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Lipids are a diverse group of organic compounds that serve essential roles due to their biological functions for all prokaryotic and eukaryotic organisms. Despite the fundamental role of lipid class in plants, there is still a relatively low level of knowledge regarding the composition of grape lipids. This research represents the first investigation into the lipids of the Croatian grape variety ‘Maraština’ (Vitis vinifera L.), employing a targeted approach and the UHPLC-MS/MS method to conduct a comprehensive analysis of the lipid profile of grape skins. The study investigated the profile of free fatty acids, glycerolipids, glycerophospholipids, triterpenoids, sphingolipids, and free fatty acid esters in eleven vineyards located along the cultivation area of ‘Maraština’ variety (Dalmatia, Croatia). Grape skins from vineyards that were exposed to more sunlight and higher daily temperature during the vegetation period mainly resulted in a richer profile of free fatty acids. Among lipids, ‘Maraština’ grape skins were characterized mainly by a triterpenoid compound; oleanolic acid (249.49 µg/g of FW), and free fatty acids, especially palmitic acid C16:0 (26.09 µg/g of FW), and lignoceric acid C24:0 (12.40 µg/g of FW). Hierarchical clustering analysis represented valuable insights into the diversity of lipids in ‘Maraština’ grape skin.

In recent years, the number of patients with neurodegenerative illness such as Alzheimer’s disease (AD) has increased with the aging of the population. In this study, we evaluated the effect of Grape skin extract (GSE) on neurotypic SH-SY5Y cells as an in vitro AD model, murine neurospheres as an ex vivo neurogenesis model and SAMP8 mice as an in vivo AD model. Our in vitro result showed that pre-treatment of SH-SY5Y cells with GSE ameliorated Aβ-induced cytotoxicity. Moreover, GSE treatment significantly decreased the number of neurospheres, but increased their size suggesting reduced stem cell self-renewal but increased proliferation. Our in vivo Morris water maze test indicated that GSE improves learning and memory in SAMP8 mice. To detect proliferation and newborn neurons, we measured BrdU+ cells in the dentate gyrus (DG). GSE treatment increased the number of BrdU+ cells in the DG of SAMP8 mice. Finally, we showed that GSE induced a decrease in inflammatory cytokines and an increase in neurotransmitters in the cerebral cortex of SAMP8 mice. These results suggested that GSE increased neurogenic zone proliferation and memory but decreased oxidative stress associated with pro-inflammatory cytokines in aging, thus protecting neurons.

Trop grožđa je proizvodni ostatak vinarija koji je jeftin, ali bogat izvor biološki aktivnih spojeva, kao što su fenolni spojevi. Njihova biološka funkcija pripisana je antioksidativnom, protuupalnom i antimikrobnom učinku. Kožica i sjemenke bobice grožđa su važan izvor fenolnih spojeva koje biljke sintetiziraju kao produkte sekundarnog metabolizma. S obzirom na to da fenolni spojevi imaju antioksidativno djelovanje, nazivaju se antioksidansima te onemogućuju djelovanje slobodnih radikala u ljudskom tijelu i tako sprječavaju posljedice oksidativnog stresa. Sintetski antioksidansi imaju štetan učinak na zdravlje ljudi pa se ekstrakti iz proizvodnih ostataka vinarija koji obiluju fenolnim spojevima nameću kao bolja prirodna alternativa sintetičkim antioksidansima. Konvencionalna ekstrakcija otapalom je najčešće korištena metoda izolacije fenolnih spojeva, međutim ova metoda predstavlja veliko opterećenje za okoliš budući da se za njezinu provedbu troše velike količine organskog otapala. Kao alternativa konvencionalnoj metodi ekstrakcije se javljaju tzv. zelene metode ekstrakcije, kao što je mikrovalovima potpomognuta ekstrakcija koja nudi visoku učinkovitost ekstrakcije u kratkom vremenu te manju potrošnju otapala. Učinkovitost mikrovalne ekstrakcije ovisi o izboru otapala, trajanju izlaganja uzorka mikrovalovima, jakosti mikrovalne pećnice, temperaturi i sastavu samog uzorka. Kao nedostatak mikrovalne ekstrakcije pojavljuje se cijena opreme, ograničena primjena samo onih otapala koja imaju sposobnost interakcije s mikrovalovima i potreba za dodatnom jediničnom operacijom odvajanja ekstrakta od uzorka. Grape pomace is a production residue from wineries that is an inexpensive but abundant source of biologically active compounds, such as phenolic compounds. Their biological function is attributed to antioxidant, anti-inflammatory and antimicrobial effects. The skin and seeds of grape berries are an important source of phenolic compounds synthesized by plants as products of secondary metabolism. Since phenolic compounds have antioxidant effects, they are called antioxidants and prevent the action of free radicals in the human body, thus preventing the consequences of oxidative stress. Synthetic antioxidants have a harmful effect on human health, so extracts from winery production residues rich in phenolic compounds are used as a better natural alternative to synthetic antioxidants. Conventional solvent extraction is the most commonly used method to isolate phenolic compounds, but this method poses a great burden on the environment because large amounts of organic solvents are consumed in its application. As an alternative to the conventional extraction method, so-called green extraction methods such as microwaveassisted extraction have been introduced, which offers high extraction efficiency in a short time and lower solvent consumption. The efficiency of microwave extraction depends on the choice of solvent, the duration of microwave exposure of the sample, the power of the microwave oven, the temperature and the composition of the sample itself. The disadvantages of microwave extraction are the cost of the equipment, the limited use of solvents capable of interacting with microwaves, and the need for an additional step to separate the extract from the sample.

Polyphenols are organic compounds that can be found in food, especially in fruits, vegetables, and their products. It was shown that their presence significantly affects the properties of food products and that the consumption of food rich in phenolic compounds has a beneficial effect on human health. The subjects of this research were polyphenols: anthocyanins, flavonols, and flavan-3-ols in the skin of grapevine variety Regent. Polyphenols from grape skins were extracted via microwave-assisted extraction (MAE) and matrix solid-phase dispersion (MSPD) as unconventional and green techniques. Therefore, the main aim of this work was to optimize the conditions for the extraction of polyphenolic compounds from grape skin using MAE and MSPD. The extracts were analyzed using high-performance liquid chromatography with a diode array detector and fluorescence detector. Analyses showed that MAE was a very effective method for extracting polyphenolic compounds from grape skin with 10 mL of 60% ethanol for 5 min at 40 °C. The best results for the MSPD extraction of polyphenolic compounds from grape skin were obtained with phenyl as an MSPD sorbent with 10 mL of acetonitrile:water 50:50 v/v as an elution solvent. This scientific research can be used for the better use of grapes as a basis for obtaining flavonoids for commercial purposes.

In this study, seeds, skins and stems of the red wine grape varieties Boğazkere, Cabernet Sauvignon, Merlot, Nero d’Avola, Sangiovese and Syrah grown in Turkey were analysed for their phenolic compounds. The highest total phenolic compound and DPPH were found in the stem of Boğazkere respectively as 62550 mg GAE/kg dw and 614 µmol/g dw; the highest ABTS, (+)-catechin, (–)-epicatechin were detected in the seed of Nero d’Avola respectively as 617 µmol trolox/g dw, 8650 mg/kg and 1902 mg/kg dw; the highest total anthocyanin and rutin were measured in the skin of Boğazkere respectively as 143.52 mg/kg dw and 9692 mg/kg dw; the highest quercetin was found in the seed of Boğazkere as 49.21 mg/kg dw and the highest trans-resveratrol was measured in the stem of Syrah as 61.56 mg/kg dw. Scientific Research Projects Coordinatorship of Ankara University - 11B4347003 WOS:000623982100002 Q4

