Soil effect on proanthocyanidins composition of red and white wines obtained from Nero d'Avola and Grillo Vitis vinifera L. Cultivars

In this study, the effects of the main soil chemical-physical parameters (i.e. texture, pH, total carbonates, cation exchange capacity, electric conductivity, organic matter and mineral endowment) on proanthocyanidin composition of Nero d'Avola red wines and Grillo white wines were investigated. Monomer proanthocyanidins (i.e. (+)-catechin and (-)-epicatechin) and oligomer proanthocyanidins (i.e. B1, B2, B3 and B4 dimers and C1 trimer), as well as proanthocyanidins subunit composition, percentage of galloylation, percentage of prodelphinidins and mean degree of polymerization, were studied for each wine. Results highlighted that the proanthocyanidins composition of both red and white wines is greatly affected by soil. In particular, the proanthocyanidins composition of Nero d'Avola red wines appeared to be affected by the soil physical-chemical parameters related to nutrients dynamics (CEC, EC, pH, organic matter, mineral endowment), whereas the proanthocyanidins composition of Grillo white wines was mainly influenced by the soil texture, that modulates soil water dynamics.

Validation of a routine HPLC method for added fumaric acid determination in wines

Nowadays, grape berries mature earlier due to climate change. Higher sugar contents are observed, whereas lower ones in organic acids, leading to increased pH values. Those biochemical changes have direct consequences on the balance and quality of wines made from such grapes. Chemical acidification, commonly used to compensate for the lack of acidity in musts or wines, includes tartaric, malic, lactic, and citric acids. Fumaric acid (FA), naturally present in the grape berries at low concentrations and already authorized in the member states of the OIV to inhibit malolactic fermentation in wines, seems to be a promising alternative to those acids to lower the pH. However, the evolution of FA levels added at bottling and its impact on wine quality during its conservation have not yet been studied. Therefore, the aim of the present study was to develop and validate a simple method using liquid chromatography coupled with a diode array detector, which can be used routinely for the determination of the added fumaric acid in wines. The proposed and validated method uses a ProntoSIL C-18 analytical column and an isocratic elution with water acidified at 0.1% formic acid. The run time, including column cleaning with acetonitrile and re-equilibration, was 40 minutes.

Oxyresveratrol and Gnetol Glucuronide Metabolites: Chemical Production, Structural Identification, Metabolism by Human and Rat Liver Fractions, and In Vitro Anti-inflammatory Properties

Stilbene metabolites are attracting great interest because many of them exhibit similar or even stronger biological effects than their parent compounds. Furthermore, the metabolized forms are predominant in biological fluids; therefore, their study is highly relevant. After hemisynthesis production, isolation, and structural elucidation, three glucuronide metabolites for oxyresveratrol (ORV) were formed: trans-ORV-4'-O-glucuronide, trans-ORV-3-O-glucuronide, and trans-ORV-2'-O-glucuronide. In addition, two glucuronide metabolites were obtained for gnetol (GN): trans-GN-2'-O-glucuronide and trans-GN-3-O-glucuronide. When the metabolism of ORV and GN is studied in vitro by human and rat hepatic enzymes, four of the five hemisynthesized compounds were identified and quantified. Human enzymes glucuronidated preferably at the C-2' position, whereas rat enzymes do so at the C-3 position. In view of these kinetic findings, rat enzymes have a stronger metabolic capacity than human enzymes. Finally, ORV, GN, and their glucuronide metabolites (mainly at the C-3 position) decreased nitric oxide, reactive oxygen species, interleukin 1β, and tumor necrosis factor α production in lipopolysaccharide-stimulated macrophages.

Evolution of the Crown Procyanidins’ Tetramer during Winemaking and Aging of Red Wine

Condensed tannins play a major role in the quality of red wine. After grape extraction, they quickly evolve thanks to different oxidation mechanisms. Recently, NMR identified a new sub class of condensed tannins, named crown procyanidins, in red wine. The crown procyanidins’ tetramer exhibits a macrocyclic structure composed of four (-)-epicatechin with an unusual cavity in the center of the molecule. These new tannins exposed a higher polarity than the linear tannins. In this work, the evolution kinetics of these crown procyanidins during the winemaking process and after aging of red wine in bottles were studied. Samples’ quantification was analyzed by UPLC-UV-Q-TOF. The concentration of cyclic and non-cyclic procyanidins was compared. During the winemaking process, crown procyanidins are mainly extracted at the beginning of the alcoholic fermentation and they remain stable until the end of the winemaking process. The high polarity and solubility of this new molecule in water was confirmed. During the aging of red wine in bottles, crown procyanidins’ concentrations are stable, whereas the non-cyclic tannins decrease dramatically. Finally, a strong oxygenation experiment confirmed the crown procyanidins’ resistance to oxidation and unique skills.

