Showing papers on "DPPH published in 2011"
TL;DR: A critical review on various developments to the DPPH method is presented, which has undergone various modifications to suit the requirements, even though the basic approach remains same in all of them.
Abstract: α, α-diphenyl-β-picrylhydrazyl (DPPH) free radical scavenging method offers the first approach for evaluating the antioxidant potential of a compound, an extract or other biological sources. This is the simplest method, wherein the prospective compound or extract is mixed with DPPH solution and absorbance is recorded after a defined period. However, with the advancement and sophistication in instrumental techniques, the method has undergone various modifications to suit the requirements, even though the basic approach remains same in all of them. This article presents a critical review on various developments to the DPPH method.
1,290 citations
TL;DR: In this paper, the 50 most popular antioxidant-rich fruits, vegetables and beverages in the US diet were identified and analyzed for their antioxidant capacities, total phenolics and flavonoids content.
1,131 citations
TL;DR: In this article, the authors analyzed the total antioxidant capacity of 23 commercially available vegetable juices and determined the stability of the antioxidant capacity following an in vitro digestion procedure using the same methods.
478 citations
TL;DR: In this article, the authors evaluated the antioxidant activity of carotenes and xanthophylls measured by various methods, compared to α-tocopherol, BHA and BHT.
472 citations
TL;DR: In this article, the authors compared contents of phenolics, vitamin C, anthocyanin and antioxidant activity of 11 fresh exotic fruits, such as murici and mangaba, using two antioxidant systems 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), expressed as TEAC (Trolox Equivalent Antioxidant Capacity) and VCEAC (Vitamin C
412 citations
TL;DR: In this article, the authors presented comprehensive data on TPC, reducing power, and antioxidant activity for the six fruit residues examined in this study, and demonstrated that these residues can serve as potential sources of antioxidants for use in food and pharmaceutical industry.
361 citations
TL;DR: In this paper, Lyophilised soluble coffees extracted by various methods from light, medium and dark-roasted arabica and robusta beans were evaluated for antioxidant activity (AA) using ABTS, Folin, DPPH and FRAP techniques.
307 citations
TL;DR: A positive linear correlation between antioxidant activity and the total phenolics and flavonoid contents indicates that these compounds are likely to be the main antioxidants contributing to the observed activities.
Abstract: The antioxidant, anti-inflammatory, and cytotoxic activities of water and ethanol extracts of 14 Chinese medicinal plants were investigated and also their total phenolics and flavonoid contents measured. The antioxidant activity was evaluated in a biological assay using Saccharomyces cerevisiae, whereas the radical scavenging activity was measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Total phenolics and flavonoid contents were estimated by Folin-Ciocalteu and aluminum chloride methods, respectively. The anti-inflammatory activities of the plant extracts were determined by measuring the inhibition of production of nitric oxide (NO) and TNF-α in LPS and IFN-γ activated RAW 264.7 macrophages. Their cytotoxic activities against macrophages were determined by Alamar Blue assay. Four plants, namely, Scutellaria baicalensis, Taxillus chinensis, Rheum officinale, and Sophora japonica, showed significant antioxidant activity in both yeast model and also free radical scavenging methods. The ethanol extract of S. japonica showed highest levels of phenolics and flavonoids (91.33 GAE mg/g and 151.86 QE mg/g, respectively). A positive linear correlation between antioxidant activity and the total phenolics and flavonoid contents indicates that these compounds are likely to be the main antioxidants contributing to the observed activities. Five plant extracts (S. baicalensis, T. chinensis, S. japonica, Mahonia fortunei, and Sophora flavescens) exhibited significant anti-inflammatory activity by in vitro inhibition of the production of NO and TNF-α with low IC 50 values. These findings suggest that some of the medicinal herbs studied in this paper are good sources of antioxidants.
304 citations
TL;DR: In this paper, the authors evaluated the concentration of bioactive compounds in black currant berries ( Ribes nigrum L.) and their antioxidant activity after microencapsulation by spray-drying.
287 citations
TL;DR: Results of the present study indicate that sonication may be employed as a suitable technique for kasturi lime juice processing, where antioxidant and other bioactive compound retention or enhancement is desired, along with the achievement of safety and quality standards.