Resveratrol, a phenolic compound possessing vital biological activities such as anti-cancer, is present abundantly in grape skin, a waste produced during the processing of grape juice. The objectives of this study were to prepare resveratrol-gold nanoparticles and a resveratrol nanoemulsion from grape skin and study their inhibition effects on pancreatic cancer cells BxPC-3. The spherical-shaped citrate gold nanoparticles (GNPs) and resveratrol-gold nanoparticles (R-GNPs) were, respectively, prepared with a surface plasmon resonance peak at 528 and 538 nm, mean particle size of 20.8 and 11.9 nm, and zeta-potential at −32.7 and −66.7 mV, by controlling an appropriate concentration of citrate/resveratrol and gold chloride as well as stirring time and temperature. The resveratrol nanoemulsion, composed of soybean oil, Tween 80, and sucrose fatty acid ester in glycerol and water, possessed a high storage stability with a mean particle size of 14.1 nm, zeta-potential of −49.7 mV, and encapsulation efficiency of 95.5%. An antiproliferation study revealed that both R-GNPs and resveratrol nanoemulsion could effectively inhibit the growth of pancreatic cancer cells BxPC-3, with the latter showing a higher inhibition effect. Western blot analysis implied that both can down-regulate expressions of cyclin A, cyclin B, CDK1, and CDK2 and up-regulate expressions of p53 and p21, accompanied by enhancing cytochrome C expression, decreasing BcL-2 expression, increasing Bax expression, and leading to the elevation of caspase-8, caspase-9, and caspase-3 activities for cell apoptosis execution. Future research is needed to study the inhibition of pancreatic tumors in vivo by R-GNPs and resveratrol nanoemulsions.

Consumer interest in health-promoting foods has prompted researchers to use wine by-products to increase food’s functional characteristics. This research aims to examine the skin bioactivities of Samos white (small-berry Muscat) and red (Augustiatis) grape skin extracts (M-GSkE, A-GSkE). Total phenolic content, antiradical activity, the inhibition of plasma oxidation and platelet aggregation, and the phenolic profile were examined. A-GSkE and M-GSkE showed high total phenolics (1.19 ± 0.13 vs. 2.12 ± 0.23 mM GAE), antiradical activity (7.7 ± 0.4 vs. 6.6 ± 0.3 μM GAE for ABTS; 31.12 ± 0.8 vs. 26.4 ± 1.0 μM GAE for DPPH), resistance to plasma oxidation (5.7 ± 0.4 vs. 1.1 ± 0.2 μM GAE), and antithrombotic activity (19.7 ± 0.1 vs. 26.6 ± 0.2 μM GAE). Ferulic (41.3 ± 0.1 > 13.2 ± 0.1 μg/g DM), vanillic (26.3 ± 1.7 > 12.2 ± 1.2 μg/g DM), and gallic (16.6 ± 0.1 > 8.4 ± 2.9 μg/g DM) acids along with ε-viniferin (3.6 ± 0.4 > 2.8 ± 0.3 μg/g DM) were identified in higher content in A-GSkE. Catechin (59.8 ± 1.5 μg/g DM), chlorogenic acid (43.8 ± 0.9 μg/g DM), and resveratrol (0.83 ± 0.13 μg/g DM) were identified only in M-GSkE, while caffeic acid 19.8 ± 0.4 μg/g DM) and daidzein (16.8 ± 0.1 μg/g DM) were identified only in A-GSkE. The specialized bioactivities researched in two previously unexplored Samos’ wine grape skin extracts give them added value. The valorization of such by-products promises a sustainable future in the food sector of local communities and an improvement in local public health.

In the last years, the possibility to exploit the high added value bioactive compounds obtained by the solid residues of the winemaking process in cosmetic, food supply and pharmaceutical field was explored. To enhance the biocompatibility of the final products and reduce the environmental impact of traditional extraction routes, researchers attempted at developing sustainable and green extraction processes. In the present work, the feasibility of employing NaDES (Natural Deep Eutectic Solvents) as a cheap and non-toxic alternative to traditional solvents for the extraction of bioactive compounds from winery wastes of Merlot marc was studied. Furthermore, a two-level factorial design was used to study the single and combined effect of process variables, namely, solid to liquid ratio dry grinding time and extraction time, on the extraction yield. Experimental show that, in the range studied, solid to liquid ratio has a predominant effect and both grinding and extraction times have a slightly appreciable effect on the extraction yield.

To explore the effect of pectolytic enzyme application on polysaccharide size and colloidal interactions, rosé wines were prepared from pressed Shiraz grape juice, and red wines were made from the same juice by the addition of skins and seeds from fresh pressings. A pectolytic enzyme preparation containing primarily polygalacturonase and side-activities of arabinase and pectin lyase was used. Enzyme treatment enhanced the contribution of high molecular weight (≈ 200 kDa) polysaccharides rich in mannose and glucose (mannoproteins) and removed arabinose-rich polysaccharides of intermediate (≈ 40 kDa) size. Enzyme application reduced the molecular weight average of a class of smaller polysaccharides of approximately 6 kDa (rhamnogalacturonan II). All wines had similar particle sizes, but enzyme treatment markedly reduced particle concentration in wines, particularly in rosé wines. Wine polysaccharides were purified and when reconstituted in model wine, showed reduced particle concentration in response to enzyme treatment. Aggregation of polysaccharide in the presence of seed tannin was also markedly reduced by enzyme treatment. The results indicated that changes in structure introduced by the enzyme affected wine colloidal properties, potentially increasing polysaccharide solubility.

Grape pomace is one of the most abundant solid by-products generated during winemaking. A lot of products, such as ethanol, tartrates, citric acid, grape seed oil, hydrocolloids, bioactive compounds and dietary fiber are recovered from grape pomace. Grape pomace represents a major interest in the field of fiber extraction, especially pectin, as an alternative source to conventional ones, such as apple pomace and citrus peels, from which pectin is obtained by acid extraction and precipitation using alcohols. Understanding the structural and functional components of grape pomace will significantly aid in developing efficient extraction of pectin from unconventional sources. In recent years, natural biodegradable polymers, like pectin has invoked a big interest due to versatile properties and diverse applications in food industry and other fields. Thus, pectin extraction from grape pomace could afford a new reason for the decrease of environmental pollution and waste generation. This paper briefly describes the structure and composition of grape pomace of different varieties for the utilization of grape pomace as a source of pectin in food industry.

EVALUATION OF THE TOTAL CONCENTRATION AND THE BIOACCESSIBLE FRACTION OF METALS IN SAMPLES OF GRAPE SKINS OF CULTIVARS TANNAT AND CABERNET SAUVIGNON BY MIP OES. This paper describes the evaluation of the total concentration of Ba, Bi, Ca, Cd, Co, Cr, Cu, Fe, K, Mn, Pb e Zn and the bioaccessible fraction of Ba, Cu, Fe, Mn, Pb and Zn in samples of grape skins from different cultivars (Vitis Viníferas Tannat and Cabernet Sauvignon) by MIP OES. For the determination of total concentration, acid decomposition with a reflux system adapted to the digestion tubes in the oxidizing medium of HNO3 and H2O2 were used. The accuracy of the method was verified by recovery tests, whose values ranged from 80 to 120%, as well as through a comparative method in closed system. Bi, Cd and Cr showed values for total content below the LOD or below the values acceptable for health while Pb is higher than 0.2 mg kg-1, for both cultivars. To evaluate the bioacessible fraction, the gastrointestinal system was simulated using an in vitro procedure, and its performance was assessed considering the bioaccessible fraction (supernatant) and the non-bioaccessible fraction, whose sum should be closed to the total concentration, and the results obtained were between 81 and 120%. Both cultivars showed similar values for the bioaccessible fractions (~13.5 – 53% of the total content).

