Interactions between polyphenols and volatile compounds in wine: A literature review on physicochemical and sensory insights

Wine polyphenols (PPhs) and volatile organic compounds (VOCs) are responsible for two of the main sensory characteristics in defining the complexity and quality of red wines: astringency and aroma. Wine VOCs’ volatility and solubility are strongly influenced by the matrix composition, including the interactions with PPhs. To date, these interactions have not been deeply studied, although the topic is of great interest in oenology. This article reviews the available knowledge on the main physicochemical and sensory effects of polyphenols on the release and perception of wine aromas in orthonasal and retronasal conditions. It describes the molecular insights and the phenomena that can modify VOCs behavior, according to the different chemical classes. It in-troduces the possible impact of saliva on aroma release and perception through the modulation of polyphenols–aroma compounds interactions. Limitations and possible gaps to overcome are presented together with updated approaches used to investigate those interactions and their effects, as well as future perspectives on the subject

Extraction of phenolic compounds from 'Aglianico' and 'Uva di Troia' grape skins and seeds in model solutions: Influence of ethanol and maceration time

The effect of increasing concentration of ethanol (0, 4, 7.5 and 13 %) and contact time (respectively 1, 4, 7 and 10 days) on the extraction of phenolics from berry skins and seeds of the grape, Vitis vinifera 'Aglianico' and 'Uva di Troia', were examined. Two assays of post-fermentative maceration in two hydroalcoholic solutions at 11 and 13 % ethanol, were also performed. Chromatic properties and phenolics of medium were analyzed by HPLC and spectrophotometric methods. The extraction of total phenolics, anthocyanins, proanthocyanidins, and vanilline reactive flavans (VRF) from berry skins reached the maximum on the 4th day of maceration. Quercetin and gallic acid were gradually extracted from grape skins. The maximum release of flavan-3-ols from the skins was achieved on the first day of maceration. Total phenolics, tannins and VRF were gradually extracted from seeds. During the postfermentative maceration, higher the content of ethanol, higher the extraction of total polyphenols and tannins from 'Uva di Troia' skins and the extraction of total polyphenols and tannins from 'Aglianico' seeds. These results clearly indicate that the grape cultivar mainly influences the release of phenolic compounds from the solid parts of berry to the must especially during postfermentative maceration.

Free and glycosylated green leaf volatiles, lipoxygenase and alcohol dehydrogenase in defoliated Nebbiolo grapes during postharvest dehydration

none7noBackground and Aims: Nebbiolo grapes are used to produce Sfursat wine, following partial dehydration. This research aimed to clarify the influence of fruit exposure to light and postharvest water loss on the concentration of green leaf volatiles (GLVs) and lipoxygenase (LOX) and alcohol dehydrogenase (ADH) activity of grapes. Methods and Results: Nebbiolo grapes from Control vines (no defoliation) (ND) and from vines defoliated at fruitset (DFS) or defoliated post-veraison (DPV) were harvested at about 23°Brix and dehydrated at 10 and 20°C, 60% RH and air flow of 1.5 m/s. Berries were sampled at 10 and 20% mass loss (ML). Significant differences in crop yield, bunch mass and berry mass were observed. As expected, the higher the dehydration temperature, the faster the dehydration process: 20% ML at 20°C occurred between 18 and 25 days, the shortest time corresponding to ND and the longest to DFS; at 10°C, the dehydration lasted between 27 and 32 days. At 10°C, the ADH activity was almost double that at 20°C, and in DFS was much higher than in other samples. At harvest, LOX did not show any difference among the samples, while at 10°C and 10% ML, the enzyme activity increased significantly and then declined at 20% ML, especially in defoliated samples. At harvest, the total free GLVs associated with the metabolism of lipid oxidation were 9434, 7212 and 11 656 μg/kg dry weight (DW) in ND, DFS and DPV samples, respectively; the total bound GLVs lipid-derived were 7599, 18 486 and 15 409 μg/kg DW in ND, DFS and DPV samples, respectively. During dehydration at 10°C, the ML induced ADH + LOX activity, especially in defoliated samples, but the bound GLVs, produced by defoliation, greatly decreased. Conclusions: Defoliation affected the response of Nebbiolo grapes to dehydration temperature: postharvest cold stress (10°C) and ML induced glycosylation of GLVs, alcohol formation (via ADH) and membrane oxidation (via LOX); a further stress effect was observed with leaf removal, regardless of the time of application. Significance of the Study: The timing of defoliation and postharvest dehydration temperature are significant factors to mitigate the postharvest stress response of Nebbiolo grapes.openPiombino P.; Genovese A.; Rustioni L.; Moio L.; Failla O.; Bellincontro A.; Mencarelli F.Piombino, P.; Genovese, A.; Rustioni, L.; Moio, L.; Failla, O.; Bellincontro, A.; Mencarelli, F

