Copper (II) Level in Musts Affects Acetaldehyde Concentration, Phenolic Composition, and Chromatic Characteristics of Red and White Wines.

Copper (II), a vital fungicide in organic viticulture, also acts as a wine oxidation catalyst. However, limited data are currently available on the impact that maximum allowed copper (II) ion doses in wine grapes at harvest can have on aged wine quality. This was the focus of the present study. We investigated the copper (II) effects by producing both white and red wines from musts containing three initial metal concentrations according to the limits set for organic farming. In detail, the influence of copper (II) on fermentation evolution, chromatic characteristics, and phenolic compounds was evaluated. Interestingly, the white wine obtained with the highest permitted copper (II) dose initially exceeded the concentration of 1.0 mg/L at fermentation completion. However, after one year of storage, the copper (II) content fell below 0.2 ± 0.01 mg/L. Conversely, red wines showed copper (II) levels below 1.0 mg/L at the end of fermentation, but the initial copper (II) level in musts significantly affected total native anthocyanins, color intensity, hue, and acetaldehyde concentration. After 12-month aging, significant differences were observed in polymeric pigments, thus suggesting a potential long-term effect of copper (II) on red wine color stability.

Multivariate prediction of Saliva Precipitation Index for relating selected chemical parameters of red wines to the sensory perception of astringency.

Astringency is an essential sensory attribute of red wine closely related to the saliva precipitation upon contact with the wine. In this study a data matrix of 52 physico-chemical parameters was used to predict the Saliva Precipitation Index (SPI) in 110 Italian mono-varietal red wines using partial least squares regression (PLSr) with variable selection by Variable Importance for Projection (VIP) and the significance of regression coefficients. The final PLSr model, evaluated using a test data set, had 3 components and yielded an R2test of 0.630 and an RMSEtest of 0.994, with 19 independent variables whose regression coefficients were all significant at p < 0.05. Variables selected in the final model according to the decreasing magnitude of their absolute regression coefficient include the following: Procyanidin B1, Epicatechin terminal unit, Total aldehydes, Protein content, Vanillin assay, 520 nm, Polysaccharide content, Epigallocatechin PHL, Tartaric acid, Volatile acidity, Titratable acidity, Catechin terminal unit, Proanthocyanidin assay, pH, Tannin-Fe/Anthocyanin, Buffer capacity, Epigallocatechin PHL gallate, Catechin + epicatechin PHL, and Tannin-Fe. These results can be used to better understand the physico-chemical relationship underlying astringency in red wine.

Nitrogen maceration of wine grape: An alternative and sustainable technique to carbonic maceration.

Carbonic maceration (CM) consists in placing intact grape bunches into a sealed tank to have a natural or artificially created carbon dioxide atmosphere. No articles have been published on the comparison between CM and nitrogen maceration (NM). Therefore, the present study aimed at testing the use of alternative maceration technique (NM) in alternative to CM, to create the conditions of anoxia on the Gamay variety. The results showed a higher concentration of polyphenols and anthocyanins in the macerated wines, especially in NM wine. Concerning VOCs (Volatile Organic Compounds), the CM wine showed the highest content in esters while the total alcohol content was slightly higher in the NM wines. The CM wine had the highest content in volatile medium chain fatty acids (MCFA). E-nose measurements revealed a clear separation among the samples, and the E-nose data, in PCA computation, were generally overlapped by the PCA of VOCs analysis. The NM showed a potential as environmentally sustainable technique useful to produce a new style of macerated and aromatic wines.

The Management of Dissolved Oxygen by a Polypropylene Hollow Fiber Membrane Contactor Affects Wine Aging.

