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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.)

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.)

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 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.)

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.)

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.)

Background: Cane-cut on-vine withering is a grape dehydration technique used for dry and sweet wine production. The aim of this work was to study the influence of the cane-cut technique applied at harvest to Moscato bianco grapes during the on-vine withering process to produce dehydrated berries with a different chemical composition and a volatile profile., Results: After 24 days of dehydration, an on-vine withering system using the cane-cut technique induced an increase in the total volatile content compared with grapes produced with a normal on-vine withering process. This increase was greater in glycosidically bound volatile compounds than in the free fraction. Bound linalool showed a significant increase of 52% when the cane-cut withering system was applied but the grapes that were normally withered appeared to be less prone to the loss of free linalool. A significant increase in the glycosylated forms of nerol and geraniol was also observed in the two on-vine withering systems on the 24th day compared with the control (fresh grapes at harvest date)., Conclusion: A cane-cut, on-vine withering system applied at harvest induced changes in the volatile composition of Moscato bianco grapes increasing total volatile content, consisting mainly of bound compounds, by the 24th day of dehydration. The grapes dehydrated on-vine using this new system also showed significantly greater content of most of the free volatile compounds detected. © 2018 Society of Chemical Industry., (© 2018 Society of Chemical Industry.)

Foliar treatments using two products based on Saccharomyces cerevisiae inactive dry yeast derivatives with specific formulations for white and red varieties were tested in two consecutive vintages on Vitis vinifera L. cv. Chardonnay, Cortese, and Nebbiolo grown in Piedmont (north-west Italy). The possible elicitor effect of the foliar treatment was assessed at harvest on the chemical composition and mechanical properties of grape berries. The accumulation and extractability of phenolic compounds in Nebbiolo grape skins were also studied. Wines were produced and analysed in terms of technological parameters, color characteristics, free volatile composition, and phenolic compounds. The treatments induced an +16 μm average increase in berry skin thickness, which makes the grapes more resistant to physical damages and pathogenous attacks. In Nebbiolo, this treatment enhanced the accumulation of anthocyanins (+33 mg/kg on average). However, the obtained results pointed out a vintage effect. In 2015, few significant differences between wines made from control and treated grapes were found. Instead, in 2016, Nebbiolo treated wines had a slightly worse chromatic quality as a consequence of lower contents of phenolic compounds, but they were richer in relative amounts of malvidin-3-glucoside., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Gaseous ozone has been recently proposed as sanitizing agent to control mycobiota on grapes. The aim of this work was to evaluate the impact of ozone treatment during winegrapes dehydration (10 and 20% weight loss) on the content of phenolic compounds after treatment and their extractability during simulated maceration. The results showed that the ozone effect depends on the profile and content of anthocyanins and flavanols. For varieties characterized by prevalence of di-substituted anthocyanins and high flavanol contents, no significant differences were observed in phenolic compounds contents, but lower anthocyanin extractability was found. Instead, for varieties rich in anthocyanins and with a tri-substituted prevalent profile, lower anthocyanin contents were found at 20% WL, but their extractability was significantly increased. Using multivariate analysis, the extractability was correlated with skin cell wall composition and mechanical properties. Proteins, non-cellulosic glucose and total phenols contributed mainly to explain phenolic compounds extractability in withered grapes., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Ozone, a powerful oxidative stressor, has been recently used in wine industry as sanitizing agent to reduce spoilage microflora on grapes. In this study, we evaluated ozone-induced metabolic and molecular responses during postharvest grape dehydration. Ozone increased the contents of total volatile organic compounds (VOCs), which have a great impact on the organoleptic properties of grapes and wines. Among terpenes, responsible for floral and fruity aroma, linalool, geraniol and nerol were the major aromatic markers of Moscato bianco grapes. They were significantly affected by the long-term ozone treatment, increasing their concentration in the last phases of dehydration (>20% weight loss). At molecular level, our results demonstrated that both postharvest dehydration and ozone exposure induce the biosynthesis of monoterpenes via methylerythritol phosphate (MEP) pathway and of aldehydes from lipoxygenase-hydroperoxide lyase (LOX-HPL) pathway. Therefore, transcriptional changes occurred and promoted the over-production of many important volatile compounds for the quality of white grapes.