287 citations
TL;DR: In this article, the authors used high performance liquid chromatography (HPLC) and HPLC-tandem mass spectrometry (MSn) to identify 50 phenolic compounds belonging to several classes, namely, phenolic acids and their derivatives, dehydrodiferulates and dehydrotriferulates, flavan-3-ol monomers and dimers, flavonols, flavones and flavanonols in four phenolics fractions of several whole millet grains (kodo, finger (Ravi), finger (local), foxtail, proso, little
TL;DR: In this paper, the antioxidant potency and total phenolic and flavonoid contents of kiwifruit (Actinidia deliciosa) in vitro were determined by analyzing the radical scavenging activity of lyophilised water extract from kiwi.
01 Jan 2011
TL;DR: In this article, in vitro antioxidant activity, total phenolic content and concentration of flavonoids of five different extracts, from the whole herb of Marrubium peregrinum L. (Lamiaceae) were determined using spectrophotometric methods.
Abstract: In this study, in vitro antioxidant activity, total phenolic content and concentration of flavonoids of five different extracts, from the whole herb of Marrubium peregrinum L. (Lamiaceae) were determined using spectrophotometric methods. Antioxidant activity of extracts were expressed as percentage of DPPH radicals inhibition and IC50 values (μg/ml). Values in percentage ranged from 27.26 to 89.78%. The total phenolic content ranged from 27.26 to 89.78 mg/g of dry weight of extract, expressed as gallic acid equivalents. The total flavonoid concentrations varied from 18.72 to 54.77 mg/g, expressed as rutin equivalents. Methanolic exstract of M. peregrinum showed the highest phenolic and flavonoid concentration and strong antioxidant activity. The significant linear correlation was confirmed between the values for the total phenolic content and antioxidant activity of plant extracts. The high contents of phenolic compounds indicated that these compounds contribute to the antioxidant activity. The M. peregrinum can be regarded as promising candidates for natural plant sources of antioxidants with high value.
TL;DR: In this article, the physicochemical and nutritional characteristics of twenty selected exotic fruits and the influence of their physiologically active compounds on human health, through scientifically proven information, were described.
TL;DR: The total phenolic content and antioxidant potential of avocado phenolics was affected by the extracting solvent and avocado variety and the avocado materials also displayed moderate antimicrobial effects against Gram-positive bacteria.
Abstract: The first aim of the present work (study 1) was to analyze ethyl acetate, 70% acetone, and 70% methanol extracts of the peel, pulp, and seed from two avocado (Persea americana Mill.) varieties, namely, 'Hass' and 'Fuerte', for their phenolic composition and their in vitro antioxidant activity using the CUPRAC, DPPH, and ABTS assays. Their antimicrobial potential was also studied. Peels and seeds had higher amounts of phenolics and a more intense in vitro antioxidant potential than the pulp. Peels and seeds were rich in catechins, procyanidins, and hydroxycinnamic acids, whereas the pulp was particularly rich in hydroxybenzoic and hydroxycinnamic acids and procyanidins. The total phenolic content and antioxidant potential of avocado phenolics was affected by the extracting solvent and avocado variety. The avocado materials also displayed moderate antimicrobial effects against Gram-positive bacteria. Taking a step forward (study 2), extracts (70% acetone) from avocado peels and seeds were tested as inhibitors of oxidative reactions in meat patties. Avocado extracts protected meat lipids and proteins against oxidation with the effect on lipids being dependent on the avocado variety.
TL;DR: Pineapple has several beneficial properties including antioxidant activity. as discussed by the authors extracted the fruit of pineapple with ethyl acetate, methanol and water and determined the phenolic content of the extracts by Folin-Ciocalteu method and antioxidant activity was assayed through some in vitro models such as phosphomolybdenum, β-carotene-linoleate, and radical scavenging activity using α,α-diphenyl-β-picrylhydrazyl (DPPH) method.
TL;DR: In this paper, the phenolic compounds content and antioxidant activity of seed and skin of pomace from the vinification of grape varieties widely produced in Brazil were investigated with a view to their exploitation as a potential source of natural antioxidants.