BACKGROUND: Numerous oenological practices can cause an excess of dissolved oxygen in wine, thus determining sensory and chromatic defects in the short- to long-term. Hence, it is necessary to manage the excess of oxygen before bottling. METHODS: In this study, the management of the dissolved oxygen content by a polypropylene hollow fiber membrane contactor apparatus was performed in two wines from different grape varieties (Aglianico and Falanghina). The wines were analyzed after an 11-month aging. Anthocyanins and acetaldehyde content were evaluated by HPLC. In addition, other phenolic compounds and chromatic characteristics were analyzed by spectrophotometric methods. NMR and HR ESIMS analyses were conducted to evaluate the amount of pyranoanthocyanins and polymeric pigments. RESULTS: After 11 months of aging, in both wines a decrease of free and total SO2 with respect to initial values was detected. In the wines with the highest dissolved oxygen levels, a more remarkable loss was observed. No significant differences in terms of color parameters were detected. In red wine with the highest oxygen content, a massive formation of polymeric pigments and BSA reactive tannins was observed, as opposed to wines with lower oxygen levels. CONCLUSION: The study demonstrated that the membrane contactor can prove a successful tool to manage dissolved oxygen in wines as to prevent their oxidative spoilage.

Phenolic Profiles of Red Wine Relate to Vascular Endothelial Benefits Mediated by SIRT1 and SIRT6.

Dietary phenolic compounds possess potent bioactivity against inflammatory pathways of chronic inflammatory conditions, such as type 2 diabetes. Here, the phenolic profile and bioactivity of Italian red wines Gaglioppo, Magliocco, and Nerello Mascalese were characterized. NMR, HPLC/UV-Vis and spectrophotometric characterization showed that Magliocco was the richest wine in monomeric anthocyanins (two-fold), catechins, and low molecular weight phenolics (LMWP). A positive correlation was observed between the polyphenolic content and antioxidant capacity (p < 0.05), with Magliocco displaying the highest antioxidant capacity (p < 0.01). In vitro evidence on the endothelial cell models of insulin resistance and hyperglycemia showed the ability of Magliocco to reduce reactive oxygen species (ROS) (p < 0.01) and cytokine release (p < 0.01) and to upregulate SIRT1 and SIRT6 (p < 0.01). On the whole, the results indicated that the quantitative and qualitative phenolic profiles of red wines influence their in vitro beneficial effects on oxidative and proinflammatory milieu in endothelial cells, showing a positive modulation of SIRT1 and SIRT6, both implied in vascular aging.

Minty aroma compounds in red wine: Development of a novel automated HS-SPME-arrow and gas chromatography-tandem mass spectrometry quantification method.

A novel automated method was developed for the quantitative determination of nine terpenoids that could contribute to the minty notes of red wine bouquet. The method couples headspace SPME-Arrow extraction with GC-MS/MS analysis. PDMS/DVB fiber was chosen for the extraction and an ionization energy of 30 eV permitted to optimize the analyte detection. The optimal sample preparation consists of a two-fold dilution of the wine sample with addition of 4 g of sodium chloride while the most suitable extraction conditions take place at 50 °C for 1 h. The method shows good linearity, intraday variations between 2 and 25%, interday variations between 7 and 23% and recoveries between 80 and 119%. The method exhibits the required low detection (between 3 and 60 ng/L) and quantification (between 6 ng/L and 200 ng/L) limits. These limits have permitted the quantification of the pool of minty terpenoids in fourteen red Bordeaux wines.

Exploring Olfactory-Oral Cross-Modal Interactions through Sensory and Chemical Characteristics of Italian Red Wines.

This work aimed at investigating red wine olfactory-oral cross-modal interactions, and at testing their impact on the correlations between sensory and chemical variables. Seventy-four Italian red whole wines (WWs) from 10 varieties, and corresponding deodorized wines (DWs), were evaluated by sensory descriptive assessment. Total phenols, proanthocyanidins, ethanol, reducing sugars, pH, titratable and volatile acidity were determined. PCA results highlighted different sensory features of the 10 wine types. ANOVAs (p < 0.05) showed that olfactory cues might play modulation effects on the perception of in-mouth sensations with 7 (harsh, unripe, dynamic, complex, surface smoothness, sweet, and bitter) out of 10 oral descriptors significantly affected by odours. Three weak but significant positive correlations (Pearson, p < 0.0001) were statistically found and supported in a cognitive dimension: spicy and complex; dehydrated fruits and drying; vegetal and unripe. In the absence of volatiles, correlation coefficients between sensory and chemical parameters mostly increased. Proanthocyanidins correlated well with drying and dynamic astringency, showing highest coefficients (r > 0.7) in absence of olfactory-oral interactions. Unripe astringency did not correlate with polyphenols supporting the idea that this sub-quality is a multisensory feeling greatly impacted by odorants. Results support the significance of cross-modal interactions during red wine tasting, confirming previous findings and adding new insights on astringency sub-qualities and their predictive parameters.