Grape seeds (GS) and grape skins (GK) are natural sources of polyphenols with featured antioxidant capacity. An experiment was conducted to investigate the effect of these polyphenol sources in diets formulated to contain the same total extractable grape polyphenol content on growth performance, protein and extractable polyphenol digestibility, plasma and meat α- and γ-tocopherol and thigh meat oxidation in broiler chickens. Five experimental diets were formulated: control, control + vitamin E (200 mg/kg), 30 g/kg GS diet, 110 g/kg GK diet, GS + GK diet (a mixture of 24.4 g/kg GS and 13.1 g/kg GK designed to simulate a reconstituted grape pomace). Feeding chickens with 110 g/kg GK reduced (p &lt, 0.001) daily weight gain, worsened (p &lt, 0.001) feed conversion ratio, increased (p &lt, 0.001) non-extractable polyphenol content in the ileum and in the excreta and decreased (p &lt, 0.05) ileal protein digestibility. Regardless of the grape polyphenol source used, the inclusion of grape byproducts in the diets led to an increase of total extractable polyphenol contents in the ileum (p &lt, 0.01) and the excreta (p &lt, 0.001), which resulted (p &lt, 0.001) in a decrease of extractable polyphenol digestibilities. Alpha- and gamma-tocopherol concentrations increased (p &lt, 0.001) in plasma and in seven-day stored meat in birds fed the diet combining GS and GK with respect to the control group. As it happened with the vitamin E supplementation, feeding the combination of GS and GK also reduced (p &lt, 0.001) the concentration of the lipid peroxidation marker (malondialdehyde) in the stored meat of chickens.

This review is focused on the study of the effects of grape seed and skin extract (GSSE) on human health. GSSE contains high concentrations of important polyphenolic substances with high biological activity. This review is a summary of studies that investigate the effects of GSSE on diabetes mellitus, cardiovascular disease and cancer, its neuroprotective effect, and its effects on the gastrointestinal tract and other health complications related to these diseases. The results of the studies confirm that the anti-inflammatory, antiapoptotic, and pro-proliferative effects of “Vitis vinifera L.” seed extract reduce the level of oxidative stress and improve the overall lipid metabolism.

With the increasing needs of clean water supplies, the use of biomass wastes and residues for environmental remediation is essential for environmental sustainability. In this study, the residues from winery and citrus juice industries, namely grape skin and orange peel, respectively, were first converted to hydrochars by hydrothermal carbonization (HTC) and then a cationic dye (methylene blue) adsorption was studied on hydrochars. Hydrochars from both feedstocks were produced at three different temperatures (180, 220, and 250 °C) and a fixed residence time (1 h) to evaluate the hydrochar’s performance on the dye adsorption. The hydrochars were characterized in terms of their pH, pH at point of zero charge (pHPZC), surface functionalities, and surface area. A batch adsorption study of the dye was carried out with variable adsorbate concentration, pH, and temperature. Two adsorption isotherms namely Langmuir and Freundlich models were fitted at 4, 20, and 36 °C. The thermodynamic properties of adsorption (Gibbs free energy (ΔG), enthalpy (ΔH) and entropy (ΔS)) were evaluated from the isotherms fittings. Results showed that the dye adsorption on both hydrochars was significant and followed Langmuir isotherm. The maximum adsorption capacity on citrus waste hydrochar was higher than the winery waste hydrochar at any corresponding HTC temperature. Although hydrochars showed the lowest surface area (46.16 ± 0.11 and 34.08 ± 1.23 m2/g for citrus and winery wastes, respectively) at 180 °C, their adsorption was the highest, owing to their maximum density of total oxygen functional groups (23.24 ± 0.22 and 32.69 ± 1.39 µmol/m2 for citrus and winery wastes, respectively), which decreased with the increase in HTC temperature. This research shows a sustainable route for the production of highly effective adsorbent materials at lower HTC temperatures from citrus and winery wastes.

In the past few years, research efforts have focused on plant exploitation for deriving some valuable compounds. Extraction has been usually performed using petrochemical and volatile organic solvents, but nowadays, increased recognition of environmental pollution has prompted the utilization of green solvents as alternatives. Therefore, the aim of the present study was to exploit deep eutectic solvents (DES) (choline chloride: citric acid and choline chloride: glucose) as solvents for extracting valuable phenolic antioxidants from grapes. Investigation was conducted on ten grape varieties, observing seeds and skin as different matrix. Total polyphenol content (TPC) was determined by Folin-Ciocalteu spectrophotometric microassay. Antioxidant activity was investigated using four different tests and results were combined in a unique Antioxidant Composite Index (ACI) to reveal comprehensive information about this biological activity. Polyphenol compounds were identified and quantified with the aim of HPLC-diode array detector (DAD). Overall results support that DES (particularly choline chloride: citric acid) were comparable to conventional solvent, and in most cases even outperformed acidified aqueous ethanol (concerning extraction efficiency and antioxidant activity). Regardless of varietal distinctions, grape seeds have higher antioxidant capacity compared to grape skin, and such findings are according to their phenol compound concentrations.

This review is focused on the study of the effects of grape seed and skin extract (GSSE) on human health. GSSE contains high concentrations of important polyphenolic substances with high biological activity. This review is a summary of studies that investigate the effects of GSSE on diabetes mellitus, cardiovascular disease and cancer, its neuroprotective effect, and its effects on the gastrointestinal tract and other health complications related to these diseases. The results of the studies confirm that the anti-inflammatory, antiapoptotic, and pro-proliferative effects of "Vitis vinifera L." seed extract reduce the level of oxidative stress and improve the overall lipid metabolism., [IGA-ZF/2020-AP006]; [CZ.02.1.01/0.0/0.0/16_017/0002334]

Nowadays, the use of plant-based by-products obtained after food processing has gained importance, as these products are nutritious and cheap. The aim of this study was to determine the effects of grape skin and seed powders with different particle sizes (100, 200, 288 and 415 μm) on the texture, sensory, color, and rheological properties of soft candies. According to the results, the particle size of the grape-derived components was a significant factor for the texture parameters, especially hardness, adhesiveness, chewiness, and resilience. In sensory analyses, samples containing grape seed and skin powder with a particle size of 100 and 200 μm received the highest score and particles were not felt by the panelists. Also, the use of grape seed and skin powder decreased the L* value of the soft candies compared to the control group, which was parallel to the decrease in the particle size. It was found that r values of model fitting of rheological data can be correlated with sensory results. In conclusion, it was shown that grape-derived components can be successfully used in the formulation of soft candy if particle size was adjusted below 200 μm.

The effects of including extruded linseed in pig diets supplemented with either polyphenol-rich red grape skin extract (3 g kg-1) or synthetic antioxidants (200 mg kg-1 α- tocopheryl acetate plus 0.21 mg kg-1 of selenium) on shelf-life of pork stored in modified atmosphere packaging (MAP) at different oxygen concentrations (0 and 70%) were evaluated. Linseed reduced n-6/n-3 fatty acid ratio in lipids of backfat and loin. Color parameters, pH, weight losse, oxidative stability (TBARS), did not differ between antioxidants neither in raw, nor in cooked, nor in stored muscle. High oxygen concentration in MAP increased TBARS and ΔE, yielding redder meat.

Dye-sensitized solar cells (DSSCs), a powerful system to convert solar energy into electrical energy, suffer from the high cost of the Pt counter electrode and photosensitizer. In this study, the dual application of waste grape skin is realized by employing the grape skin and its extract as the carbon source of the carbon-based counter electrode and photosensitizer, respectively. The ultraviolet–visible absorption and Fourier transform infrared spectroscopy verify the strong binding between the dye molecules (anthocyanins) in the extract and the TiO2 nanostructure on the photoanode, contributing to a high open-circuit voltage (VOC) value of 0.48 V for the assembled DSSC device. Moreover, the waste grape skin was subjected to pyrolysis and KOH activation and the resultant KOH-activated grape skin-derived carbon (KA-GSDC) possesses a large surface area (620.79 m2 g−1) and hierarchical porous structure, leading to a high short circuit current density (JSC) value of 1.52 mA cm−2. Additionally, the electrochemical impedance spectroscopy reveals the efficient electron transfer between the electrocatalyst and the redox couples and the slow recombination of electrolytic cations and the photo-induced electrons in the conduction band of TiO2. These merits endow the DSSC with a high photovoltaic efficiency of 0.48%, which is 33% higher than that of a common Pt-based DSSC (0.36%). The efficiency is also competitive, compared with some congeneric DSSCs based on other natural dyes and Pt counter electrode. The result confirms the feasibility of achieving the high-value application of waste grape skin in DSSCs.