TL;DR: The use of mid-infrared spectroscopy to predict the total antioxidant capacity of vegetables provides a rapid and precise alternative to traditional wet chemistry analysis.
TL;DR: In this article, the relationship between total phenolic and mineral contents with antioxidant activities of pulps and peels from eight banana (Musa sp.) cultivars were studied using Folin-Ciocalteu colorimetric method, and antioxidant activities were measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and ferric reducing antioxidant potential (FRAP) assay.
TL;DR: It is found that TFPL possesses potent antioxidant and free radical scavenging activities that could contribute, at least in part, to the traditionally claimed therapeutic benefits of persimmon leaves.
TL;DR: In this paper, the in vitro antioxidant activity and in vivo anti-fatigue activity of loach peptide (LP) were determined, which showed that LP contained the amino acids, which were expected to contribute to its antioxidant and antifatigue activities.
TL;DR: In this paper, the authors investigated the phenolic compounds content and antioxidant activity of pomace from the vinification of grape varieties widely produced in Brazil (Cabernet Sauvignon, Merlot, Bordeaux and Isabel) with a view to their exploitation as a potential source of natural antioxidants.
TL;DR: Investigation of the contributions of individual amino acid residues or groups of amino acids to antioxidant activities of some food protein hydrolysates found that sulfur-containing, acidic and hydrophobic amino acids had strong positive effects on scavenging and ferric reducing antioxidant power.
Abstract: The contributions of individual amino acid residues or groups of amino acids to antioxidant activities of some food protein hydrolysates were investigated using partial least squares (PLS) regression method PLS models were computed with amino acid composition and 3-z scale descriptors in the X-matrix and antioxidant activities of the samples in the Y-matrix; models were validated by cross-validation and permutation tests Based on coefficients of the resulting models, it was observed that sulfur-containing (SCAA), acidic and hydrophobic amino acids had strong positive effects on scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and H2O2 radicals in addition to ferric reducing antioxidant power For superoxide radicals, only lysine and leucine showed strong positive contributions while SCAA had strong negative contributions to scavenging by the protein hydrolysates In contrast, positively-charged amino acids strongly contributed negatively to ferric reducing antioxidant power and scavenging of DPPH and H2O2 radicals Therefore, food protein hydrolysates containing appropriate amounts of amino acids with strong contribution properties could be potential candidates for use as potent antioxidant agents We conclude that information presented in this work could support the development of low cost methods that will efficiently generate potent antioxidant peptide mixtures from food proteins without the need for costly peptide purification
TL;DR: The data suggested that antioxidant activity of vanillin might be more beneficial than has been thought for daily health care and the addition of antioxidant capacity to the multifunctionality ofVanillin is proposed.
TL;DR: The results revealed the effect of different extracting solvents in altering the quantitative analyses of all vegetables and 70% acetone was identified as the most efficient solvent for extracting polyphenolic antioxidants from the vegetables.
TL;DR: In this article, the authors investigated the phenolic compounds and antioxidant capacities of free and bound phenolics from 12 available Thai edible flowers which have long been consumed as vegetable and used as ingredients in cooking.
TL;DR: Findings suggest that phenolic content could be used as an indicator of antioxidant properties, and encourage investigations on Mediterranean plant species as sources of antioxidants.
Abstract: Context: Scientific information on antioxidant properties and phenolic content of less widely used plants can be useful. Therefore, the assessment of such properties remains an interesting and useful task, particularly for finding new sources for natural antioxidants, functional foods, and nutraceuticals.Objective: As knowledge about antioxidant properties and phenolic content of many plant species used as traditional plant remedies is limited, we determined in vitro the total antioxidant activity and the phenolic content of several plant species traditionally used for ethnoveterinary practices.Materials and methods: For 24 extracts (70% acetone) from wild and cultivated plant species traditionally used for health care of animals we determined the Trolox equivalent antioxidant capacity (TEAC) by the two assays 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the 2,2′-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS). The phenolic content was determined by the Folin Ciocalteu method.Results...