Trans-ε-Viniferin Encapsulation in Multi-Lamellar Liposomes: Consequences on Pharmacokinetic Parameters, Biodistribution and Glucuronide Formation in Rats

Trans-ε-viniferin (εVin) is a resveratrol dimer exhibiting promising biological activities for human health. Its bioavailability being low, the development of encapsulation methods would be used to overcome this issue. The aim of this study was to measure the consequences of the encapsulation of εVin in multilamellar liposomes on its pharmacokinetic parameters, metabolism and tissue distribution in rats. After oral administration of εVin (20 mg/kg body weight), either as free or encapsulated forms, plasmas were sequentially collected (from 0 to 4 h) as well as liver, kidneys and adipose tissues (4 h after administration) and analyzed by LC-HRMS. The glucuronide metabolites (εVG) were also produced by hemisynthesis for their quantification in plasma and tissues. The encapsulation process did not significantly modify the pharmacokinetic parameters of εVin itself. However, a significant increase of the T1/2 was noticed for εVG after administration of the encapsulated form as compared to the free form. An accumulation of εVin and εVG in adipose tissues was noticed, and interestingly a significant increase of the latter in the mesenteric one after administration of the encapsulated form was highlighted. Since adipose tissues could represent storage depots, and encapsulation allows for prolonging the exposure time of glucuronide metabolites in the organism, this could be of interest to promote their potential biological activities.

New C-Glycosidic Ellagitannins Formed upon Oak Wood Toasting; Identification and Sensory Evaluation

In the courses of studies on ellagitannin changes during oak wood toasting, two C-glycosidic ellagitannins were isolated from the french oak wood for the first time. These two compounds exhibited [M-H]- ion peak at m/z 1055.0631 (compound A) and at m/z 1011.0756 (compound B). A compound is named Castacrenin E and is produced by Castacrenin D oxidation. Castacrenin D is a vescalagin with an additional aromating ring to the C-1 through a C-C bond. These compounds are not only found under laboratory conditions but also in commercial oak wood representing different toasting methods and sizes. Their levels are conditioned by oak wood dimensions and toasting degree. The wood pieces with the smallest size present almost two times more compounds A and B. Moreover, the compound B is the only compound to be present in medium toasting temperatures of the smallest wood pieces. Both of them can influence either astringency sensation or bitterness taste.

Validation of a mass spectrometry method to identify and quantify ellagitannins in oak wood and cognac during aging in oak barrels

Ellagitannins are the main extractible phenolic compounds in oak wood; the monomers vescalagin and castalagin, lyxose/xylose-bearing monomers grandinin and roburin E, dimers roburins A and D and lyxose/xylose-bearing dimers roburins B and C are the principal ones. These compounds are responsible for the high durability of wood and may contribute to the organoleptic quality of wines and spirits (color, astringency, bitterness). Despite their importance, their presence and forms in distilled spirits are not well known. The aim of this work was therefore to develop and validate a method to identify and quantify oak wood ellagitannins in Cognac using high liquid chromatography-triple quadrupole (LC-QQQ) analysis. The method was validated using vescalagin as the standard and by studying sensitivity, linearity in working range, intraday repeatability, and intraday precision in order to quantify individual ellagitannins in this complex matrix.

Impact of Different Stoppers on the Composition of Red and Rosé Lagrein, Schiava (Vernatsch) and Merlot Wines Stored in Bottle

Different technical cork stoppers (blend of natural cork microgranules, one-piece natural cork, agglomerated natural cork, technical cork 1+1) were compared to evaluate the effects on the phenolic, volatile profiles and dissolved oxygen in three red (Merlot, Lagrein red, St. Magdalener) and one rosé (Lagrein rosé) wines, which were stored in bottles for 12 months. Gallic acid, caffeic acid, p-coumaric acid, trans-resveratrol, glutahionyl caftaric acid and protocatechuic acid did not vary remarkably during the first three months, whereas at six months a net increase was reported, followed by a clear decrease at 12 months. The same trend was observed in Lagrein rosé, but only for gallic acid. The total anthocyanins content decreased during the storage period in the four wines. Isopentyl acetate, 1-hexanol, ethyl hexanoate, 2-phenylethyl alcohol, diethyl succinate, ethyl octanoate and ethyl decanoate were the main volatile compounds. The sum of alcohols decreased in all four of the wines. The esters decreased in Merlot; however, they increased in Lagrein rosé, Lagrein red and St. Magdalener during the storage. Univariate and multivariate statistics and a sensory discriminant triangle test displayed similar influences of the different stoppers on the phenolic and volatile compounds during the whole storage duration. The changes detected in the phenolic and volatile concentrations were presumably due to the non-oxygen-mediated reactions occurring during 12 months of storage in bottle.