This work investigated the structural, biochemical, and molecular characteristics of grape skin cell wall during ripening, related to susceptibility to Botrytis cinerea. The comparative study between the two main grape cultivars in Champagne region, Pinot noir and Chardonnay, quantified: (1) the maturity and physical profile of grape skin, (2) the morphological characteristics, (3) soluble pectic polysaccharides located in grape skin cell walls, and (4) the gene expression of the two main degrading enzymes (VvPME1 and VvPG1) and PME activity. During the maturation period, the grape skins of the two cultivars appear different in their structure and composition. Chardonnay is characterized by higher relative humidity (RH) and level of VvPG1 expression, lower disease incidence and penetrometry values, and thicker cell walls than Pinot noir skins. Thus, the cell wall composition is sufficiently different between grape varieties from the same area to allow their discrimination and could be used to better manage the harvest date.

The effect of 2% grape seed and 2% grape skin powder added to chicken thigh patties stored at 4°C was assessed by measuring lipid oxidation, total phenolic content, pH, color changes and sensory attributes. The addition of these grape by-products to the patties lowered pH values and significantly reduced in lightness, redness and yellowness compared with the control. However, the addition of grape seed and skin significantly improved the oxidative stability of raw chicken patties due to higher total phenolic content, grape seed being more effective than skin in this regard. The phenolic content of these samples remained stable even after cooking. The acceptability of the chicken meat in general was not affected by the addition of grape by-products. These results show that grape seed and grape skin could potentially be used as natural antioxidants in raw chicken patties and would be accepted by consumers., The authors thank the MINECO, and CSIC for financial support of Projects AGL2012-31355/GAN and the Intramural 2014470E073. Also we are grateful the CAM and ESI Funds for the financial support the project MEDGAN-CM S2013/ABI2913). Thanks to the MIUR and UNIMOL for the PhD fellowship of Maria Nardoia.

[EN] The determination of the detailed flavanol composition in food matrices is not a simple task because of the structural similarities of monomers and, consequently, oligomers and polymers. The aim of this study was the development and validation of an HPLC-MS/MS−multiple reaction monitoring (MRM) method that would allow the accurate and precise quantification of catechins, gallocatechins, and oligomeric proanthocyanidins. The high correlation coefficients of the calibration curves (>0.993), the recoveries not statistically different from 100%, the good intra- and interday precisions (

Benign prostatic hyperplasia (BPH) is a common chronic disease of the urinary system among elderly men. Especially, the metabolic imbalance of androgen in elderly men is one of the leading causes of BPH. Dihydrotestosterone (DHT) and converted testosterone by 5-&alpha, reductase type 2 (5AR2), binding with androgen receptor (AR), affect prostate proliferation and growth. In BPH, levels of androgen signaling-related protein expression are shown highly. Androgen signaling induces the overexpression of prostate-specific antigen (PSA) and cell proliferation factor such as proliferating cell nuclear antigen (PCNA) and cyclin D1. Grape skin anthocyanins are well known for their antioxidative, anti-cancer, anti-diabetes, anti-inflammatory, antimicrobial, and anti-aging activities. Polymerized anthocyanin (PA) downregulated the expression of androgen signaling-related proteins such as 5AR2, AR, and PSA in LNCaP cell lines. Furthermore, we investigated the effects on PA in testosterone propionate-induced BPH rat experiments. The oral administration of PA decreased the prostate weight in rats with TP-induced BPH. PA decreased the AR, 5AR2, SRC1, PSA, PCNA, and cyclin D1 expression in prostate tissues and the serum DHT levels, ameliorated the BPH-mediated increase of Bcl-2 expression, and increased the Bax expression. These results suggest that PA may be a potential natural therapeutic agent for BPH treatment.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2022-03-27T16:58:55Z No. of bitstreams: 1 2019 - Yineth Ru?z Garc?a.pdf Made available in DSpace on 2022-03-27T16:58:56Z (GMT). No. of bitstreams: 1 2019 - Yineth Ru?z Garc?a.pdf Previous issue date: 2010-03-05 CAPES - Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior The Alicante Bouschet (Vitis vinifera L.) is a grape cultivar with high anthocyanin content in both pulp and skin, which has been used for the production of wines in the Brazilian semi-arid region. This activity generates many residues, still rich in phenolic compounds, mainly anthocyanins. The general objective of the present work was to obtain and characterize a concentrated liquid extract from cv. Alicante Bouschet (Vitis vinifera L.) cultivated in the semi-arid region of Brazil. To this, the most adequate solid-liquid extraction conditions were determined to obtain an extract rich in phenolic compounds with high antioxidant capacity. The concentrated liquid extract was characterized by the phenolic compounds profile by HPLC-DAD, antioxidant capacity by ABTS?+ and ORAC methods, instrumental color by reflectance and antimicrobial activity in vitro using the well diffusion test. The stability of the monomeric anthocyanins and extract color was evaluated during storage at low temperatures. The bioaccessibility of the phenolic compounds was evaluated using an in vitro digestion model. The influence of the extract on the metabolic activity and modulation of the human gut microbiota was studied using an in vitro colonic fermentation model. The extract was added as a dye in a red berries preparation that was added to an ice cream. The stability of the monomeric anthocyanins and of the color was evaluated after the elaboration processes and during the storage of these products. Sensory acceptance of ice creams added with red berries preparation with and without added liquid extract of grape skin was evaluated by using a 9-point hedonic scale. The conditions selected as the most adequate for the extraction were: temperature of 40 ?C, 50% v/v ethanol and 2% m/v citric acid. Malvidin-3-O-(6-O-p-coumaroyl)-glucoside and malvidin-3-O-glucoside were the major anthocyanins. The purple-reddish dark and opaque color of the extract remained stable under freezing at -18 ? C for up to 45 days of storage but was less stable under refrigeration at 5 ? C (15 days). The grape skin extract inhibited the growth of all tested bacteria, being more effective against Staphylococcus aureus. The bioaccessibility of monomeric anthocyanins and flavanols was low (23% and 25%, respectively) after in vitro digestion. However, phenolic acids were highly bioaccessible (> 100%) after in vitro digestion and after colonic fermentation, resulting in high antioxidant activity in these phases. Although 24 h of in vitro colonic fermentation were not enough to stimulate the microbiota growth, the production of short chain fatty acids (SCFAs) in fermented extract indicate that the extract favored the metabolic activity of the intestinal microbiota. Therefore, the extract could have a potential prebiotic effect for the long-term modulation of the microbiota. The grape skin concentrated liquid extract could be used as a natural dye in red berries preparations and ice cream. A uva Alicante Bouschet (Vitis vinifera L.) ? uma cultivar tintoreira com elevado teor de antocianinas na casca e na polpa, que tem sido usada para a produ??o de vinhos no semi?rido do Brasil. Esta atividade gera muitos subprodutos ainda ricos em compostos fen?licos, principalmente antocianinas. O objetivo geral do presente trabalho foi a obten??o e caracteriza??o de um extrato l?quido concentrado a partir de casca de uva cv. Alicante Bouschet (Vitis vinifera L.) cultivada no semi?rido do Brasil. Para isso, foram determinadas as condi??es da extra??o s?lido-l?quido mais adequadas para obter um extrato rico em compostos fen?licos com elevada capacidade antioxidante. O extrato l?quido concentrado foi caracterizado quanto ao perfil de compostos fen?licos por CLAE-DAD, capacidade antioxidante pelos m?todos ORAC e ABTS?+, cor instrumental por reflect?ncia e atividade antimicrobiana in vitro usando a t?cnica de difus?o em po?os. A estabilidade das antocianinas monom?ricas e da cor do extrato foi avaliada durante a estocagem a baixas temperaturas. A bioacessibilidade dos compostos fen?licos foi avaliada mediante mediante um modelo est?tico de digest?o in vitro. A influ?ncia do extrato sobre a atividade metab?lica e a modula??o da microbiota intestinal humana foi estudada mediante um modelo est?tico de fermenta??o col?nica in vitro. O extrato foi adicionado como corante em um preparado de frutas vermelhas adicionado a um sorvete. A estabilidade das antocianinas monom?ricas e da cor destes produtos foram avaliadas ap?s os processos de elabora??o e durante a estocagem. Foi realizado um teste de aceita??o sensorial dos sorvetes adicionados de preparado de frutas vermelhas com e sem adi??o do extrato l?quido concentrado de casca de uva usando uma escala hed?nica de 9 pontos. Os resultados indicaram que as condi??es mais adequadas para a extra??o foram: temperatura de 40 ?C, concentra??o de etanol de 50% v/v e de ?cido c?trico de 2% m/v. As antocianinas foram os compostos fen?licos majorit?rios no extrato, predominando a malvidina-3-O-(6-O-p-cumaroil)-glicos?deo e a malvidina-3-O-glicos?deo. A cor roxa avermelhada escura e opaca do extrato permaneceu est?vel sob congelamento a ?18 ?C at? 45 dias de estocagem, por?m pouco est?vel sob refrigera??o a 5 ?C (15 dias). O extrato de casca de uva inibiu o crescimento de todas as bact?rias testadas, sendo mais efetivo contra Staphylococcus aureus. A bioacessibilidade de antocianinas monom?ricas e flavan?is foi baixa (23% e 25%, respectivamente), ap?s a digest?o in vitro. Contudo, os ?cidos fen?licos foram bioacess?veis (> 100%) ap?s a digest?o e ap?s a fermenta??o col?nica in vitro, resultando em uma elevada atividade antioxidante nestas fases. Apesar de que 24 horas de fermenta??o col?nica in vitro n?o foram suficientes para estimular a multiplica??o dos microrganismos da microbiota intestinal, a produ??o de ?cidos graxos de cadeia curta sugere que o extrato de casca de uva favoreceu a atividade metab?lica da microbiota e poderia ter um efeito prebi?tico potencial na modula??o da microbiota em longo prazo. O extrato l?quido concentrado de casca de uva poderia ser usado como corante natural em preparados de frutas vermelhas para adi??o em sorvetes.

