Effects of Extraction Solvent Mixtures on Antioxidant Activity Evaluation and Their Extraction Capacity and Selectivity for Free Phenolic Compounds in Barley (HordeumvulgareL.)

Abstract

Four kinds of solvent extracts from three Chinese barley varieties (Ken-3, KA4B, and Gan-3) were used to examine the effects of extraction solvent mixtures on antioxidant activity evaluation and their extraction capacity and selectivity for free phenolic compounds in barley through free radical scavenging activity, reducing power and metal chelating activity, and individual and total phenolic contents. Results showed that extraction solvent mixtures had significant impacts on antioxidant activity estimation, as well as different extraction capacity and selectivity for free phenolic compounds in barley. The highest DPPH* and ABTS*+ scavenging activities and reducing power were found in 80% acetone extracts, whereas the strongest *OH scavenging activity, O2*- scavenging activity, and metal chelating activity were found in 80% ethanol, 80% methanol, and water extracts, respectively. Additionally, 80% acetone showed the highest extraction capacity for (+)-catechin and ferulic, caffeic, vanillic, and p-coumaric acids, 80% methanol for (-)-epicatechin and syringic acid, and water for protocatechuic and gallic acids. Furthermore, correlations analysis revealed that TPC, reducing power, DPPH* and ABTS*+ scavenging activities were well positively correlated with each other (p < 0.01). Thus, for routine screening of barley varieties with higher antioxidant activity, 80% acetone was recommended to extract free phenolic compounds from barley. DPPH* scavenging activity and ABTS*+ scavenging activity or reducing power could be used to assess barley antioxidant activity.

DNA scission inhibition, antioxidant, and antiproliferative activities of water chestnut (Trapa natans) extracted in different solvents

“…Our results indicate that aqueous extracts had the best impact on these antioxidant activities. These findings are partially in agreement with those of Zhao et al (2006), who found water as an efficient solvent for reducing power evaluation. These observations suggested that solvent polarity and nature of the plant phenols greatly influence the antioxidant extraction.…”

Comparison of Antioxidant Activity of Barley (Hordeum vulgare L.) and Malt Extracts with the Content of Free Phenolic Compounds Measured by High Performance Liquid Chromatography Coupled with CoulArray Detector

“…Additional analytical data of barley and malt analysis (Žabčice). as for malt (n = 60, r ranged from 0.624 to 0.867, p < 0.01), which is in agreement with the data already published 11,29 . Additional analytical data of selected barley and malt samples are summarized in Table IV.…”

“…Several types of polyphenol extraction have been described 6,7,11,19,22,23,26,29 . The mixture of water with organic solvent is one of the most used.…”

Phytochemical evaluation and in vitro antioxidant and photo-protective capacity of Calendula officinalis L. leaves

“…• ) Assessment of the ability to scavenge free radicals in relation to the superoxide radical is based on the generation of radical O 2 -• throughout the system by enzymatic reaction, catalyzed by the enzyme hypoxanthine xanthine oxidase (Zhao et al 2006). A sample (100 µL) was added to the reaction solution containing 100 µL of 30 mM disodium ethylenediaminetetraacetic acid (EDTA), 100 µL of 3 mM hypoxanthine (HPX), and 200 µL of 1.42 mM nitrotetrazolium blue chloride (NBT).…”

“…• ) The antiradical activity studies of samples and analytical standards with the hydroxyl radical at different concentrations were performed using the 2-deoxy-D-ribose method proposed by Zhao et al (2006) with some modifications. The FeCl 3 • 6H 2 O and ascorbic acid were prepared in milli-Q water before use.…”