Effect of enological treatments on phenolic and sensory characteristics of red wine during aging: Micro-oxygenation, sulfur dioxide, iron with copper and gelatin fining

This work aimed to study long-term impact of micro-oxygenation and/or different aging treatments: (i) high SO₂, (ii) high Fe with Cu and (iii) gelatin fining on Plavac mali red wine phenolic and in-mouthfeel sensory development in barrels and furthermore in bottles. Results showed that outcomes of micro-oxygenation strongly depend on aging treatments. High SO₂ concentration during aging in barrels and bottles delayed typical phenolic changes and slightly contributed to astringency and lower color intensity, particularly in wine that was not micro-oxygenated. High metal concentrations and gelatin fining promoted intensive polymerization of proanthocyanins and a lower percentage of prodelphinidins after long-term aging in barrels. Also, flavan-3-ol and anthocyanins transformation rates in micro-oxygenated wines of both treatments significantly differed from their controls. Gelatin fining proved to be a very effective treatment for astringency reduction, particularly when combined with micro-oxygenation, but fined wines after long term aging in bottles showed lower color intensity.

Oenological tannins to prevent Botrytis cinerea damage in grapes and musts: Kinetics and electrophoresis characterization of laccase

Enzymatic parameters (K_M and V_max), residual activity, effect of bentonite and electrophoresis characterization of laccase in the presence of different oenological tannins (OT) were investigated in relation to B. cinerea negative effects in grapes and musts. Five OT were tested (gallotannin, ellagitannin, quebracho, grape-skin and grape-seed) in comparison with ascorbic acid (AA), sulfur dioxide (SO₂) and bentonite. We added OT, AA, SO₂ and bentonite to botrytized must obtained by inoculation of grapes with B. cinerea strain 213. Laccase activity was measured by the syringaldazine method at different concentrations of substrate. Enzymatic parameters were determined using Michaelis-Menten and Lineweaver-Burk plots. The B. cinerea strain was also grown in a liquid medium for laccase production. Molecular weight of laccases and effect of OT upon these laccases were studied by SDS-PAGE. Results confirm that bentonite, contrary to OT, did not permit to reduce laccase activity. Regardless the tannin considered, V_max, K_M and laccase activity were reduced and gallotannin, grape-skin and grape-seed tannin presented the greatest ability. Efficiency of grape-seed tannin addition in order to reduce the laccase activity, was comparable to that of AA or SO₂ at the typical doses employed in oenology for each one. Oenological tannins appear to be excellent processing aids to prevent laccase effects and contribute to reduce the use of SO₂ in grapes and musts.

Grapes and their derivatives in modulation of cognitive decline: a critical review of epidemiological and randomized-controlled trials in humans

With an increase in life expectancy, the incidence of chronic degenerative pathologies such as dementia has progressively risen. Cognitive impairment leads to the gradual loss of skills, which results in substantial personal and financial cost at the individual and societal levels. Grapes and wines are rich in healthy compounds, which may help to maintain homeostasis and reduce the risk of several chronic illnesses, including dementia. This review analyzed papers that were systematically searched in PubMed, MEDLINE, Embase, and CAB-Abstract, using the association between grapes (or their derivatives) and their effects on cognitive functions in humans. Analysis was restricted to epidemiological and randomized-controlled studies. Consumption of grape juice (200-500 mL/day) and/or light-to-moderate wine (one to four glasses/day) was generally associated with improved cognitive performance, while the results for other alcoholic beverages were controversial and inconclusive. Bioactive molecules contained in grapes and wine were also considered, with particular attention paid to resveratrol. Due to the relatively high doses required (150-1000 mg/day) for bioactivity coupled with its low bioavailability, resveratrol is only one of the possible grape-derived compounds that may partly underpin the beneficial effects of grapes on the central nervous system.

High-Performance Liquid Chromatography-Hydrogen/Deuterium Exchange-High-Resolution Mass Spectrometry Partial Identification of a Series of Tetra- and Pentameric Cyclic Procyanidins and Prodelphinidins in Wine Extracts

A solid-phase extraction method was applied for the identification of a series of unconventional crown (macrocyclic) B-type proanthocyanidin tetramers (m/z 1169.2557, 1185.2507, 1201.2456, and 1217.2405) and pentamers (m/z 1457.3191, 1473.3140, 1489.3090, 1505.3039, and 1521.2988) containing (epi)catechins only (procyanidins) or (epi)catechins and (epi)gallocatechins (prodelphinidins). These compounds were identified in red wine by high-performance liquid chromatography-high-resolution mass spectrometry coupled with online hydrogen/deuterium exchange (HDX) after purification with a C18 solid-phase extraction phase from the original wine sample. The number and type of monomer units present in each procyanidin and prodelphinidin are discussed on the basis of the experimental measured masses, their retention time distribution among observed isomers, tandem mass spectrometry fragmentations, and the HDX-induced shift of the theoretical monoisotopic mass. The elution in reverse-phase high-performance liquid chromatography shifted to lower retention times when the ratio of (epi)gallocatechin units in these molecules increased with respect to the content of (epi)catechin units, as a consequence of the increase of polarity.