In this research dataset, we summarize for the first time volatile organic compounds (VOCs) emitted in vivo from ripening wine grapes. We studied four cold-hardy cultivars grown in the Midwestern U.S.: St. Croix, Frontenac, Marquette, and La Crescent. These cultivars have gained popularity among local growers and winemakers, but still very little is known about their performance compared with long-established V. vinifera grapes. Volatiles were collected using two novel approaches: biogenic emissions from grape clusters on a vine and single grape berries. A third approach was headspace collection of volatiles from crushed grapes. Solid-phase microextraction (SPME) was used to collect volatiles. Vacuum-assisted SPME was used in the case of single grape berry. Collected VOCs were analyzed using separation and identification on a gas chromatograph mass spectrometer (GC-MS). More than 120 VOCs were identified using mass spectral libraries. The dataset provides evidence that detecting biogenic emissions from growing grapes is feasible. The dataset provides a record of temporal and spatial variability of VOCs, many of which could potentially impart aroma and flavor in the wine. The number of VOCs detected followed the order from single berry (the least) to crushed berry (the most). Thus, more information for potential use in harvesting in order to obtain the desired flavor is found in data from crushed grapes.

To investigate the changes in wine chemical composition, sensory quality, and style induced by various levels of skin disruption and contact with oxygen during grape processing, five treatments were applied: whole grape cluster pressing in semi‐reductive conditions (WCP‐R), whole grape cluster pressing in standard conditions (WCP), standard grape mash pressing as a control (GMP), light (LOX), and heavy oxidation of grape juice (HOX). Produced wines were subjected to analysis of phenols (HPLC‐DAD) and volatiles (HS‐SPME‐GC/MS), as well as quantitative descriptive sensory analysis. WCP‐R wines stood out with the highest amounts of hydroxycinnamates and preserved aromas, and the highest intensities of positive sensory attributes. Both WCP and LOX treatments significantly reduced phenols when compared to GMP, while HOX treatment was detrimental in general. Apparently, the level of contact with oxygen exhibited a predominant effect on hydroxycinammates and aromas, while the level of grape skin disruption affected primarily hydroxybenzoic acids and flavan‐3‐ols.

Made available in DSpace on 2019-07-19T00:42:45Z (GMT). No. of bitstreams: 1 TESEYINETHRUIZGARCIA2019.pdf: 9579555 bytes, checksum: ac6f05a3466bad7444a91cef3d8820a1 (MD5) Previous issue date: 2019 Tese (Doutorado em Ciência e Tecnologia de Alimentos) - Universidade Federal Rural do Rio de Janeiro, Seropédica, 2019. Orientadora: Lourdes Maria Correa Cabral; Coorientação: Renata Valeriano Tonon

Highly soluble maltodextrin-encapsulated grape skin phenolics comprising anthocyanins and less hydrophilic flavonoids were added as an ingredient to apple puree. Upon formulation, heat treatments were applied to achieve 3-14 decimal reductions (D) of the target microorganism (Alicyclobacillus acidoterrestris). A storage study was performed at 15-35°C for 1month. Monomeric anthocyanins were retained at 100% after the 3 D treatment, while anthocyanin retention decreased to 72% with increasing heating intensity until 14 D. During storage, the concentration of monomeric anthocyanins decreased following first-order kinetics (k25°C=34.4d(-1), activation energy=51.0kJ/mol). The flavanols were more stable than the monomeric anthocyanins. The hydroxycinnamic acid, dihydrochalcone and flavonol contents did not change. The fortified puree had a two-fold higher reducing capacity with respect to apple puree. Overall, this ingredient could meet the industrial demand for sustainable colouring agents and health promoting compounds.

Grape pomace is a winemaking by-product that can be used to extract oenological tannins. Recently, some grape skin tannins were shown to contain very high amounts of two polyfunctional thiol precursors (3-S-glutathionylhexan-1-ol, 3-S-cysteinylhexan-1-ol) whose free forms are responsible for appreciated tropical-like flavours. This study shows that an oxidative treatment (no SO2) of white grape pomace and the presence of grape leaves and stems can increase the content of the above mentioned precursors. Moreover, it shows significant differences between Sauvignon Blanc, Gewuerztraminer and Mueller-Thurgau grape pomace for the 3-mercaptohexan-1-ol precursors and 4-S-cysteinyl-4-methylpentan-2-one. The grape cultivar is crucial, but the technological ability of enhancing the level of the volatile thiol precursors simply by treating the grape marc in different ways is a promising and powerful tool for the production of potentially flavouring tannins intended for food and beverage industry.

Producción Científica, A bio-electronic tongue has been developed to evaluate the phenolic content of grape residues (seeds and skins) in a fast and easy way with industrial use in mind. A voltammetric electronic tongue has been designed based on carbon resin electrodes modified with tyrosinase combined with electron mediators. The presence of the phenoloxydase promotes the selectivity and specificity towards phenols. The results of multivariate analysis allowed discriminating seeds and skins according to their polyphenolic content. Partial least squares (PLS) has been used to establish regression models with parameters related to phenolic content measured by spectroscopic methods i.e., total poliphenol content (TPC) and Folin–Ciocalteu (FC) indexes. It has been shown that electronic tongue can be successfully used to predict parameters of interest with high correlation coefficients (higher than 0.99 in both calibration and prediction) and low residual errors. These values can even be improved using genetic algorithms for multivalent analysis. In this way, a fast and simple tool is available for the evaluation of these values. This advantage may be due to the fact that the electrochemical signals are directly related to the phenolic content., Ministerio de Ciencia Innovación y Universidades-FEDER (grants RTI2018-097990-B-100 and BES-2016-077825), Junta de Castilla y León-FEDER (grant VA275P18) y (Infraestructuras Red de Castilla y León (INFRARROJOS) UVA01)

