal origin) on the removal of polymeric flavanols with a minor loss of anthocyanins and therefore better preserving the wine color in terms of intensity and hue. For Primitivo, Montepulciano, and Syrah wines, even though there was a formulation-dependent effect, vegetal proteins gave more balanced reductions in terms of target phenolic compounds contributing to astringency and color perception.

Background: The possible agricultural use of grape pomace could be limited by the content and mobility of metals. This is influenced by many factors. In this study, the abundance and availability of heavy metals and essential nutrients were evaluated comprehensively in different grape pomace residues from winemaking of five white and red grape varieties, before and after the distillation process., Results: The total metal content found in grape pomace skins and seeds confirmed that there was greater metal accumulation in skins than in the corresponding seeds, with the exception of Ca and Mg. The enrichment of all metals (except K) during the distillation stage was confirmed by means of a significant correlation (R = 0.996, P < 0.001) between the metal content obtained in distilled and undistilled samples. Regarding availability, multivariate statistical analysis showed different behavior among elements, but a great similarity for metal mobility in both distilled and undistilled grape pomace samples and in both skins and seeds, except for Mn, Zn and Mg., Conclusion: The results obtained in this study suggest the potential application of these grape residues as organic fertilizers for agricultural soils, without limitations resulting from heavy metal contamination. © 2019 Society of Chemical Industry., (© 2019 Society of Chemical Industry.)

Stilbenes, including trans-resveratrol and its derivatives, are compounds naturally present in grapes and have gained a growing interest due to reported health-promoting properties. The production of resveratrol-enriched table grapes has promoted recent research on stress-induced synthesis of stilbenes. The oxidizing properties of ozone have been successfully exploited to its use as sanitizing agent and stilbene elicitor during table grapes storage. In winegrapes, this study represents the first research focused on the effect of postharvest ozone treatments on the accumulation of stilbene compounds. The study was carried out on Moscato bianco winegrapes (Vitis vinifera L.) and several gaseous ozone treatments were investigated differing in ozone dose (30 and 60 μL/L), exposure time (24 h, 48 h, and several days until 30% of weight loss), and delay time until processing (just after and several days after treatment). The stilbene production induced by ozone exposure was assessed in fresh and partially dehydrated winegrapes up to 5, 10, 15, 20, and 30% of weight loss aiming to evaluate the single and combined effect of oxidative and osmotic stresses. The results obtained showed that short-term exposure of fresh winegrapes at 60 μL/L of ozone for 48 h was not effective in inducing resveratrol accumulation just after treatment, but it had an elicitor effect on total stilbenes (+36%) in grapes subsequently dehydrated up to 20% of weight loss with a significant overproduction of trans-resveratrol and trans-piaceatannol. In addition, long-term and continuous treatments under ozone-enriched atmosphere can be also used during dehydration to sanitize winegrapes without affecting negatively the concentration of stilbenes. Therefore, the use of gaseous ozone during storage and dehydration could be indicated to reduce the use of sulfur dioxide and, depending on ozone dose and exposure time, the synthesis of stilbene compounds could increase., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

In recent years, there is an increasing interest from the winemaking industry for the use of mixed fermentations with Starmerella bacillaris (synonym Candida zemplinina) and Saccharomyces cerevisiae, due to their ability to modulate metabolites of oenological interest. The current study was carried out to elucidate the effect of this fermentation protocol on the growth and malolactic activity of lactic acid bacteria (LAB) used for malolactic fermentation (MLF) and on the chemical and volatile profile of Nebbiolo wines and their chromatic characteristics. To this end, two LAB species, namely Lactobacillus plantarum and Oenococcus oeni, were inoculated at the beginning and at the end of the alcoholic fermentation (AF) performed by pure and mixed yeast using the abovementioned yeasts. The different yeast inoculation protocols and the combination of species tested influenced greatly the interactions and behavior of the inoculated yeasts and LAB during AF and MLF. For both LAB species, inoculation timing was critical to how rapidly MLF started and finished. Fermentation inoculated with L. plantarum, at the beginning of the AF, completed MLF faster than those inoculated with O. oeni. The presence of Starm. bacillaris in mixed fermentation promoted LAB growth and activity, in particular, O. oeni. Furthermore, LAB species choice had a greater impact on the volatile and chromatic profile of the wines than inoculation time. These findings reveal new knowledge about the importance of LAB species choice and inoculation time to ensure fast MLF completion and to improve wine characteristics in mixed fermentation with Starm. bacillaris and S. cerevisiae.

The use of Starmerella bacillaris in combination with Saccharomyces cerevisiae is considered as a state-of-the-art biological application to modulate wine composition. This application implies a detailed understanding of yeast-yeast interactions during mixed fermentations and their effect on the composition of the resulting wines. In this context, ten commercial S. cerevisiae strains were used as partners of an indigenous, previously characterized Starm. bacillaris strain in order to get a better insight into the impact of S. cerevisiae strain employed. The different combinations of strains tested influenced the growth dynamics, the fermentation behavior and, as a consequence, wine composition in a couple-dependent manner. In addition, wines produced from mixed fermentations had significantly lower levels of ethanol, acetic acid and ethyl acetate, and showed higher amounts of glycerol, higher alcohols and esters compared to pure S. cerevisiae control fermentations. This study reveals the importance of S. cerevisiae strain choice on the chemical composition of the wines produced from mixed culture fermentations with Starm. bacillaris., (Copyright © 2019 Elsevier Ltd. All rights reserved.)