NMR-based systematic analysis of bioactive phytochemicals in red wine. First determination of xanthurenic and oleanic acids.

Experimental evidence suggests that moderate consumption of wine has health promoting properties that have been mainly attributed to the wine polyphenol content. However, a systematic analysis of the major healthy molecules contained in wines has not been conducted yet. Our study explored the potential arsenal of beneficial molecules contained in wine from both a qualitative and quantitative perspective. The experimental approach was based on chromatography and untargeted NMR spectroscopy. In addition to already known bioactive molecules, for the first time, xanthurenic acid and oleanic acid were identified in wine in relatively high concentrations. On account of their many biological activities, these two molecules widen the range of potential beneficial effects of wine and pave the way toward the evaluation of their still unexplored sensory properties.

NMR-based phytochemical analysis of Vitis vinifera cv Falanghina leaves. Characterization of a previously undescribed biflavonoid with antiproliferative activity.

Vitis vinifera cv Falanghina is an ancient grape variety of Southern Italy. A thorough phytochemical analysis of the Falanghina leaves was conducted to investigate its specialised metabolite content. Along with already known molecules, such as caftaric acid, quercetin-3-O-ß-d-glucopyranoside, quercetin-3-O-ß-d-glucuronide, kaempferol-3-O-ß-d-glucopyranoside and kaempferol-3-O-ß-d-glucuronide, a previously undescribed biflavonoid was identified. For this last compound, a moderate bioactivity against metastatic melanoma cells proliferation was discovered. This datum can be of some interest to researchers studying human melanoma. The high content in antioxidant glycosylated flavonoids supports the exploitation of grape vine leaves as an inexpensive source of natural products for the food industry and for both pharmaceutical and nutraceutical companies. Additionally, this study offers important insights into the plant physiology, thus prompting possible technological researches of genetic selection based on the vine adaptation to specific pedo-climatic environments.

Evaluation of the use of sulfur dioxide and glutathione to prevent oxidative degradation of malvidin-3-monoglucoside by hydrogen peroxide in the model solution and real wine.

In this study the oxidative degradation by hydrogen peroxide of native grape anthocyanin was studied in model solutions and in red wines added with increasing concentration of sulfur dioxide and glutathione (GSH). The presence of hydrogen peroxide and metal ions in traces allowed to investigate the possibility to use GSH to prevent Fenton reaction in wine conditions. Two different pH of wine were considered: 3.20 and 3.80. The protective effect of sulfur dioxide on malvidin 3-monoglucoside degradation was higher at lower pH in model solution. No effect of pH on sulfur dioxide action towards the native anthocyanin in real wine was detected. Surprisingly GSH determined an increase in the degradation of malvidin 3-monoglucoside regardless of pH. Therefore, GSH is not effective in prevent native anthocyanins loss due to the Fenton reaction during red wine aging.

Metabolic and RNA profiling elucidates proanthocyanidins accumulation in Aglianico grape.

Aglianico grapes are known for their high content of proanthocyanidins (PAs), which are responsible for the astringency of wines derived from this cultivar. However, the accumulation of PAs and their genetic control during berry development remain largely unexplored. This work aimed to monitor astringency-causing PAs in Aglianico berries and correlate them with the expression of 14 key genes. Berries were collected during ripening and dissected in skins and seeds. PAs were fractionated and the content of total phenolics, flavans, anthocyanins, tannins reactive towards salivary proteins and tannin structural composition were evaluated. The results provided evidence that PAs were more abundant in seeds than in skins as expected, with differences in the structural composition between tissues, which did not varied during ripening. Expression analysis showed that Aglianico is able to accumulate polyphenols due to its ability to modulate key genes in a tissue-specific manner.

Chip electrophoresis as a novel approach to measure the polyphenols reactivity toward human saliva.