Grape pomace is an agro-industrial by-product from the production of must (grape juice) by pressing whole grapes. In order to evaluate the seeds and skins of the grape pomace, it must first be dried and then separated in a screen machine. The drying of pomace is an important and necessary process for the optimum separation of seeds. The main purpose of this study was to determine the optimum drying process for obtaining high-quality grape seed oil. In this research, open air and solar energy drying methods were compared in terms of water activity, total bacterial and mold-yeast count, along with the chemical and fatty acid compositions of pressed grape residues. Oleic acid and linoleic acid contents ranged from 16.56-16.96% and 71.45-71.96%, respectively. Antioxidant activities ranged from 2.33-2.80 μmol trolox/g. The results showed that the drying methods did not decrease the nutritional quality of grape residues and prevented microbial growth by decreasing water activity to below 0.60. El orujo de uva es un subproducto agroindustrial de la producción de mosto (jugo de uva) al prensar las uvas enteras. Para poder evaluar las semillas y las pieles del orujo de uva, primero debe secarse y luego separarse mediante una máquina de tamizado. El secado del orujo es un proceso importante y necesario para una separación óptima de las semillas. El objetivo principal de este estudio fue determinar el proceso de secado óptimo para obtener aceites de semillas de uva de alta calidad. En este trabajo, los métodos de secado al aire libre y la energía solar de los residuos de uva prensados se compararon en términos de actividad de agua, recuento total de bacterias y moho, así como la composición de ácidos grasos. Los contenidos de ácido oleico y linoleico variaron entre 16,56-16,96% y 71,45-71,96%, respectivamente. Las actividades antioxidantes variaron entre 2,33-2,80 μmol trolox/g. Los resultados mostraron que los métodos de secado no disminuyeron la calidad nutricional de los residuos de la uva y evitaron el crecimiento microbiano al disminuir la actividad del agua por debajo de 0,60.

U ovom je radu ispitana mogućnost uporabe osam različitih imidazolijevih ionskih kapljevina kao novih otapala za ekstrakciju flavonoida iz pokožice grožđa, te su rezultati uspoređeni s konvencionalnom ekstrakcijom pomoću organskog otapala. Struktura aniona, kationa i koncentracije ionskih kapljevina značajno su utjecali na iskorištenje ekstrakcije. Najveća koncentracija proantocijanidina dobivena je pomoću 2,5 mol/L 1-butil-3- -metilimidazolijevog bromida [C4mim][Br], a antocijana pomoću 2,5 mol/L 1-etil-3- -metilimidazolijeva bromida [C2mim]. Statistički bitno veće koncentracije ukupnih i svih slobodnih antocijana dobivene su ekstrakcijom pomoću 2,5 mol/L [C2mim][Br] i 2,5 mol/L 1- -metilimidazolijevog hidrogen sulfata [HM][HSO4], u usporedbi s konvencionalnim otapalom. Nadalje, 2,5 mol/L [C4mim][Br] i 2.5 mol/L 1-(4-sulfobutil)-3-metilimidazolijevog hidrogen sulfata [S4mim][HSO4] imali su znatno veću selektivnost prema antocijanin-3-O- -acetilmonoglukozidu i antocijanin-3-(6-O-p-kumaril)monoglikozidu., In this study, eight different types of imidazolium-based ionic liquids (ILs) were applied as new solvents in the extraction of flavonoids from grape skin, and compared to the conventional organic solvent extraction that was not reported earlier. The structure of anions, cations and concentration of ILs significantly affected extraction yields. The highest mass fractions of proanthocyanidins and anthocyanins were obtained with 2.5 mol/L of 1-butyl-3-methylimidazolium bromide [C4mim][Br] and 2.5 mol/L of 1-ethyl-3-methylimidazolium bromide [C2mim][Br], respectively. The studied ILs provided an excellent preliminary result in the extraction of anthocyanins. Significantly higher mass fractions of total and all free anthocyanins were extracted with 2.5 mol/L of [C2mim][Br] and 2.5 mol/L of 1-methylimidazolium hydrogen sulfate [mim][HSO4] than with conventional solvent with the exception of anthocyanin-3-O-acetylmonoglucosides in the latter. On the other hand, 2.5 mol/L of [C4mim][Br] and 2.5 mol/L of 1-(4-sulfobutyl)-3-methylimidazolium hydrogen sulfate [sC4mim][HSO4] showed significantly higher selectivity towards anthocyanin-3-O-acetylmonoglucosides and anthocyanin-3-(6-O-p-coumaroyl)monoglucosides.

The goal of this study was to investigate the characteristics of grape skin extract (GSE) spray dried with different carriers: maltodextrin (MD), gum Arabic (GA) and skim milk powder (SMP). The grape skin extract was obtained from winery by-product of red grape variety Prokupac (Vitis vinifera L.). The morphology of the powders, their thermal, chemical and physical properties (water activity, bulk and tapped densities, solubility), as well as release studies in different pH conditions were analyzed. Total anthocyanin content and total phenolic content were determined by spectrophotometric methods. MD and GA-based microparticles were non-porous and spherical, while SMP-based ones were irregularly shaped. The process of spray drying Prokupac GSE using these three carriers produced powders with low water activity (0.24-0.28), good powder characteristics, high yields, and solubility higher than 90%. The obtained dissolution/release profiles indicated prolonged release of anthocyanins and phenolic compounds in different mediums, especially from GSE/GA microparticles. These results have shown that grape skin as the main by-product of wine production could be used as a source of natural colorants and bioactive compounds, and microencapsulation as a promising technique for the protection of these compounds, their stabilization in longer periods and prolonged release.

In this research, we propose a novel concept for a non-destructive evaluation of volatiles emitted from ripening grapes using solid-phase microextraction (SPME). This concept is novel to both the traditional vinifera grapes and the cold-hardy cultivars. Our sample models are cold-hardy varieties in the upper Midwest for which many of the basic multiyear grape flavor and wine style data is needed. Non-destructive sampling included a use of polyvinyl fluoride (PVF) chambers temporarily enclosing and concentrating volatiles emitted by a whole cluster of grapes on a vine and a modified 2 mL glass vial for a vacuum-assisted sampling of volatiles from a single grape berry. We used SPME for either sampling in the field or headspace of crushed grapes in the lab and followed with analyses on gas chromatography-mass spectrometry (GC-MS). We have shown that it is feasible to detect volatile organic compounds (VOCs) emitted in-vivo from single grape berries (39 compounds) and whole clusters (44 compounds). Over 110 VOCs were released to headspace from crushed berries. Spatial (vineyard location) and temporal variations in VOC profiles were observed for all four cultivars. However, these changes were not consistent by growing season, by location, within cultivars, or by ripening stage when analyzed by multivariate analyses such as principal component analysis (PCA) and hierarchical cluster analyses (HCA). Research into aroma compounds present in cold-hardy cultivars is essential to the continued growth of the wine industry in cold climates and diversification of agriculture in the upper Midwestern area of the U.S.

[EN] The aim of this work was to address the air-borne application of power ultrasound in the convective drying of grape skin, a by-product of winemaking. For that purpose, convective drying experiments were carried out on red grape skin at 40, 50, 60 and 70 C with (21.7 kHz, 45 W) and without power ultrasound application. The kinetic intensification was evaluated by modeling the drying kinetics using empirical and diffusion models. Meanwhile, the quality of the dried product was determined by obtaining ethanolic extracts and assessing the total phenolic content and antioxidant capacity by means of the FRAP method. Moreover, individual polyphenols were identified by HPLC-DAD-ESI-MS/MS and a Partial Component Analysis (PCA) was performed in order to elucidate the relationships between the measured variables that were related to bioactive content. Both temperature and ultrasound application had a significant (p < 0.05) influence on the drying kinetics, which were satisfactorily described by both the Peleg and diffusion models. In addition, both factors significantly (p < 0.05) influenced the total phenolic concentration and antioxidant capacity of the extracts. Ultrasound application reduced the antioxidant potential, probably due to oxidase activation and cell degradation. Bioactive potential, on the other hand, was increased as a consequence of hightemperature drying, leading in particular to a greater release of malvidin 3-O-b-D-galactoside., The authors acknowledge the financial support of the Spanish Ministerio de Economia y Competitividad and ERDF and it is a program of the European Commission ERDF-European Commission (Ref. DPI2012-37466-C03-03); Generalitat Valenciana (PROME-TEOII/2014/005) and the Universitat Politecnica de Valencia (PAID-02-11).

