Multi-experimental Characterization of Grape Skin Extracts

Journal of Functional Foods, 2013

The phenolic composition and antiox idant act ivity of musts and skin extracts from Tempranillo grapes dried for varia ble lengths of times wer e examined here . Both wer e found to increase in the grape must with increasing drying time, but the opposite trend was observed in the skin extracts. The antioxidant activity of the must and skin was lar gely due to anthoc yanins. Also, the anthocy anins fraction exhibited the highest antioxidant activity per gram of phenolic compound in the musts and skin extracts at the end of the drying process, polymeric pigments and high-molecu lar -weight proc yanidins wer e also prominent in this respect. In vivo antiox idant activity in terms of protein oxidation and surviv al of Sacc harom yces cerevisiae cells pre viously incubated with 10 lg/mL of polyphenols from the musts and skins and exposed to hydroge n peroxide was also measured. Both extracts exerted a protecti ve effect against oxidativ e stress, the effect increasing with increasing deh ydration time and being some what higher for skin than for must. Thus, must and skin from dehy drated gr apes possess antioxidant properties, which allo w the latter , a by-product of sweet wine, to be used as a natural source of antiox idants.

Fitoterapia, 2017

The antioxidant potential of grape (Vitis vinífera L.) stems has been reported in the last decade although no identification of the individual compounds responsible for such action has been done. In this work, polyphenolic extract of grape stems was processed resorting to semi-preparative HPLC, allowing to obtain 5 purified polyphenols (caftaric acid, malvidin-3-O-glucoside, quercetin-3-O-glucuronide, mailvidin-3-O-(6-O-caffeoyl)-glucoside, and Σ-viniferin), which were fully characterized by HPLC-PDA-ESI-MS(n). Isolated compounds were featured on their radical scavenging capacity (DPPH and ABTS), cell viability, anti-inflammatory activity, and capacity to modulate the level of reactive oxygen species, glutathione, lipid peroxidation, and overall oxidative stress in a biological model (human keratinocytes) in vitro, under basal and oxidative conditions. The results obtained noticed the combinations malvidin-3-O-glucoside+Vitamin E and quercetin-3-O-glucuronide+vitamin C as the most e...

2013

The purpose of this study was to determine the antioxidant activity of organic apple and red grapes fruit (pulp, peel, seed and juice). The content of total phenolics in the extracts was determined spectrometrically according to the Folin -Ciocalteu method and calculated as gallic acid equivalents (mg GAE/100g). Antiradical activities of the extracts were evaluated by a microassay using 1,1¢diphenyl-2-picrylhydrazyl, spectrophotometrically method. Juice was obtained by crushing fruit in a laboratory press. The paper presents the possibility of improving the antioxidant activity of apple juice and grape seeds by extraction of polyphenolic compounds in the residue left after pressing fruit and added to apple juice.In terms of content in polyphenols, is very important to note that the value of grapes grow from 285.2 mg GAE/100g fruit to 385.2 mg GAE/100g in the juice . It was shown that the content of total antioxidant activity in juices varied up to 1.14 red grape juices up to 1.025 a...

Visão Acadêmica, 2019

The analysis of antioxidant potential activity, from skins and seeds of the species Vitis vinifera cv. Tannat and Vitis labrusca cv. Bordeaux, obtained after the first stage of fermentation of their respective wines, performed from crude ethanol extract. Dried skins and seeds of the species Vitis vinifera cv. Tannat and Vitis labrusca cv. Bordeaux, obtained after the first stage of fermentation of their respective wines, were analyzed for antioxidant potential. For that, a crude ethanol extract was made. First, a HPLC: Liquid Chromatography High Efficiency method was developed for detection and confirmation of the presence of the compounds responsible for antioxidant potential in grapes. The antioxidant potential was verified using three types of tests: DPPH (2,2-diphenyl-1-picrylhydrazyl), phosphomolybdenum complex, and lipid peroxidation (TBARs-thiobarbituric acid). The results showed that even though there is an extraction of phenolic compounds during alcoholic fermentation, the remaining material still possesses various phenolic compounds that maintain their antioxidant characteristics. Antioxidation capabilities were more active with DPPH, then in lipid peroxidation, and the lowest result concerning the standards analyzed with phosphomolybdenum method. Statistical analysis showed no significant difference at the 5% level between the two varieties studied. These results show the presence of compounds with antioxidant activity in the waste from winemaking and for this reason, the analyzed material is promising for use in various pharmaceutical fields such as medicines, cosmetic and food technology. The present study aimed to clarify the existence of antioxidative properties in the wine waste thus adding value to the residue.

