Evaluation of phenolic contents and antioxidant activities of brown seaweeds belonging to Turbinaria spp.(Phaeophyta,Sargassaceae) collected from Gulf of Mannar

Objective:To evaluate the antioxidant activities and total phenolic contents of brown seaweeds belonging to Turbinaria spp.[Turbinaria conoides(T.conoides)and Turbinaria ornata(T.ornata)collected from Gulf of Mannar of southeastern coast of India in various in vitro systems.Methods:The antioxidant activity was evaluated using different in vitro systems,viz.,I,I-diphenyl-2-picrylhydrazyl(DPPH),2,2'-azino-bis-3 ethylbenzothiozoline-6-sulfonic acid diammonium salt(ABTS),H_20_2/H0 radical scavenging,Fe^(2+)ion chelating ability,and reducing potential.Folin-Ciocalteu method was used to determine the total phenolic content of the extracts,and the results were expressed as mg of gallic acid equivalents(GE)/g of the seaweed extracts.Thiobarbituric acid-reactive substances assay was employed to assess the ability of the seaweed extracts to inhibit lipid oxidation.Results:Ethyl acetate(EtOAc)fraction of T.conoides registered significantly higher phenolic content(105.97 mg GE/g)than that of T.ornata(69.63 mg GE/g).Significantly higher antioxidant potential as determined by DPPH(64.14%)radical scavenging activity was registered in EtOAc fraction of T.ornata.A higher ABTS(?)radical scavenging(IC_(50)3.16μg/mL),Fe^(2+)chelating(IC_(50)0.46 mg/mL),H_2O_2 scavenging(IC_(50)4.25 mg/mL),lipid peroxidation inhibitory(TBARS,IC_(50)0.21 mg/mL),and reducing abilities(IC_(50)52.67 mg/mL)(P<0.05)were realized in EtOAc fraction of T.ornata than other fractions.Conclusions:This study indicated the potential use of T.conoides and T.ornata as candidate species to be used as food supplements/functional foods to increase shelf-life of food items for human consumption,and nutraceuticals to deter deleterious free radical-induced life-threatening diseases.

Influence of Jet-Cooking Corn Bran on Its Antioxidant Activities, Phenolic Contents and Viscoelastic Properties

Corn bran was subjected to high-shear and jet-cooking with or without alkaline treatment. The highest antioxidant activity was found in the soluble solids from jet-cooked corn bran without alkaline treatment. Jet-cooking under alkaline conditions resulted in a soluble fraction having the highest phenolic content but without increasing antioxidant activity. Phenolic contents of soluble solids were significantly higher than the insoluble solids. A colorimetric method using spectrophotometer was suitable to determine total phenolic content, whereas LC-ESI-MS technology was used for identifying important individual phenolic acids, namely caffeic, coumaric and ferulic acid. The insoluble solids from alkaline treatment had the highest water holding capacity and interesting viscoelastic properties. These results suggested that jet-cooking corn bran may be a useful processing procedure for creating phytochemical and functional products.

Evaluation of extracts and essential oil from Callistemon viminalis leaves:Antibacterial and antioxidant activities,total phenolic and flavonoid contents

Objective:To investigate antioxidant and antibacterial activities of Callistemon viminalis(C.viminalis)leaves.Methods:The essential oil of C.viminalis leaves obtained by hydrodistillation was analyzed by GC/MS.Different extracts were tested for total phenolic and flavonoid contents and in vitro antioxidant(DPPH assay)and antibacterial(agar disc diffusion and 96-well micro-plates methods)actives.Results:Fourteen components were identified in the essential oil,representing 98.94%of the total oil.The major components were 1,8-cineole(64.53%)andα-pinene(9.69%).Leaf essential oil exhibited the highest antioxidant activity of(88.60±1.51)%comparable to gallic acid,a standard compound[(80.00±2.12)%].Additionally,the biggest zone of inhibitions against the studied bacterial strains was observed by the essential oil when compared to the standard antibiotic(tetracycline).The crude methanol extract and ethyl acetate fraction had a significant antibacterial activity against the tested bacterial strains.Conclusions:It can be suggested that C.viminalis is a great potential source of antibacterial and antioxidant compounds useful for new antimicrobial drugs from the natural basis.The present study revealed that the essential oil as well as the methanol extracts and ethyl acetate fraction of C.viminalis leaves exhibited highly significant antibacterial activity against the tested bacterial strains.