Speciation Analysis of Organolead Compounds in Wine by Capillary Gas Chromatography/Microwave-Induced-Plasma Atomic Emission Spectrometry

A method was developed for the speciation analysis of ionic organolead compounds in wine. The analytes were extracted as diethyldithiocarbamate complexes into hexane and propylated with a Grignard reagent. The derivatized extract was analyzed by capillary gas chromatography/microwave-induced-plasma atomic emission spectrometry. The method of standard additions was used for calibration to correct for variable recoveries and signal en hancements. Red, rosé, and white wines from southern France were analyzed. Trimethyllead was the ubiquitous species. The wines made from grapes grown close to industrial zones showed elevated concentrations of ethyllead species. The con centrations of methyllead and ethyllead found in wines were compared with the concentrations of organolead found in rain water and plant sap collected in the viticultural regions. The ratio of methyllead to ethyllead in wines greatly exceeded the same ratio found in atmospheric deposits.

Is it scientifically justifiable to exclude wine and/or unfermented grape derivatives from the diet of consumers with or at risk of developing type-2 diabetes?

This narrative review investigates whether low/moderate consumption of wine/grape's derivatives can be part of T2D individuals daily diet.

Neuroprotective Effects of Pomegranate Juice against Parkinson's Disease and Presence of Ellagitannins-Derived Metabolite-Urolithin A-In the Brain

Pomegranate juice is a rich source of ellagitannins (ETs) believed to contribute to a wide range of pomegranate’s health benefits. While a lot of experimental studies have been devoted to Alzheimer disease and hypoxic-ischemic brain injury, our knowledge of pomegranate’s effects against Parkinson’s disease (PD) is very limited. It is suggested that its neuroprotective effects are mediated by ETs-derived metabolites—urolithins. In this study, we examined the capability of pomegranate juice for protection against PD in a rat model of parkinsonism induced by rotenone. To evaluate its efficiency, assessment of postural instability, visualization of neurodegeneration, determination of oxidative damage to lipids and α-synuclein level, as well as markers of antioxidant defense status, inflammation, and apoptosis, were performed in the midbrain. We also check the presence of plausible active pomegranate ETs-derived metabolite, urolithin A, in the plasma and brain. Our results indicated that pomegranate juice treatment provided neuroprotection as evidenced by the postural stability improvement, enhancement of neuronal survival, its protection against oxidative damage and α-synuclein aggregation, the increase in mitochondrial aldehyde dehydrogenase activity, and maintenance of antiapoptotic Bcl-xL protein at the control level. In addition, we have provided evidence for the distribution of urolithin A to the brain.

Disease Resistant Bouquet Vine Varieties: Assessment of the Phenolic, Aromatic, and Sensory Potential of Their Wines

The search for grape varieties resistant to diseases and to climatic changes notably concerns the wine industry. Nine monovarietal wines from new red grape varieties resistant to cryptogamic diseases (downy and powdery mildews) were evaluated in terms of their total phenolic, anthocyanin and proanthocyanidin contents, anthocyanin profile, volatile composition, and sensory attributes. Thus, the question remains, will these hybrid grapes (≥97.5% of Vitis vinifera genome) lead to wines with organoleptic properties similar to those of Vitis vinifera wines that consumers are used to? Total phenolic (1547–3418 mg GA/L), anthocyanin (186–561 mg malvidin/L), and proanthocyanidin (1.4–4.5 g tannins/L) contents were in broad agreement with those previously described in the literature for monovarietal wines produced with well-known red grape varieties (Cabernet Sauvignon, Merlot, Syrah). With regard to fruity aroma, ethyl esters of straight-chain fatty acids (530–929 μg/L) stood out clearly as the major volatile components for all hybrid wines considered. Sensory analysis revealed significant differences (p < 0.05) for visual aspect, aroma, flavor, global balance, astringency, and body. Overall, these new hybrid grape varieties are not only resistant to cryptogamic diseases, but also present enough potential to become quality wines, since their phenolic and volatile attributes are close to those of common red monovarietal wines.

Relative abundances of novel cyclic prodelphinidins in wine depending on the grape variety

The identification of cyclic B-type procyanidins in grape and wine was recently disclosed. Some of these were also found in berries of totally different vegetal species (eg, Vaccinium sp.). However, presence of a wider class of these cyclic condensed tannin compounds with variably substituted monomers has never been addressed so far. Here, an extended list of oligomeric cyclic proanthocyanidins (PAC) bearing variable substitution patterns on the main flavan-3-ol unit has been searched in wines. Nearly 7600 theoretical structures were calculated and searched in red and white wine samples made from different grape varieties. Moreover, a hydrogen/deuterium exchange approach (already applied to a cyclic tetrameric procyanidin) coupled to high-resolution mass spectrometry was applied to confirm their cyclic B-type structure rather than a non cyclic A-type structure, otherwise isomeric and undistinguishable by LC-MS alone. The main group of novel cyclic PAC observed is shown to contain (epi)gallocatechin beside (epi)catechin as the constituent monomers.