TL;DR: It is concluded that among Malaysian honey samples, Tualang honey is the richest in phenolic acids, and flavonoid compounds, which have strong free radical-scavenging activities.
Abstract: The phenolic acid and flavonoid contents of Malaysian Tualang, Gelam, and Borneo tropical honeys were compared to those of Manuka honey. Ferric reducing/antioxidant power assay (FRAP) and the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical-scavenging activities were also quantified. All honey extracts exhibited high phenolic contents (15.21 ± 0.51- 42.23 ± 0.64 mg/kg), flavonoid contents (11.52 ± 0.27- 25.31 ± 0.37 mg/kg), FRAP values (892.15 ± 4.97- 363.38 ± 10.57 μM Fe[II]/kg), and high IC₅₀ of DPPH radical-scavenging activities (5.24 ± 0.40- 17.51 ± 0.51 mg/mL). Total of 6 phenolic acids (gallic, syringic, benzoic, trans-cinnamic, p-coumaric, and caffeic acids) and 5 flavonoids (catechin, kaempferol, naringenin, luteolin, and apigenin) were identified. Among the Malaysian honey samples, Tualang honey had the highest contents of phenolics, and flavonoids, and DPPH radical-scavenging activities. We conclude that among Malaysian honey samples, Tualang honey is the richest in phenolic acids, and flavonoid compounds, which have strong free radical-scavenging activities.
Journal Article•
TL;DR: The results showed that there was significant difference (P < 0.05) in total phenolic content and antioxidant activity for kesum, ginger and turmeric extracts as mentioned in this paper.
Abstract: Herb and spices namely kesum, ginger and turmeric were extracted by using juice extractor without the additional of solvent. These herb and spices were determined for moisture content and the extracts were analyzed for total phenolic content (TPC) and antioxidant activity (DPPH radical scavenging assay and FRAP ferric-reducing antioxidant power assay). The yield of kesum, ginger and turmeric extraction was 23.6%, 58.6% and 66.4%, respectively. The results showed that, there was significant difference (P < 0.05) in total phenolic content and antioxidant activity for kesum, ginger and turmeric extracts. Kesum extract had the highest total phenolic content followed by ginger and turmeric extract. A significant and positive high Pearson's correlations between TPC and DPPH assay (r = 0.86) and between TPC and FRAP assay (r = 0.91) respectively was observed for all plants extracts. This indicated that phenolic compounds were the main contributor of antioxidant activity in plants. However, there was no synergistic effect observed for all plants extract mixture.
TL;DR: Results indicate that rice brans are natural sources of hydrophilic and lipophilic phytochemicals for use in quality control of various food systems as well as for nutraceutical and functional food application.
Abstract: Rice bran, a byproduct of the rice milling process, contains most of the phytochemicals. This study aimed at determining the concentrations of lipophilic, solvent-extractable (free), and cell wall-bound (bound) phytochemicals and their antioxidant capacities from brans of white, light brown, brown, purple, and red colors, and broccoli and blueberry for comparison. The concentrations of lipophilic antioxidants of vitamin E (tocopherol and tocotrienols) and γ-oryzanols were 319.67 to 443.73 and 3861.93 to 5911.12 μg/g bran dry weight (DW), respectively, and were not associated with bran color. The total phenolic, total flavonoid, and antioxidant capacities of ORAC (oxygen radical absorbance capacity), DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging, and iron-chelating in the free fraction were correlated with the intensity of bran color, while variations of these in the bound fraction were less than those in the free fraction among brans. Compounds in the bound fraction had higher antioxidant capacity of ORAC than DPPH, relative to those in the free fraction. The bound fraction of light-color brans contributed as much to its total ORAC as the free fraction. Total proanthocyanidin concentration was the highest in red rice bran, while total anthocyanin was highest in purple brans. The predominant anthocyanin was cyanidin-3-glucoside. Red and purple brans had several fold higher total phenolics and flavonoids as well as ORAC and DPPH, from both free and bound fractions, than freeze-dried blueberry and broccoli. These results indicate that rice brans are natural sources of hydrophilic and lipophilic phytochemicals for use in quality control of various food systems as well as for nutraceutical and functional food application.