Saliva is a biological fluid with a multifunctional role that makes it interesting in terms of research and diagnostic possibilities. In food research, human saliva represented a useful tool by which we measure the tactile sensation elicited by polyphenol-rich beverages called astringency. A method based on SDS-PAGE analysis of saliva before and after the binding reaction with wine polyphenols has been successfully used in previous studies for measuring wine astringency by means of the saliva precipitation index. In this work, chip electrophoresis was used alternatively to SDS-PAGE and results were compared. Chip electrophoresis provides a very good reproducibility for wine and grape astringency. Moreover, this approach is much faster than the conventional SDS-PAGE method requiring several hours for an analysis. Another advantage over traditional gel is lower sample and reagent volume requirements, as well as the lower and less toxic wastes, contributing benefits to health and environment. The application of this novel method allowed, using the principal component analysis, to distinguish grapes and wines according to the saliva precipitation index and structural characteristics determined by the phoroglucinolysis analysis.

Biochemical features of native red wines and genetic diversity of the corresponding grape varieties from Campania region.

Campania region has always been considered one of the most appreciated Italian districts for wine production. Wine distinctiveness arises from their native grapevines. To better define the chemical profile of Campania autochthonous red grape varieties, we analysed the phenolic composition of Aglianico di Taurasi, Aglianico del Vulture, Aglianico del Taburno, Piedirosso wines, and a minor native variety, Lingua di Femmina in comparison with Merlot and Cabernet Sauvignon, as reference cultivars. A genetic profiling was also carried out using microsatellite molecular markers with high polymorphic and unambiguous profiles. Principal component analysis applied to 72 wines based on the 18 biochemical parameters, explained 77.6% of the total variance and highlighted important biological entities providing insightful patterns. Moreover, comparison of SSR-based data with phenylpropanoid molecules exhibited a statistically significant correlation. Our approach might be reasonably adopted for future characterisations and traceability of grapevines and corresponding wines.

Application of the SPI (Saliva Precipitation Index) to the evaluation of red wine astringency.

The aim of this work was to evaluate the astringency of red wines by means of a SDS-PAGE based-method. The optimization of the in vitro assay, named SPI (Saliva Precipitation Index) that measured the reactivity of salivary proteins towards wine polyphenols, has been performed. Improvements included the choice of saliva:wine ratio, saliva typology (resting or stimulated saliva), and temperature of binding. The LOD (0.05 g/L of condensed tannin) and LOQ (0.1g/L of condensed tannin) for the binding reaction between salivary proteins and tannins added in white wine were also determined. Fifty-seven red wines were analysed by the optimised SPI, the Folin-Ciocalteu Index, the gelatine index, the content of total tannins and the sensory quantitative evaluation of astringency. A significant correlation between the SPI and the astringency of red wines was found (R(2)=0.969), thus indicating that this assay may be useful as estimator of astringency.

Precipitation of salivary proteins after the interaction with wine: the effect of ethanol, pH, fructose, and mannoproteins.

UNLABELLED: Astringency is a complex sensation mainly caused by the precipitation of salivary proteins with polyphenols. In wine it can be enhanced or reduced depending on the composition of the medium. In order to investigate the effect of ethanol, tartaric acid, fructose, and commercial mannoproteins (MPs) addition on the precipitation of salivary proteins, the saliva precipitation index (SPI) was determined by means of the sodium dodecyl sulphate polyacrylamide gel electrophoresis of human saliva after the reaction with Merlot wines and model solutions. Gelatin index, ethanol index, and Folin-Ciocalteu index were also determined. As resulted by Pearson's correlation, data on SPI were well correlated with the sensory analysis performed on the same samples. In a second experiment, increasing the ethanol (11%-13%-17%), MPs (0-2-8 g/L), fructose (0-2-6 g/L) level, and pH values (2.9-3.0-3.6), a decrease in the precipitation of salivary proteins was observed. A difference in the SPI between model solution and red wine stated that an influence of wine matrix on the precipitation of salivary proteins occurred. PRACTICAL APPLICATION: Results provide interesting suggestions for enologists, which could modulate the astringency of red wine by: (i) leaving some residual reducing sugars (such as fructose) in red wine during winemaking of grapes rich in tannins; (ii) avoiding the lowering of pH; (iii) adding commercial mannoproteins or promoting a "sur lie" aging; and (iv) harvesting grapes at high technological maturity in order to obtain wines with a satisfactory alcoholic content when possible.