Conventional extraction techniques for plant phenolics are usually associated with high organic solvent consumption and long extraction times. In order to establish an environmentally friendly extraction method for grape skin phenolics, deep eutectic solvents (DES) as a green alternative to conventional solvents coupled with highly efficient microwave- assisted and ultrasound-assisted extraction methods (MAE and UAE, respectively) have been considered. Initially, screening of five different DES for proposed extraction was performed and choline chloride-based DES containing oxalic acid as a hydrogen bond donor with 25% of water was selected as the most promising one, resulting in more effective extraction of grape skin phenolic compounds compared to conventional solvents. Additionally, in our study, UAE proved to be the best extraction method with extraction efficiency superior to both MAE and conventional extraction method. The knowledge acquired in this study will contribute to further DES implementation in extraction of biologically active compounds from various plant sources.

Polifenoli predstavljaju skupinu spojeva biljnog podrijetla, čiju strukturu čini jedan ili više aromatskih prstena s jednom ili više hidroksilnih skupina. Uobičajena su sastavnica ljudske prehrane te se u različitim količinama nalaze u voću, povrću, vinu, voćnim sokovima, čaju i kavi. Polifenoli se u crnom grožđu nalaze u kožici, sjemenki i mesu. Sastav i količina pojedinih polifenola ovisi o sorti grožđa, klimatskim uvjetima, postupcima uzgoja vinove loze. Cilj ovog rada je optimizacija uvjeta za ekstrakciju polifenola iz kožice grožđa metodom raspršenjem matice uzorka kroz čvrstu fazu (MSPD). Cilj optimizacije metode je pronaći optimalne čimbenike za ekstrakciju, a to su udio organske faze, volumen ekstrakcijskog otapala, omjer mase sorbensa i mase uzorka, optimalni sorbens i ekstracijsko otapalo. Ekstrakti su analizirani tekućinskom kromatografijom visoke djelotvornosti s detektorom s nizom dioda i fluorescentnim detektorom. Najbolji rezultat za ekstrakciju polifenola iz kožice grožđa dobiven je s fenilsilicijevim dioksidom kao MSPD sorbensom s 10 mL smjese otapala acetonitril:voda=50:50 kao ekstrakcijskim otapalom. Najbolji omjer mase uzorak/sorbens pokazao se omjer 125 mg uzorka/375 mg sorbensa. Polyphenols are organic compounds, which structure makes one or more aromatic rings with one or more hydroxyl groups. Polyphenols colud be find in food especially fruits, vegetables, wine, fruit juices, tea and coffee. In red grapes we can find polyphenols in grape skin, seeds and pulp. The composition and quantity of particular polyphenols depends on grape cultivar, climatic conditions, methods of grapevine growing. The aim of this work is optimization conditions for extraction of polyphenolic compounds from grape skin by matrix solid-phase dispersion (MSPD). Parameters which were optimized are percent of organic eluation solvent, volume of eluation solvent, ratio of mass sample/sorbent, sorbent and the eluation solvent. The extracts were analyzed by high-performance liquid chromatography with diode array detector (HPLC-DAD) and fluorescence detector (HPLC-FLD). The best results for extraction of polyphenolic compounds from grape skin are obtained with Phenyl as an MSPD sorbent with 10 mL of acetonitrile:water=50:50 as an elution solvent. The best ratio of mass sample/sorbent is 125 mg sample/375 mg sorbent.

BACKGROUND Clinical evidence supports the relationship between carbonyl stress and type II diabetes and its related pathologies. Methylglyoxal (MGO) is the major dicarbonyl compound involved in carbonyl stress. Efforts are therefore being made to find dietary compounds from natural sources that could exert an MGO trapping response. RESULTS The in vitro MGO trapping capacity of six red and seven white grape skin extracts (GSE) obtained from winemaking by-products was investigated. Methanolic GSE exhibited a promising MGO trapping capacity that was higher in red GSE (IC50 2.8 mg mL−1) when compared with white GSE (IC50 3.2 mg mL−1). The trapping ability for red GSE correlated significantly with total phenolic content and antioxidant capacity. However, no correlations were observed for white GSE, which suggests that other compounds were involved in the trapping activity. CONCLUSION GSE may be considered a natural source of carbonyl stress inhibitors, thus opening up its possible utilization as a nutraceutical ingredient. Further investigations are required to understand the mechanism involved in the carbonyl trapping ability of red and white grape skin samples and their relationship with glycation. © 2015 Society of Chemical Industry., PSC Sri Harsha would like to thank the University of Milan for providing additional funding through the ERASMUS student network program. This work was partly funded by projects CSIC-201370E027, AGER (project number 2010–2222) and S2013/ABI-3028-AVANSECAL.

Microwave-assisted extraction (MAE) was investigated for recovering of total phenolic compounds from dried waste grape skins using a domestic microwave oven. Influence of vessel geometry, irradiation cycles, irradiation power and time was investigated. The results in terms of phenolics yield, antioxidant capacity and energy consumption were compared with a reference solid–liquid extraction (SLE) carried out for 2 h at 60°C. Equivalent yield of total phenolics as in SLE was achieved with a MAE extraction time of 1,033 sec (corresponding to 83 sec of irradiation at 900 W, 83% saving in extraction time compared to SLE and with a 70% energetic efficiency). Pre-maceration of samples and solvent pre-heating are proposed for large-scale industrial processes to enhance phenolics extraction and process efficiency.

We analyzed the relation between the assessment of grape berry skin thickness by means of histology sections and instrumental mechanical properties measurements. Berry skin of Vitis vinifera L. cultivar Corvina vineyards from Valpolicella Valpantena zone (Verona, Italy) were tested, evidencing a strong correlation between the two thickness determination methods. The middle or equatorial berry skin portion was found to be the less variable in instrumental skin thickness determination. In addition, unlike other studies, no correlation between the skin thickness and cell layers number was found.

Anthocyanins are large group of water soluble plant pigments responsible for the red, purple, and blue colours of many fruits, vegetables, flowers and grains. Chemically they are subdivided into the sugar-free anthocyanidine aglycons and the anthocyanin glycosides. In nature, there are 6 common anthocyanidins: pelargonidin, cyanidin, peonidin, delphinidin, petunidin, and malvidin. The colour of anthocyanins depends on their structure which can vary by glycosidic substitution at the positions 3 and 5 on the rings A and C as well as by acylation of the sugar groups with organic acids. Anthocyanins are responsible for the colour of red grapes and wine, so different authors have used their profile to classify the grape cultivars and wine authenticity. Thereby, the aim of this study was to investigate the profile of anthocyanidins (malvidin, delphinidin, cyanidin, pelargonidin and peonidin) in grape skin extracts of autochthonous Dalmatian cultivars: Babica, Ljutun and Crljenak. The extracts of anthocyanins were acid-hydrolyzed to release the corresponding anthocyanidins that were analysed by HPLC. HPLC analysis of the acid hydrolysis products of the grape berry skin extracts showed malvidin to be the major anthocyanidin in all extracts (ranged from 52 to 60%). Extract of Ljutun contained also high amounts of delphinidin (22%) while the lowest amounts of peonidin (from 5 to 6%) were found in all extracts. Obtained results on anthocyanidin profile of investigated grape skin extracts could be useful in chemotaxonomy for classifying red grape cultivars and wines.

Within 'green economy' approach, growing area of research in the development of green technologies is devoted to designing new, more environmentally friendly solvents. As a promising alternative to traditional organic solvents deep eutectic solvents (DESs) have been dramatically expanding in popularity over the past decade as a new generation of designer solvents with possible applications in various industrial fields. Since deep eutectic solvents consist of simple, cheap, and naturally occurring compounds with a high safety profile, they may be used for highly efficient extraction as replacement for harmful and volatile organic solvents and storage of natural products from plants. Additionally, the components of DESs are abundant in our daily diet and extract may directly be used in food, pharmaceutical, cosmetical and agrochemical applications without need for expensive downstream purification steps. Herein, we are going to present evaluation of DESs in extraction of plant phenolic from a grape skin as one of the world’s largest fruit crops. After selection of the most suitable DESs, optimization of extraction is carried out and the parameters that influence the extraction process such as temperature, time, water addition and solid/liquid ratio, are studied. Obtained data will serve for filling gaps for a using green solvent such DESs as promising green technology for the extraction of various natural products from plant material.