Indian Journal of Clinical Biochemistry, 2014

Grapes are the richest source of antioxidants due to the presence of potent bioactive phytochemicals. In this study, the phytochemical contents, scavenging activities and protective role against H 2 O 2-induced oxidative stress in liver tissue ex vivo of four grape (Vitis vinifera) cultivars extracts, namely Flame seedless (black), Kishmish chorni (black with reddish brown), Red globe (red) and Thompson seedless mutant (green), were evaluated. The total phenolics and flavonoids content in pulp or skin fractions of different grape cultivars were in the range of 47.6-310 mg gallic acid equivalent/g fresh weight (fw), and 46.6-733.3 lg catechin equivalent/g fw respectively. The scavenging activities in skin of different grape varieties against 2,2-diphenyl-1picrylhydrazyl (44-58 %), hydrogen peroxide (15.3-18.6 %), and hydroxyl radicals (50-85 %), were higher than pulp of the corresponding cultivars. These scavenging activities of grape extracts were found to be significantly (p \ 0.01) correlated with the levels of total phenols, flavonoids and ascorbic acid. Liver tissues from goat treated with H 2 O 2 (500 lM) showed significantly decreased GSH content by 42.9 % and activities of catalase by 50 % and glutathione reductase by 66.6 %; while increased thiobarbituric acid reactive substances and nitric oxide level by 2.53-and 0.86-fold, respectively, and activity of glutathione S-transferase by 0.96-fold. Grape skin extracts showed the stronger protective activity against H 2 O 2-induced oxidative stress in liver tissue ex vivo, than its pulp of any cultivar; and the Flame seedless (black) cultivar showed the highest potential. In conclusion, our study suggested that the higher antioxidant potential, phytochemical contents and significant scavenging capacities in pulp and skin of grape extracts showed the protective action of grape extracts against H 2 O 2-induced oxidative stress in liver tissue ex vivo.

2017

Wine grape pomace (WGP), is a valuable by-product from the winemaking industries, recognized due to its relevant polyphenolic compounds. This study investigated the potentials of wine waste in Ethiopia from red wine grape pomaces(RWGP)and white wine grape pomaces (WWGP) (Vitisvinifera L.) for extraction of antioxidants. The effect of solvent ratio, extraction time and temperature on the yield of RWGP and WWGP extract was also studied. The experimental design was employed using the Design Expert 6.0.8, three-level-three factor Central Composite Design in triplicates at the center point in the optimization study, requiring 17 experiments. The results showed that minimum and maximum extract yields were 30.23% and 52.35% for RWGP, and 20.97% and 48.56% for WWGP, respectively. Solvent ratio, extraction time and Temperature had a significant (p < 0.05) effect on the extract yields. The statistical analysis indicates that, the linear terms of solvent ratio, extraction time and temperature, had positive effect on response yield. The quadratic terms (pure quadratic terms) negatively affected the extraction yield and only AB interaction for both RWGP extract and WWGP extract had negative influence. Characterization of antioxidants was carried through the evaluation of total phenolic content (TPC), total flavonoid (TF), total anthocyanin content and scavenging capacity against 1,1-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity performed using spectrophotometer. Additionally, food applications of the obtained extract to inhibit oil oxidation were carried out according to the Shaal Oven Test compared with butylated hydroxytoluene (BHT) by measuring per oxide value (PV). Results obtained under optimum conditions were: total phenolic content 15.