Aroma composition of red wines by different extraction methods and Gas Chromatography-SIM/MASS spectrometry analysis.

One hundred and one volatile compounds, reported in literature as powerful odorants of wine, were quantified by Gas Chromatography-Selective Ion Monitoring/Mass Spectrometry (GC-SIM/MS) in Primitivo, Aglianico, Merlot and Cabernet Sauvignon red wines. Wine samples were extracted by 3 different extraction methods: 1) separation of the alcoholic fraction from the aqueous phase by salting-out and subsequent extraction by liquid-liquid micro-extraction with 1,1,2-trichlorotrifluoroethane (Freon 113); 2) extraction by liquid-liquid micro-extraction with dichloromethane; 3) solid phase extraction (SPE cartridge: 800 mg of LiChrolut EN resin) with pentane-dichloromethane (20:1) and dichloromethane. The selection of the ion fragments used for quantification was directly performed on a red wine sample. For each compound the area of the corresponding peak was normalized respect to the peak of the internal standard and then interpolated in a calibration curve obtained analysing a model wine solution (water, ethanol, tartaric acid and known amounts of analytes and of internal standard). The methods showed a good linearity: r2>0.990, except for farnesol (isomer a and c), octanal, decanal, furaneol and phenylacetic acid with 0.966 < or = r2 < or = 0.990. The 7 most powerful odorants were: beta-damascenone, acetaldehyde, maltol, ethyl 2-methylbutanoate, ethyl 3-methylbutanoate, 3-methylbutanoic acid and acetal; 7 other slightly less important were: ethyl hexanoate, ethyl acetate, 1-octen-3-ol, butanoic acid, rose oxide, furaneol and sotolon. The Aglianico wines were characterised by the major fermentation compounds (esters, fatty acids and 2-phenylethanol), beta-damascenone, beta-ionone and linalool. The Primitivo wines were characterized by furaneol, methoxypyrazine, gamma-nonalactone and acetaldehyde, while Cabernet Sauvignon and Merlot wines principally by cask derivates (vanillin, (Z) 3-methyl-gamma-octalactone [(Z) wiskylactone], maltol and eugenol), some aldehydes and 3-isopropyl-2-methoxypyrazine.

Determination of furaneol (4-hydroxy-2,5-dimethyl-3(2H)-furanone) in some wines from Italian native grapes by Gas-Chromatography-SIM/MASS spectrometry.

Gas Chromatography-Mass Spectrometry (GC-MS) analysis by Selective Ion Monitoring (SIM) was applied to quantify 4-Hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF) in both red and white wines obtained from some Italian cultivar of Vitis vinifera. Wines were extracted by liquid-liquid extraction performed with 1,1,2-trichlorotrifluoroethane (Freon 113). The ion m/z 128 was used for quantification while the ion m/z 129 as qualifier. Precision, linearity and accuracy of the method resulted satisfactory. Results showed a significant variation in the concentration of furaneol in wine with grape variety. Generally, HDMF concentrations in white wines were lower than in red wines. Among white wines, Chardonnay resulted characterized by the highest concentration of HDMF. Among red wines the highest concentrations of HDMF were detected in Primitivo and Refosco varieties.

Effect of antioxidant protection of must on volatile compounds and aroma shelf life of Falanghina (Vitis vinifera L.) wine.

Two vinification methods involving different degrees of antioxidant protection of Falanghina must during prefermentative steps, and referred as HAMP (high antioxidant must protection) and LAMP (low antioxidant must protection), were compared in terms of fermentation performances of four different yeast strains, composition of the volatile fraction of wines at the end of alcoholic fermentation, and shelf life of wines during storage. The use of HAMP technology resulted in wines with lower volatile acidity and higher concentrations of medium-chain fatty acid ethyl esters, acetates, and volatile fatty acids. For two of the four strains a lower concentration of isoamyl alcohol was also observed. HAMP wines also revealed increased shelf life because of the higher concentration of odor active esters at the end of storage and better preservation of varietal aromas.