Free and Enzymatically Hydrolysed Volatile Compounds of Sweet Wines from Malvasia and Muscat Grapes (Vitis vinifera L.) Grown in Sardinia

The aroma of Muscat of Sorso-Sennori and Malvasia di Bosa wines obtained from grapes grown in Sardinia wasevaluated by instrumental analysis. Gas chromatography/mass spectrometry was used to identify and quantifythe content of free and bound volatile compounds. The odour activity value (OAV) was also calculated. Higheralcohols and esters were quantitatively the largest group of free volatile compounds in both wines, while terpeneswere the main class of bound volatiles. A total of 52 free and 26 bound volatiles were detected. Malvasia di Bosasweet wine had a higher content of alcohols, esters and acids in comparison to Muscat of Sorso-Sennori, whichwas richer in some terpenes, like nerol, geraniol and geranic acid, and also in bound volatile compounds. Atotal of 12 compounds were above the OAV. The main aroma-active compounds of Muscat were 3-methylbutylacetate (banana), ethyl octanoate and hexanoate (fruity), and linalool (flowery), Malvasia wine was characterisedparticularly by ethyl octanoate and by 3-methylbutyl acetate

Effect of Bottle Storage on Colour, Phenolics and Volatile Composition of Malvasia and Moscato White Wines

The effect of bottle storage on the colour, phenolics and volatile composition of Malvasia and Muscat winesobtained from grapes grown in Sardinia was evaluated. Colour was evaluated by UV-VIS spectrophotometryand by tristimulus colorimetry. Polyphenols were analysed by UV-VIS spectrophotometry and HPLCDAD.GC/MS was used to identify and quantify the content of free and bound volatile compounds. Asexpected, the absorbance values at 420 nm increased significantly for both wines during storage, due tooxidative browning, while difference in colour (DE*) from the beginning of storage and after 18 monthswas more intense in the Muscat wine than in the Malvasia wine. A significant decrease was observed indifferent phenolic compounds over time, especially in the Malvasia wine. In-bottle storage for 18 monthsat 20°C in the dark resulted in a significant decrease in all the classes of free and bound volatiles. Thesefinding enhance knowledge regarding the effects of bottle storage on Muscat and Malvasia wines. Thisis of interest because, rather surprisingly, this topic has been poorly investigated in relation to these twovarieties

Terpenoids and norisoprenoids in Italian red wines

AIM Terpene compounds are associated with fl oral notes and are characteristic of aromatic grape varieties such as Muscat (Jackson,2008). They are generally considered to potentially contribute to the aroma of white wines. However, there is a growing interesttowards the potential contribution of terpene compounds to the aroma of red wines. The aim of this work was to investigate theoccurrence of diff erent terpenes in red wines from Italian varieties. METHODS For this study wines from 11 mono-varietal Italian redwines from 12 regions were used (19 Sangiovese, 11 Nebbiolo, 10 Aglianico, 11 Primitivo, 10 Raboso del Piave, 9 Cannonau, 11 Teroldego,3 Nerello, 9 Montepulciano, 7 Corvina). All samples were from vintage 2016 and none of them had been in contact with wood. A totalof 19 terpenes and 7 norisoprenoids were analysed by mean of SPME-GC-MS analysis using a DVB-CAR-PDMS fi ber. The wines werecollected in the framework of the activities of the D-Wines (Diversity of Italian wines) project. RESULTS Signifi cant diff erences amongvarieties were observed for basically all the compounds analyzed with the exception of limonene. Overall, the concentrations of thevarious terpenes remained in the same order of magnitude. However, some diff erences are noticeable between varieties. Corvina wascharacterized by higher level of linalool, followed by Aglianico, Nebbiolo, Primitivo and Sangiovese. Cyclic terpenoids appeared asgood varietal markers, for instances Montepulciano was characterized by 1,4-cineole and 1,8-cineole, whereas Sangiovese showedhigher levels of p-cymene, \u3b1-terpinene and 1,4-cineole. Higher terpinene-1-ol content was characteristic of Montepulciano and Rabosowines. Relatively high levels of the norisoprenoid \u3b2-damascenone were found in Cannonau up to 3.68 \u3bcg/L. CONCLUSIONS This studyprovide the fi rst survey of a large number of terpenoids and norisoprenoids in diff erent mono-varietal Italian red wines. The resultsshowed that a large number of terpenoids were present in Italian red wines with specifi c profi les related to the varieties