In this study free and bound volatile compounds of Aglianico and Uva di Troia grape skins and pulp juices were extracted and concentrated by Solid Phase Extraction (SPE) technique. 26 grape aroma compounds were monitored and quantified by gas chromatography–mass spectrometry (GC-MS) in selective ion monitoring modality (SIM). Aglianico showed a higher total level of free and bound volatile fraction than Uva di Troia grapes. The aroma of the two red grape varieties was carried out by grouping volatile compounds into seven aromatic series. The free volatile fraction of the two grape varieties was essentially dominated by herbaceous and floral series. The herbaceous series does not differentiate the two grape varieties, while the floral series is two times higher in Uva di Troia grape skin than in Aglianico. The bound volatile fraction, representing aroma potential of the two grape cultivars, differentiated them. Aglianico grapes were characterized mainly by fruity and sweet and were not characterized by spicy and toasty series. On the contrary, spicy series result enough importance in Uva di Troia grapes' aroma profile.

In this study seven published methods of extraction of skin free and bound volatile compounds have been compared. The free and bound volatiles were separated by solid phase extraction (SPE) and then analysed by gas chromatography coupled with mass spectrometry (GC–MS). The results showed that the extraction of volatile compounds from grapes is highly affected by extraction solution features. The solution at pH 3.2 and 0% ethanol resulted the most effective as it led to the extraction of a higher number and amount of free and glycosilated volatile compounds. The selected extraction method of grape skin and the process of pulp juice were validated for quantitative determination of a wide range of grape aroma compounds. A total of 37 free and bound grape aroma compounds were quantified by GC–MS in selective ion monitoring modality (SIM). Among them, 26 volatile compounds resulted validated in grape skin and pulp juice.

Un résumé en français de cet article a été publié dans Techniloire.com; International audience; BACKGROUND: Several studies have investigated the composition of phenolics in grape skin during grape maturation under various conditions of light exposure, water stress, nitrogen supply and mineral nutrition, but their localisation during berry development is not well known. In this study the composition and localisation of proanthocyanidins were monitored for three years on four plots known to induce a distinctive behaviour of the vine (Cabernet Franc). The composition of phenolics was determined by spectrophotometry; also, in one year, proanthocyanidins were determined by high-performance liquid chromatography. Further information was obtained histochemically by means of toluidine blue O staining and image analysis. RESULTS: The results indicated that clear differences in phenolic quantification existed between the biochemical and histochemical approaches; the proportion of cells without phenolics was not linked with the quantity determined by the analytical methods used. The histochemical method showed the evolution of the localisation and typology of cells with and without phenolics during ripening. The number of cells without any phenolic compounds appeared to be very dependent on the mesoclimatic conditions and only slightly dependent on the site water status. CONCLUSION: Clear differences in phenolic quantification existed between the biochemical and histochemical approaches; the proportion of cells with phenolics was not linked with the quantity determined by biochemistry. The histochemical method showed an evolution of the localisation and typology of cells with and without phenolics in which mesoclimatic conditions were the most influential factor. Finally, the study showed some advantages of the histochemical approach: it gives information about the anatomy of the tissue as well as the nature and distribution of some of the large macromolecules and allows reconstruction of the three-dimensional plant structure

A spectrofluorimetric method based on the grape skin has been developed for the determination of Fe3+ at pH 5.0. The emission wavelength of the grape skin sensor occurs at 680 nm and the excitation wavelength at 421 nm. The fluorescence of sensor could be quenched by Fe3+ due to the complexing ability of anthocyanin with the metal ions. Anthocyanin, the main pigment in the grape skin, has been found fluorescence sensing material. The sensor based on the grape skin exhibited a calibration response for Fe3+ in two concentration ranges of 1.0 × 10-8 - 1.0 × 10-5 M (r2 = 0.9888) and 3.2 × 10-5 - 3.2 × 10-4 (r2 = 0.9856) M at 60 oC. The detection limit was found to be 7.5×10-9 M, and the other common ions did not interfere.

Polyphenols are of secondary plant metabolites, naturally present in fruit, vegetables and herbs. In last two decades the number of publications on the potential health benefits of these compounds has increased enormously. The aim of this study is to determine and compare polyphenolic profile and related antioxidative properties of Vitis vinifera leaf and grape berry skin extracts. The research includes 21 grape varieties (White: Bogdanuša, Debit, Grk, Kuč, Malvasija, Maraština, Medna, Prč, Pošip, Trebbiano toscano, Vugava and Žlahtina ; Red: Babica, Babić, Cabernet sauvignon, Dobričić, Glavinuša, Ninčuša, Plavac mali, Plavina and Vranac). Plant material was collected at the stage of the grape technological maturity. Phenolic profile of plant extracts (total phenols, flavonoids, non-flavonoids, catechins and flavanols) were determined using spectrophotometric methods. Antioxidant capacity of plant extracts was estimated by Ferric Reducing/Antioxidant Power (FRAP) assay. The research of polyphenolic profile of berry skin and grape leaves extracts has shown difference in the mass amounts of total phenols among selected grape cultivars, as expected. The high antioxidant capacity of tested extracts has been observed and related to the presence of a mixture of polyphenolic compounds with good antioxidant properties. Significant linear correlation between total phenol content, or main phenolic subgroups, and FRAP was confirmed. To make practical comparison of relative antioxidant potential of phenolics extracted from berry skins and grape leaves, the phenol antioxidant coefficient (PAC) was calculated for each extract. PAC values ranged from 4.54-13.05 for grape skin extracts, and from 8.42-12.13 for grape leaves extracts. It can be concluded that grape skin extracts, as well as leaves extracts, can be a good source of phenolics with good antioxidant properties.

Correspondance auteur: Doco T. E-mail: doco@supagro.inra.fr; International audience; Polysaccharide modification is the most fundamental factor that affects firmness of fruit during ripening. In grape, because of the lack of information on the modifications occurring in cell wall polysaccharides in skins, but also because this tissue contains large amounts of organoleptic compounds for winemaking, a study was performed on the evolution and extractability of polysaccharides from grape skins of Shiraz cultivar throughout ripening, A HEPES/phenol extraction technique was used to analyze Shiraz grape cell wall material isolated from skins of berries harvested from one to ten weeks after veraison. Total amounts in cell wall polysaccharides remained constant during ripening (4.2 mg/berry). A slight decrease in galactose content of insoluble polysaccharides was observed, as well as a significant de-esterification of methoxylated uronic acids, indicating that some modifications occur in cell wall polysaccharides. The water-soluble fraction represented a very small fraction of the whole polysaccharides, but its amounts increased more than 2-fold between the first and the last sample. Isolated cell walls were also analyzed for their protein composition. Last, hydroalcoholic extractions in model-wine solution were also performed on fresh skins. This extracted fraction was very similar to the water-soluble one, and increased during the entire period. By comparison with polysaccharide modifications described in flesh cell wall in previous works, it can be assumed that the moderate skin polysaccharide degradation highlights the protective role of that tissue

Mestrado em Engenharia Agronómica - Hortofruticultura e Viticultura - Instituto Superior de Agronomia The plants respond to oxidative stress with the activation of defensive antioxidants mechanisms, which come up as an integrative part of the drought stress tolerance strategies. With this work it was attempted to evaluate oxidative stress caused by three different irrigation treatments – NI (non irrigated), RDI (Regulated Deficit Irrigation) and FI (Full Irrigation) – in the skin of Vitis vinifera L. cv ‘Trincadeira’ grapes, throughout ripening process. The activity of guaiacol peroxidase (POD), poliphenol oxidase (PPO), ascorbate peroxidase (APX), glutathione reductase (GR) and catalase (CAT) was determined on different stages of ripening. Higher levels of drought stress were found in NI treatment, with the highest average levels of POD activity, and have originated possibly a major incidence of oxidative stress, followed by RDI and FI treatments, where the level of drought stress was respectively minor. Water availability seems to affect the plant’s response to the accumulation of ROS on the different stages of ripening, showing a more efficient response on the final stage in NI treatment and on vérasion on RDI and FI treatments, which may indicate a higher investment of the plant on the final stage of the reproductive cycle under limited water availability.