Volatile, phenolic, and sensory profiles of in-amphorae Chardonnay wine by mass spectrometry and chemometric analysis

The sensory properties, the phenolic composition, and the volatile profile of Chardonnay wine made in amphorae were compared with the wine obtained in large wooden barrels (2000 L) and small toasted barrels (225 L). Hierarchical cluster analysis and principal component analysis built on the phenolics and volatiles variables allowed to group effectively the samples according to the winemaking material used. In-amphorae wines showed more abundant catechin and caffeic acid and less abundant caftaric acid and trans-coutaric acid. Condensation reactions proceeded in the wood containers leading to esterification of organic acids with ethanol and alcohols, whereas in-amphorae wines were characterized by a higher content of free phenolic acids and higher volatile alcohols. Among the volatile compounds, ramified ethyl esters contributed mostly in samples made in small toasted barrels, whereas nonbranched ethyl esters contributed more for the samples made in large wooden tanks; higher alcohols contributed more for the in-amphorae wine. The sensory analysis showed negligible differences induced by the in-amphorae vinification with respect to the wooden one. Four variables could distinguish wines made in-amphorae compared with the other containers: solvent and acetone (SA), astringent/pungency (AP), fruity (FR), and color intensity (CI). The overall approach proposed here is promising for future developments of innovative types of Chardonnay wine blends.

Grape Pomace: Antioxidant Activity, Potential Effect Against Hypertension and Metabolites Characterization after Intake

Observational studies indicate that the intake of polyphenol-rich foods improves vascular health, thereby significantly reducing the risk of hypertension and cardiovascular disease (CVD). Therefore, the aim of this study was to analyse the remained potential of grape by-products from important Rhône Valley red wine cultivars: Grenache, Syrah, Carignan, Mourvèdre and Alicante. For that, six different extracts from grape pomaces, selected by their antioxidant activity, were studied in vivo during six weeks with spontaneously hypertensive rats (SHR). Extracts used in SHR1, SHR2 and SHR6 groups presented a « rebound effect » on systolic blood pressure, whereas the other extracts do not change it significantly. The bioavailability of Grenache (GRE1) (EA70) seed pomace extract (SHR1 group), Mouvendre (MOU) (EA70) skin pomace extract (SHR5 group) and Alicante (ALI) (EA70) skin pomace extract (SHR6 group) was studied by High Performance Liquid Chromatography with Photodiode Array detector and Electrospray Ionization Mass Spectrometer (HPLC-PDA-ESI-MSⁿ) in urine, plasma and tissues to search differences on the metabolism of the different extracts intake.

Chemical characterization, antioxidant properties and oxygen consumption rate of 36 commercial oenological tannins in a model wine solution

The chemical composition (CC), antioxidant capacity (AC) and oxygen consumption rate (OCR) of 36 different commercial tannins were measured. The CC was analyzed by total polyphenol index, Bate-Smith, methyl-cellulose, Folin-Ciocalteu, OIV official method and phloroglucinolisis. The AC was measured by different methods (ABTS, CUPRAC, DPPH, FRAP, ORAC) using Trolox as standard. The OCR was measured using a non-invasive method based on luminescence. The results indicate that it is possible to obtain differentiation between procyanidins/prodelphinidins, profisetinidins/prorobinetidins, gallotannins and ellagitannins by PCA based on their CC data. It is also possible to separate condensed from hydrolysable tannins by PCA based on their AC data. The results show that ellagitannins are the fastest oxygen consumers of the various oenological tannins, followed in descending order by condensed tannins and finally gallotannins. The combination of CC, AC and OCR analyses enable to classify tannins according to their effectiveness in protecting wines against oxidation.

Reduced obesity, diabetes, and steatosis upon cinnamon and grape pomace are associated with changes in gut microbiota and markers of gut barrier