Moscato nero d'Acqui is an Italian aromatic black winegrape variety characterized by a low content of anthocyanins (mostly tri-substituted), a satisfactory content of high molecular mass tannins, and a fair amount of terpenes. The grapes were subjected to a postharvest dehydration process under controlled thermohygrometric conditions (16-18°C, 55-70 RH%, 0.6m/s air speed) with the aim to produce three different special wine types (fortified, sfursat, and passito) from fresh, partially dehydrated (27°Brix), and withered (36°Brix) grapes, respectively. Chemical traits of produced grapes and wines were then evaluated through spectrophotometric, HPLC, and GC-MS methods. Increased contents of skin phenolic compounds and reduced extractable contents of seed phenolic compounds were observed as dehydration progressed. Few significant differences were found in the anthocyanin profile of grapes, although the relative abundance of coumaroylated anthocyanins was higher in dehydrated grapes. The predominant free volatile compound found in grapes was geraniol, which decreased with increasing water loss, whereas the contents of major glycosylated volatile compounds increased even above the concentration effect. The changes in the phenolic composition among wines agreed with those among grape skins. Fortified wines were chromatically unsatisfactory probably due to the low content of total anthocyanins, whereas sfursat and passito wines meet good chromatic characteristics as a result of the concentration effect during grape dehydration. Fortified and sfursat wines had free aroma profiles richer in 2-phenylethanol and citronellol, whereas passito wines were mainly composed of 2-phenylethanol and 2-phenylethyl acetate, citronellol being the predominant terpenol in all the wine types studied., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Recently the use of ozone as sanitizing agent has been proposed on winegrapes in order to control mycobiota after harvest. The aim of this work was to investigate possible indirect physico-chemical effects of ozone treatment on berry skin phenolic composition and extractability. Vitis vinifera L. cv Nebbiolo and Barbera, chosen for their different anthocyanin profiles, were post-harvest treated for 24 and 72h with gaseous ozone (30μL/L). Skin anthocyanin and flavanol extractability was assessed during maceration (6, 24, 48, 96, 168 and 240h) using a wine-like solution. In our experimental conditions, ozone did not affect significantly the final extraction yield of anthocyanins (TA), proanthocyanidins (PRO), and flavanols reactive to vanillin (FRV) in Barbera, although TA and FRV extractabilities were higher in control samples than in ozone-treated samples during the first stages of maceration. In Nebbiolo, the final TA extraction yield was positively influenced by the ozone treatment (68.6, 64.2, and 59.9% for 24h ozone-treated berries, 72h ozone-treated berries and control samples, respectively). Final PRO and FRV extractability also increased in both ozone-treated samples compared to the control (+8.6-9.1% for PRO and +7.3-11.7% for FRV). No significant differences were found among treatments for individual anthocyanins in both cultivars at the end of maceration. Therefore, the use of ozone as sanitizing agent in red varieties prior to winemaking process can be considered because it did not negatively affect the extractability of skin anthocyanins and flavanols., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

The impact of postharvest dehydration on the volatile composition of Malvasia moscata grapes and fortified wines produced from them was assessed. The ripeness effect of fresh grapes on volatile compounds of dehydrated grapes was evaluated for the first time in this study. Fresh grape berries were densimetrically sorted, and more represented density classes were selected. Dehydration of riper berries (20.5 °Brix) led to volatile profiles richer in terpenes, particularly linalool and geraniol. The effect of dehydration rate on the volatile composition of dehydrated grapes and fortified wines was also evaluated. Fast dehydration grapes were richer in total free terpenes, and the resulting wines contained greater amounts of volatile compounds. The predominant compounds were free esters, but linalool, rose oxide, citronellol and geraniol can also contribute to wine aroma, particularly for fast dehydration. β-Damascenone can be an active odorant, although its contribution was greater in wines made from slow dehydrated grapes., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

The changes in the volatile composition of Moscato bianco grapes were evaluated during ripening. Grape berries were sampled for five weeks (16-20 °Brix) and sorted for each date in ten density classes (1.05-1.12g/cm(3)). The highest total concentration of free terpenes was found at 19.3 °Brix; however, total concentration of the bound fraction increased significantly throughout ripening. Response surface methodology was used to assess the simultaneous effect of sampling time and berry density on the volatile composition, which was satisfactorily fitted to regression models for some key terpene compounds. Total free and bound terpenes were more affected by grape density than by sampling date. The same behaviour was observed for free and bound linalool and bound nerol, whereas the stronger effect of sampling date was exhibited for bound t-rose oxide, c-rose oxide and geraniol. The results showed that the sampling strategy impacted strongly on the aroma quality of berries., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

This study was focused on the assessment of single and sequential extraction methods to predict the bioavailability of metals in the vineyard soil-grapevine system. The modified BCR sequential extraction method and two single-step extraction methods based on the use of EDTA and acetic acid were applied to differently amended vineyard soils. The variety effect was studied on the uptake of metals by leaves and grapes. Most of the elements studied (Ca, Mg, Cu, Fe, Mn, Zn and Pb) were weakly mobilized from vineyard soils, with the exception of Cu and Mn. The determination of total metal content in leaves and grapes showed a different accumulation pattern in the two parts of the vine. A significant relationship was observed, for all the elements studied except for Fe, between the content bioavailable in the soil and the accumulated in both leaves and grapes (R=0.602-0.775, p<0.01)., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

