Phenolic compounds and antioxidant activities of grape canes extracts from vineyards

Abstract

matic, and natural or synthetic sources (Nardini et al., 2005). Natural phenolics possess strong antioxidant properties that enable them to donate hydrogen, scavenge free radicals, break radical chain reactions, chelate metal ions, and quench singlet oxygen in vitro and in vivo (Rice-Evan et al., 1996).Previous studies have revealed that one-third of all cancer cases and one-half of cardiovascular diseases RESEARCH ARTICLE OPEN ACCESS AbstractGrape canes are the main agro-wastes from vineyards. This work studied the antioxidant activities of the defatted methanolic extracts (ME) of canes from 11 genotypes: 5 Vitis vinifera widely known cultivars and 6 Chinese wild varieties from three species (V. amurensis, V. davidii, and V. pentagona) and the antioxidant activities of the ME's chloroform fractions (CF), ethyl acetate fractions (EAF) and water fractions (WF). Among ME and its three fractions, EAF's total phenolic contents (TPC) and total flavonoid contents (TFC) were the highest, at 586 mg/g of gallic acid equivalent and 320 mg/g of quercetin equivalent, respectively. The antioxidant power of the fractions/extracts was in the order EAF > ME > WF > CF, based on the DPPH radical-scavenging power and ferric-reducing antioxidant activity, while the order was EAF > CF > WF >ME based on the β-carotene-linoleic acid bleaching activity. Methanolic extracts demonstrated the strongest Fe 2+ -chelating activity. The antioxidant activities of the extracts/fractions generally correlated with the TPC and TFC in all assays, except with the Fe 2+ -chelating test. Grape canes from V. davidii had the highest TPC, TFC and antioxidant activities compared with those from other grape species. Catechin, epicatechin and trans-resveratrol were the predominant phenolic components of fractions/extracts. In light of these valuable bioactivities, grape canes from annual pruning practice considered as waste material have good commercial potential for utilization as a promising natural antioxidant in the food, pharmaceutical and cosmetic industries, given its low cost and availability in large amounts.Additional key words: vineyard; flavonoids; antiradical effect; agro-wastes. Abbreviations used: AA (antioxidant activity); CAT (catechin); CF (chloroform fractions); DAD (photodiode array detector); DPPH (2, 2-diphenyl-1-picrylhydrazyl); DW (dry weight); EAF (ethyl acetate fractions); EC (epicatechin); FRAP (ferric reducing antioxidant power); GA (gallic acid); GAE (gallic acid equivalent); ME (methanolic extracts); PA (protocatechuic acid); QE (quercetin equivalent); RES (trans-resveratrol); SYA (syringic acid); TBHQ (tert-butylhydroquinone); TE (Trolox equivalent); TFC (total flavonoids contents); TPC (total phenolic contents); TPTZ (2,4,6-tri-(2-pyridyl)-s-triazine); VA (vanillic acid); WF (water fractions).

Physical-Chemical Evaluation of Active Food Packaging Material Based on Thermoplastic Starch Loaded with Grape cane Extract

“…The radical-scavenger capacity ranged from 15 (TPS/WE5) to 39% (TPS/WE15) using water as a solvent, from 38 to 87 in methanol/water 80/20 v/v, and from 31 to 86% in absolute methanol, for 1000 µL of DPPH solution. High antioxidant capacity of obtained grape cane extract has been already proven in our previous paper [26] and supported in the literature by other authors [45,46], due to the presence of phenolic groups in extract itself. The IC 50 (concentration required to scavenge 50% DPPH radicals) values of the oligostillbenes caraphenol A and α-viniferin A were determined and compared with Trolox antioxidant standard by Li et al [47].…”

Color, anthocyanin, and antioxidant characteristics of young wines produced from spine grapes (Vitis davidii Foex) in China

“…ABTS radical scavenging activity of the wine sample was performed according to the published methods with minor modifications [ 15 , 32 ]. Briefly, 7 mM ABTS solution was mixed with 140 mM potassium persulfate aqueous solution to generate ABTS radical cation.…”

“…Phenolic compounds have been reported to have capacity of scavenging free radicals, donating hydrogen, chelating metal ions, breaking radical chain reaction, and quenching singlet oxygen [ 15 ]. It has been also suggested that phenolic compounds could enhance the endogenous antioxidant capacity of cells/tissues and interact with cellular receptors and/or enzymes, which could improve human health [ 16 ].…”

“…It has been also suggested that phenolic compounds could enhance the endogenous antioxidant capacity of cells/tissues and interact with cellular receptors and/or enzymes, which could improve human health [ 16 ]. There are many in vitro methods that have been used to determine the antioxidant properties of phenolic compounds [ 15 , 17 , 18 ]. For example, 2,2ʹ-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) are two free radicals that can be scavenged with the presence of antioxidants, and therefore ABTS and DPPH assays can estimate antioxidant capacity of phenolic compounds [ 17 , 18 ].…”

“…Antioxidants in cupric reducing antioxidant capacity (CUPRAC) assay can convert neocuproine/copper (II) complex to neocuproine/copper (I) complex, which results in a change on the complex absorption characteristics [ 19 ]. It has been confirmed that antioxidant features of phenolic compounds in wine are mainly depended on its variety, origin and vintage [ 15 , 20 , 21 ].…”