Increasing evidence suggests that polyphenols have a significant potential in the prevention and treatment of risk factors associated with metabolic syndrome. The objective of this study was to assess the metabolic outcomes of two polyphenol-containing extracts from cinnamon bark (CBE) and grape pomace (GPE) on C57BL/6J mice fed a high-fat diet (HFD) for 8 wk. Both CBE and GPE were able to decrease fat mass gain and adipose tissue inflammation in mice fed a HFD without reducing food intake. This was associated with reduced liver steatosis and lower plasma nonesterified fatty acid levels. We also observed a beneficial effect on glucose homeostasis, as evidenced by an improved glucose tolerance and a lower insulin resistance index. These ameliorations of the overall metabolic profile were associated with a significant impact on the microbial composition, which was more profound for the GPE than for the CBE. At the genus level, Peptococcus were decreased in the CBE group. In the GPE-treated group, several key genera that have been previously found to be linked with HFD, metabolic effects, and gut barrier integrity were affected: we observed a decrease of Desulfovibrio, Lactococcus, whereas Allobaculum and Roseburia were increased. In addition, the expression of several antimicrobial peptides and tight junction proteins was increased in response to both CBE and GPE supplementation, indicating an improvement of the gut barrier function. Collectively, these data suggest that CBE and GPE can ameliorate the overall metabolic profile of mice on a high-fat diet, partly by acting on the gut microbiota.

Resveratrol, human health and winemaking perspectives

Resveratrol, (3, 5, 4'-trihydroxystilbene) is a non-flavonoid polyphenol stilbene synthesized by plants when damaged by infectious diseases or ionizing radiation. Although present in more than seventy plant species, grapes and wine are the major dietary contributors of resveratrol, responsible for 98% of the daily intake. In 1992, Renaud and De Lorgeril first linked wine polyphenols, including resveratrol, to the potential health benefits ascribed to regular and moderate wine consumption (the so called "French Paradox"). Since then, resveratrol has received increasing scientific interest, leading to research on its biological actions, and to a large number of published papers, which have been collected and discussed in this review. The relatively low amounts of resveratrol measured in wine following moderate consumption, however, may be insufficient to mitigate biological damage, such as that due to oxidative stress. On this basis, the authors also highlight the importance of viticulture and the winemaking process to enhance resveratrol concentrations in wine in order to bolster potential health benefits.

In Vitro Glucuronidation and Sulfation of ε-Viniferin, a Resveratrol Dimer, in Humans and Rats

ε-Viniferin is a resveratrol dimer that possesses antioxidant or anti-inflammatory activities. However little is known about the metabolism of this oligostilbene. This study was thus undertaken as a first approach to identify and characterize the metabolites of ε-viniferin and to describe the kinetic profile of their appearance in humans and rats. The glucuronides and sulfates of ε-viniferin were first obtained by chemical hemi-synthesis and were fully characterized by UPLC-MS and NMR spectroscopy. Then, ε-viniferin was incubated with human or rat S9 liver fractions that led to the formation of four glucuronoconjugates and four sulfoconjugates. In both species, ε-viniferin was subjected to an intense metabolism as 70 to 80% of the molecule was converted to glucuronides and sulfates. In humans, the hepatic clearance of ε-viniferin (V_max/K_m) for glucuronidation and sulfation were 4.98 and 6.35 µL/min/mg protein, respectively, whereas, in rats, the hepatic clearance for glucuronidation was 20.08 vs. 2.59 µL/min/mg protein for sulfation. In humans, three major metabolites were observed: two glucuronides and one sulfate. By contrast, only one major glucuronide was observed in rats. This strong hepatic clearance of ε-viniferin in human and rat could explain its poor bioavailability and could help to characterize its active metabolites.

Comparison between Malolactic Fermentation Container and Barrel Toasting Effects on Phenolic, Volatile, and Sensory Profiles of Red Wines

Ellagitannin and anthocyanin profiles, woody volatile composition, and sensory properties of wines in which malolactic fermentation (MLF) took place in barrels or stainless steel tanks, have been compared after 12 months of barrel aging. Three different barrel toastings were evaluated. Barrel-fermented wines generally presented 1.2-fold higher total phenolics, whereas tank-fermented wines exhibited 1.1- and 1.2-fold greater total proanthocyanidin and anthocyanin contents, respectively. Concerning ellagitannin composition, the barrel toasting effect seemed to be more important than differences due to MLF container. Certain woody and fruity volatiles varied significantly (p < 0.05) depending on whether MLF occurred in barrels or tanks. Barrel-fermented wines were preferred in the mouth, whereas olfactory preference depended on barrel toasting. This is the first study that evaluates the impact of oak wood during MLF on ellagitannin wine composition, as well as the barrel toasting effect on wine attributes during aging when MLF occurred whether in barrels or in tanks.

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.

Grape Polyphenols' Effects in Human Cardiovascular Diseases and Diabetes

The consumption of fruits and vegetables, as well as foods enriched in bioactive compounds and nutraceuticals, has increased due to consumers' interest in the relevance of food composition for human health. Considerable recent interest has focused on bioactive phenolic compounds in grape, as they possess many biological activities, such as antioxidant, cardioprotective, anticancer, anti-inflammation, anti-ageing and antimicrobial properties. Observational studies indicate that the intake of polyphenol-rich foods improves vascular health, thereby significantly reducing the risk of hypertension, and cardiovascular disease (CVD). Other researchers have described the benefits of a grape polyphenol-rich diet for other types of maladies such as diabetes mellitus. This is a comprehensive review on the consumption of polyphenolic grape compounds, concerning their potential benefits for human health in the treatment of cardiovascular diseases and diabetes.