This study represents the first time that the extraction of phenolic compounds from the seeds is assessed from instrumental texture properties for dehydrated grapes. Nebbiolo winegrapes were postharvest dehydrated at 20°C and 41% relative humidity. During the dehydration process, sampling was performed at 15%, 30%, 45% and 60% weight loss. The extractable fraction and extractability of phenolic compounds from the seeds were determined after simulated maceration. The evolution of mechanical and acoustic attributes of intact seeds was also determined during grape dehydration to evaluate how these changes affected the extraction of phenolic compounds. The extractable content and extractability of monomeric flavanols and proanthocyanidins, as well as the galloylation percentage of flavanols, might be predicted easily and quickly from the mechanical and acoustic properties of intact seeds. This would help in decision-making on the optimal dehydration level of winegrapes and the best management of winemaking of dehydrated grapes., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

The impact of postharvest withering rates on the phenolic composition of 'reinforced' wines produced with partially dehydrated grapes was evaluated. The study was performed on winegrape varieties with anthocyanin profiles differently constituted of di- and tri-substituted forms. Dehydration induced limited changes in the anthocyanin profile of berry skins. Nevertheless, the greatest abundance of total anthocyanins and their more stable forms (malvidin-3-glucoside and acylated glucosides) corresponded to the wines made from slow withered Chatus grapes, which were in turn the darkest. In contrast, the wines made from withered Avanà grapes did not meet good chromatic characteristics due to low contents of total anthocyanins and high ratios between di- and tri-substituted forms. Nebbiolo wines showed intermediate values of this ratio, and therefore of clarity and color intensity. The fast process is recommended because higher percentages of galloylated flavanols in the seeds of slow withered Nebbiolo grapes may have a negative influence on wine astringency., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

The aim of this work was to determine the impact of using independently berry density and diameter as sorting methodologies on important physicochemical parameters affecting the grape quality, such as mechanical properties, phenolic composition and aromatic profile. Muscat Hamburg berries were classified according to the density by flotation in different salt solutions and to the diameter. The three most representative density (1081, 1088 and 1094 kg/m(3)) and diameter (16-17, 18-19 and 20-21 mm) classes were selected. The results showed that there were relationships of both density and diameter with the mechanical properties and chemical composition of the berries. Densimetric sorting is a more promising methodology to separate grape berries with different quality attributes, particularly skin hardness, berry cohesiveness and resilience, total hydroxycinnamic acids, anthocyanins and rose oxide, than diameter sorting. This knowledge can be of great interest for the 'fresh-cut' industry in the production of 'ready-to-eat' fruits salad., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

The evolution of the content and profile of anthocyanins was studied in the skin and pulp of Gamay winegrapes during twelve days of carbonic maceration. The ripening effect was also investigated using berries belonging to two density classes (A=1094-1100 kg/m(3) and B=1107-1115 kg/m(3)). The ripest berries showed a higher extraction yield, even though the differences among density classes tended to decline towards the end of the process, and few significant differences were found in the anthocyanin profile. The maceration time influenced strongly not only the content and extraction yield, but also the qualitative composition of anthocyanins towards the predominance of malvidin derivatives. Finally, the extraction yield of anthocyanins was positively related with the ethanol formed and the skin mechanical properties using linear regression models, which showed that the skin hardness is likely to be an important variable in modelling daily anthocyanin extraction during carbonic maceration, particularly from the sixth day., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

This study was performed to evaluate and compare the effects of different pre-treatments of whole grape berries (freezing with dry ice or in a cold room, steam blanching with different exposure times, and microwave heating with different exposure times and microwave power density) on total content of some phenolic compounds and the composition of individual anthocyanins released into the pulp during the treatment and those extracted during the maceration step. Two red winegrape varieties with different proportions of di- and trisubstituted anthocyanins were used (Nebbiolo and Barbera, respectively). Pulp-extracted anthocyanins were more significantly influenced by the pre-treatment. The results highlighted that freezing with dry ice, followed by freezing in a cold room and steam blanching for 5 min, have a great potential from an industrial point of view. They facilitated the extraction of anthocyanins in the must prior to maceration, when compared with the control samples, increasing their total content (+37.8-83.6%), and modifying the anthocyanin profile through the enrichment in the most stable compounds (+2.8-6.6% malvidin derivatives) to the detriment of others more prone to oxidation (-0.8-11.0% cyanidin derivatives). In Nebbiolo winegrapes, an improved extraction of low- and high-molecular weight flavanols into the pulp was also observed (+60.4-73.4%). Significant relationships between the phenolic composition of treated berries and the corresponding skin mechanical properties were also studied, but they were variety dependent. Discriminant analysis permitted a correct classification of the samples according to the variety and pre-treatment.