Molecules, 2011

Total phenolic contents (TPC), total flavonoid contents (TFC), related antioxidative and antiradical capabilities of grape cane extracts from 11 varieties (five V. vinifera cultivars and six Chinese wild grapes) widely grown in China were evaluated. Antioxidant properties were determined as DPPH and ABTS radical-scavenging abilities, superoxide anion and hydroxyl radical and hydrogen peroxide scavenging assays, as well as reducing power. Phenolic profiles of the extracts were characterized by using high-performance liquid chromatography (HPLC) techniques. All extracts exhibited strong antioxidant and effective free radical inhibition activities (EC 50 values), which generally correlated negatively with TPC (r = −0.804 to −0.918) and TFC (r = −0.749 to −0.888). In comparison with gallic acid, Trolox and tert-butylhydroquinone (positive controls), most grape cane extracts showed more efficient scavenging effects toward different reactive oxygen species. HPLC analysis revealed the presence of (+)-catechin, (−)epicatechin, and trans-resveratrol as major phenolic components in the extracts. These results suggest that grape cane extracts may serve as a potential source of natural antioxidant for food and pharmaceutical application.

Bioresources, 2019

The antioxidant activity and the tocopherol and polyphenol contents of organic grapevines residue were analyzed after Soxhlet extraction of grape seeds and skin with ethanol and petroleum ether. The highest antioxidant activity was determined for the ethanol extract of the seeds and was 58.65 μM Trolox/mg, which was four times higher than for the ethanol extract of the skin at 14.24 μM Trolox/mg. It was comparable to that of the alpha-tocopherol (62.28 μM Trolox/mg) and butylated hydroxyanizol (69.55 μM Trolox/mg). A concentration of 29.5 μg/mL ethanol seed extract was needed to decrease the initial DPPH radical concentration by 50%. The high antioxidant activity was because of the high tocopherol (402.28 mg/kg) and total phenols contents (113.7 gallic acid equivalent (g/kg)) in the seeds. The dominant polyphenol in the ethanol seed extract was coumaric acid (10.97 g/kg). The dominant polyphenols in the ethanol skin extracts were rutin (6.79 g/kg), quercetin (3.75 g/kg), and catechin (3.99 g/kg), which can be used in functional foods to reduce risk factors for several human diseases.

The British journal of nutrition, 2000

Epidemiological studies indicate that moderate alcohol consumption, particularly wine, reduce the risk of CHD. The present study was designed to investigate the effect of grape-skin extract on markers of oxidative status. The study was designed as a randomised crossover. A diet with a low content of flavonoids was served with strict control of intake in two consecutive 1-week intervention periods to fifteen subjects (nine women, six men) divided randomly into two groups. During one of the weeks the subjects from either group consumed 200 ml grape-skin extract in water (1 mg extract/ml) at each of three daily meals (31.3 mg total phenolics, including 9.0 mg catechin). An increased activity of glutathione reductase and a borderline increase of glutathione peroxidase activity in erythrocytes were observed after grape-skin intervention, while the intervention had no significant effect on superoxide dismutase or catalase. Likewise, no effect was found on 2-aminoadipic semialdehyde (AAS) ...

Acta periodica technologica, 2009

Composition and antioxidant activity of grape seed extract (GSE) obtained from red grape varietes are very well documented, in contrast to the white varietes. This paper presents the results of polyphenols content of ethyl acetate extract of grape seeds, obtained from two white grape varieties, Italian Riesling and Župljanka, and their antioxidant activity on the stable DPPH radical. The influence of the addition of GSE to raspberry juice on the DPPH radical was also examined. Content of total polyphenols in GSEs ranged between 81.6 and 82.8% (w/w), and the contetn of flavan-3-ols between 66.2 and 91.0% (w/w). HPLC results showed that the most abundant components in the extract were (+)-catechin and (-)-epicatechin for both grape varieties. All tested GSEs exhibited good antioxidant activity. IC 50 values for the GSEs of Italian Riesling and Župljanka were 0.79 and 0.95 mg sample/mg DPPH radical, respectivelly. Since the GSE of Italian Riesling possesed stronger antioxidant activity, it was used for further experiments. The IC 50 value for raspberry juice was 4.18 mg raspberry juice/mg DPPH. The raspberry juice with addition of 0.60 µg/mL of GSE showed antioxidant activity of 39.2%. The same juice with the threefold concentration of vitamin C (1.81 µg/ml) exhibited similar antioxidant activity (33.9%). Antioxidant activity of the same amount of juice without added antioxidants was lower (15.7%). The results showed that the GSE of white varietes could be considered as a good functional food ingredient.