Spectroscopic and theoretical investigations of phenolic acids in white wines

Model solutions of white wines containing phenolic acids have been investigated by means of UV-vis, laser induced fluorescence and Raman spectroscopic techniques. In order to interpret the spectra, density functional theory calculations of phenolic acids have been performed. This work demonstrates that only hydroxynamic acids are in resonance with a laser excitation line with 325nm wavelength and are therefore at the origin of the strong enhancement of the Raman light scattering. Real white wines also display such resonance Raman scattering so that their content in hydroxycinnamic acids may be quite precisely determined. The analysis of the Raman spectrum of a real dry white wine reveals qualitatively the preponderance in its composition of p-coumaric and caftaric acids.

Impact of post-harvest ozone treatments on the skin phenolic extractability of red winegrapes cv Barbera and Nebbiolo (Vitis vinifera L.)

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.

Chemical Affinity between Tannin Size and Salivary Protein Binding Abilities: Implications for Wine Astringency

Astringency perception, as an essential parameter for high-quality red wine, is principally elicited by condensed tannins in diversified chemical structures. Condensed tannins, which are also known as proanthocyanidins (PAs), belong to the flavonoid class of polyphenols and are incorporated by multiple flavan-3-ols units according to their degree of polymerization (DP). However, the influence of DP size of PAs on astringency perception remains unclear for decades. This controversy was mainly attributed to the lack of efficient strategies to isolate the PAs in non-galloylated forms and with individual degree size from grape/wine. In the present study, the astringency intensity of purified and identified grape oligomeric tannins (DP ranged from 1 to 5) was firstly explored. A novel non-solid phase strategy was used to rapidly exclude the galloylated PAs from the non-galloylated PAs and fractionate the latter according to their DP size. Then, a series of PAs with individual DP size and galloylation were purified by an approach of preparative hydrophilic interaction chromatography. Furthermore, purified compounds were identified by both normal phase HPLC-FLD and reverse phase UHPLC-ESI-Q-TOF. Finally, the contribution of the astringency perception of the individual purified tannins was examined with a salivary protein binding ability test. The results were observed by HPLC-FLD and quantified by changes in PA concentration remaining in the filtrate. In summary, a new approach without a solid stationary phase was developed to isolate PAs according to their DP size. And a positive relationship between the DP of PAs and salivary protein affinity was revealed.

Trace element bioavailability, yield and seed quality of rapeseed (Brassica napus L.) modulated by biochar incorporation into a contaminated technosol

BACKGROUND AND AIMS

Rapeseed (Brassica napus L.) is a Cd/Zn-accumulator whereas soil conditioners such as biochars may immobilize trace elements. These potentially complementary soil remediation options were trialed, singly and in combination, in a pot experiment with a metal(loid)-contaminated technosol.

METHODS

The technosol [total content in mg kg(-1) Zn 6089, Cd 9.4, Cu 110, and Pb 956] was either amended (2% w/w) or not with a poultry manure-derived biochar. Rapeseed was cultivated for both soil treatments during 24 weeks up to harvest under controlled conditions.

RESULTS

Biochar incorporation into the technosol promoted the As, Cd, Cu, Mo, Ni, Pb and Zn solubility. It decreased foliar B, Cu and Mo concentrations, and Mo concentration in stems, pericarps and seeds. But, it did not impact neither the biomass of aerial rapeseed parts (except a decrease for seeds), nor their C (except a decrease for stems), seed fatty acid, seed starch and soluble sugar contents, and antioxidant capacity in both leaves and seeds. Biochar amendment increased the phytoextraction by aerial plant parts for K, P, and S, reduced it for N, Ca, B, Mo, Ni and Se, whereas it remained steady for Mg, Zn, Fe, Mn, Cu, Cd and Co.

CONCLUSIONS

The biochar incorporation into this technosol did not promote Cd, Cu and Zn phytoextraction by rapeseed and its potential oilseed production, but increased the solubility of several metal(loid)s. Here Zn and Cd concentrations in the soil pore water were decreased by rapeseed, showing the feasibility to strip available soil Zn and Cd in combination with seed production.