The feasibility of Fourier transform-near-infrared (FT-NIR) spectroscopy for predicting the extractable content of phenolic compounds directly in intact grape seeds was evaluated. NIR calibration models were based on the correlation of spectral data with the phenolic composition determined by reference chemical methods for 40 grape samples. The vintage effect was studied evidencing that the predictive accuracy improved only for spectrophotometric indices when samples of two years were simultaneously considered. The statistical parameters of calibration showed that the models developed are sufficiently robust for quantitative purposes of total flavonoids, proanthocyanidins, low molecular weight flavanols, catechin, epicatechin, procyanidin B1, and galloylation percentage (standard prediction error (SEP%) < 15, predictive index (RPIQ) > 3.0), but could be also useful for screening of absorbance at 280 nm, total polymers, epicatechin gallate, and procyanidin B2 (SEP% < 15, RPIQ = 2.7-2.9). Although a calibration model is required for each geographical origin, the results suggest that FT-NIR spectroscopy is a promising analytical technique in this field.

The use of instrumental acoustic parameters produced during a compression test as reliable predictors of the extractable phenolic composition in intact winegrape seeds, determined by reference chemical methods, was evaluated by means of the analytical performance of calibration models. These models were developed only for those phenolic compounds most significantly and strongly correlated with the acoustic parameters. The analytical performance of the models was expressed in terms of standard error of cross-validation (SECV) and residual predictive interquartile amplitude (RPIQ), among other statistics. Several acoustic parameters showed satisfactory predictive accuracy for the percentage of galloylation in the terminal units, the content of (-)-epicatechin, and the mean degree of polymerization. Most of the reliable models developed are fairly recommended not for quantitative purposes but for fast screening (SECV% < 19, 1.6 < RPIQ < 2.1).

In the oenological sector, the withering process is of particular importance in the production of dry and sweet dessert wines due to the total or partial use of overripe and/or dehydrated grapes. This complex process leads to several changes in the chemical-physical characteristics of white grape berries affecting the wine quality and, at the end of the dehydration period, different visual attributes are usually present in the berry skins. The aim of this work, therefore, was to study the properties of Erbaluce dried grapes of varying external colors, classified into three groups based on reflectance colorimetry (green, gold and blue). The chemical composition, volatile profile and mechanical attributes were investigated, focusing on establishing relationships between CIEL*a*b* parameters of dehydrated grapes and their chemical-physical characteristics. The higher values of the glucose-fructose ratio, together with the higher content of sugars, gluconic acid and glycerol, but lower titratable acidity, suggests the presence of Botrytis cinerea Pers. infection in blue withered berries, which has been microbiologically confirmed. Regarding the instrumental mechanical properties, blue dehydrated grapes were characterized by a lower skin hardness and higher skin thickness in agreement with the higher weight loss experienced. Finally, the determination of free and bound volatile compounds showed that some of them were only found in blue withered berries, δ-lactones being considered the main chemical markers of the noble rot infection that are important for the odor character. C-10 alkyl massoia lactone was the most abundant volatile compound in blue botrytized grapes., (Copyright © 2011 Elsevier B.V. All rights reserved.)

The main aims of this work were to classify 30 colored and white wine grape varieties according to the berry skin hardness, to assess the influence of annual variations in climate on the berry skin hardness, and to establish significant relationships among berry skin mechanical properties and some climatic-bioclimatic indices calculated for different grape-ripening periods, close to the harvest date. The results obtained show that the most influential bioclimatic indices on the skin mechanical attributes were temperature parameters. In the same season, the influence of the production area was also evaluated, precipitation parameters being the best correlated with the berry skin hardness. This first work has permitted us to know the relationship among skin texture characteristics and seasonal climatic indices.

Background: Knowledge of the influence of initial mechanical properties on the evolution of the weight loss of berries through the drying process is scarce. Therefore, the main purpose of this work was to investigate the effect of skin hardness at two different physiological stages of off-vine drying kinetics of grapes. Skin hardness was evaluated as the berry skin-break force parameter, measured by the texture analysis test., Results: The decrease of berry weight as a function of the drying time was linear, indicating that the drying rates were constant within each cultivar studied (Moscato bianco and Erbaluce), and for each ripening stage and berry skin hardness. The drying rates decreased as berry skin hardness increased for the ripest grapes in the cultivars studied., Conclusion: The study allowed the assessment of the correlation between the skin hardness of fresh berries and the weight loss determined for different drying days., (2010 Society of Chemical Industry.)