Variations in oxygen and ellagitannins, and organoleptic properties of red wine aged in French oak barrels classified by a near infrared system

During wine aging in barrels, antioxidant molecules from wood, such as ellagitannins, are solubilized and react with wine molecules and oxygen. However, their concentrations are highly variable. Oxygen is an important factor, as it plays a role in wine parameters and organoleptic perceptions. Five barrel modalities were used; three polyphenol indices (IP), classified using the NIRS procedure, and three grain qualities. Barrels were equipped with windows to measure the oxygen using luminescence technology. The ellagitannin concentrations in the wine and its organoleptic properties were monitored. Oxygen concentrations decreased quickly during the first 8days of aging and this phenomenon was significantly more marked in barrels with a higher IP and medium grain. The ellagitannin concentrations were believed to be correlated with wood classification and oxygen consumption. Furthermore, the organoleptic properties were significantly impacted, as the wine with the lowest ellagitannin level was described as less astringent, bitter, woody, and smoky/toasty.

Effect of irrigation regime on perceived astringency and proanthocyanidin composition of skins and seeds of Vitis vinifera L. cv. Syrah grapes under semiarid conditions

In this work, the effect of water availability on astringency of seed and skin extracts of Vitis vinifera cv. Syrah berries under the typical semiarid conditions of Greece was investigated. Moreover, astringency was assessed in relation to proanthocyanidin composition. For this purpose, three irrigation treatments were applied starting at berry set through harvest of 2011 and 2012: full irrigation (FI) at 100% of crop evapotranspiration, deficit irrigation (DI) at 50% and non-irrigated (NI). FI skin and seed extracts were perceived significantly more astringent than NI. Total phenol, total tannin, (+)-catechin, (-)-epicatechin and procyanidin C1 concentrations were positively correlated with astringency. Positive correlations were also obtained among astringency and average degree of polymerization and proportion of the extension units of shorter tannins while astringency of larger tannins was correlated with the proportion of terminal units. On the contrary, total anthocyanin and epigallocatechin contents were negatively correlated with astringency.

Drinking pattern of wine and effects on human health: why should we drink moderately and with meals?

Epidemiological studies examining the effects of alcoholic beverages on human health may be unclear if they do not take into account drinking pattern parameters such as beverage type, regular moderateversusbinge drinking and drinking with meals.

Polysaccharides and lignin from oak wood used in cooperage: Composition, interest, assays: A review

It is widely accepted that alcoholic beverage quality depends on their ageing in premium quality oak wood. From the choice of wood to beverage ageing, through the different steps in cask manufacturing, many factors should be considered. One of the biggest challenge in cooperages is to take into account all these factors. Most of the studies are interested in phenolic compounds, extracted during ageing and especially involved in wine oxidation, colour, and sensory properties such as astringency and bitterness. Oak aroma volatile compounds have also been the subject of numerous studies. These compounds of interest are part of low molecular weight compounds which represent 2%-10% of oak wood composition. However, three polymers constitute the main part of oak wood: cellulose, hemicellulose and lignin. As far as we are aware, few studies concerning the role of these major macromolecules in oak wood have been published previously. This article reviews oak wood polysaccharides and lignin, their potential interest and different assays used to determine their content.

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.

Occurrence and formation kinetics of pyranomalvidin-procyanidin dimer pigment in Merlot red wine: impact of acidity and oxygen concentrations

Once released from red grape skins, anthocyanins undergo various chemical reactions leading to the formation of more stable pigments such as pyranoanthocyanin, as well as other derivatives. Among these pigments, pyranoanthocyanins linked directly to flavanol dimers have been detected and identified in aged Port wine but not in dry red wine. These pigments are very important with regard to the wine color evolution since they are involved in wine color evolution and stabilization. During this investigation, the occurrence in dry red wine of two pyranomalvidin-procyanidin dimer has been established by low and high resolution HPLC-UV-MS analysis. Moreover, the impact of acidity and oxygen levels on their formation in red wine has been estimated. After four months of evolution, the results showed that, for the same pH, the quantity of this pigment was correlated with oxygen concentrations. Moreover, for the same quantity of oxygen, the concentration of this pigment was related to the acidity level.

Wine by-products: phenolic characterization and antioxidant activity evaluation of grapes and grape pomaces from six different French grape varieties

Grenache, Syrah, Carignan Noir, Mourvèdre, Counoise and Alicante Bouchet grape seeds and skins, harvested in 2009 and 2010 in the Rhône valley area of France, and their respective pomaces remaining after vinification, were analyzed for their phenolic composition and antioxidant activity. The polyphenol content was quantified by HPLC and the Folin-Ciocalteu assay. The antioxidant potential was measured with four different assays: ORAC, FRAP, ABTS and DPPH. Seeds contained higher amounts of total polyphenols, up to 44.5 mg of gallic acid equivalent [GAE]/g dry weight in Alicante pomace, than skin extracts. The maximum total phenolic in skins was 31.6 mg GAE/g dry weight detected in 2010 Alicante pomace. Seeds also had the highest antioxidant capacity. HPLC analysis revealed that, despite the vinification process, pomaces still contained an appreciable amount of proanthocyanidins as well as several anthocyanin glycosides. Alicante and Syrah proved to be the varieties of most interest in terms of their potential development for nutraceutical purposes.