Measurement of total phenolic content and antioxidant activity of aerial parts of medicinal plant Coronopus didymus

Objective: To evaluate the total phenolic content and compare the antioxidant activity of various solvent extracts and fractions from the aerial parts of Coronopus didymus through various assays. Methods: Total phenolic content was determined using the Folin-Ciocalteu assay and the in vitro antioxidant activity of a number of different extracts was investigated in a dose-dependent manner with three different methods: the 2,2-diphenyl-1-picrylhydrazyl(DPPH), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt(ABTS) and ferric reducing antioxidant power(FRAP) assays. A flavone was isolated from the most active ethanolic extract with high antioxidant activity using size exclusion chromatography. IC_(50) values were calculated for the DPPH and ABTS methods. The FRAP activity was assessed in terms of μM Fe(II) equivalent. Results: The phenolic content was found to be highest in the ethanol extract(CDA Et; 47.8 mM GAE) and the lowest in the dichloromethane extract(CDA DCM; 3.13 mM GAE). The ethanol extract showed high radical scavenging activity towards DPPH and ABTS radicals with IC_(50) values of(7.80 × 10~2) and(4.32 × 10~2) μg/m L, respectively. The most active ethanol extract had a FRAP value of 1 921.7 μM Fe(Ⅱ) equivalent. The isolated flavone F10C(5,7,4'-trihydroxy-3'-methoxy flavone) was far more effective for scavenging free radicals in the DPPH and ABTS assays with IC_(50) of 43.8 and 0.08 μg/m L, than the standard trolox, with IC_(50) values of 97.5 and 21.1 μg/m L, respectively. In addition, the flavone F10C and the standard ascorbic acid had FRAP values of 1 621.7 and 16 038.0 μM Fe(Ⅱ) equivalents, respectively. Conclusions: The total phenolic content of extracts in decreasing order is ethanol extract(CDA Et)> acetone extract(CDA ACE)> phenolic extract(CDA MW)> n-hexane extract(CDA nHX)> chloroform extract(CDA CHL)> dichloromethane extract(CDA DCM). The ordering of extracts in terms of antioxidant activity from highest to lowest is CDA Et> CDA MW> CDA DCM> CDA CHL> CDA ACE> CDA nHX in DPPH, ABTS and FRAP assays. A significant relationship is found between antioxidant potential and total phenolic content, suggesting that phenolic compounds are the major contributors to the antioxidant activity of Coronopus didymus.

Antioxidant activity and total phenolic content of essential oils and extracts of sweet basil(Ocimum basilicum L.)plants

The present study was conducted to evaluate the chemical composition and antioxidant activity of the essential oils and ethanol extracts of Ocimum basilicum L.obtained from Assiut,Minia and BeniSuef of Egypt.The major constituents of sweet basil essential oils from three locations were linalool,estragole,methyl cinnamate,bicyclosesquiphellandrene,eucalyptol,-bergamotene,eugenol,-cadinene and germacrene D by the method of GC–MS.The relative concentration of these compounds varies.The basil extracts contained appreciable levels of total phenolic contents and exhibited good DPPH radical scavenging capacity higher than that of essential oils.The highest TPC(82.45 mg PE/g)and maximum radical scavenging activity with IC50 value(1.29 mg/mL)was obtained from Minia basil extract.High correlation between antioxidant activity and total phenolic contents of basil extracts was observed.High variation in free radical scavenging activity of essential oils was found.The essential oil from Minia basil showed high activity in DPPH radical scavenging with IC50(11.23 mg/mL)and contained the highest content of phenolic(41.3 mg PE/g).On contrary,low correlation between antioxidant activity and total phenolic contents of basil essential oils from different locations.The results of the present investigation demonstrated significant variations in the antioxidant activities of sweet basil essential oils and extracts from Egypt.

Comparison of Total Phenolic Content and Total Antioxidant Activity in Local Red Wines Determined by Spectrophotometric Methods

In this study, the antioxidant activity of local red wines was determined by four different analytical methods: 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS?+) radical cation decolourisation, ferric reducing/antioxidants power (FRAP) and cupric ion reducing capacity in the presence of neocuproine (CUPRAC) for the evaluation of reducing power (PR). They were correlated with the total phenolic content (TPC) determined with the Folin-Ciocalteu’s reagent using gallic acid as a standard. The total polyphenol concentration was found to vary from 2599.90 to 4846.57 mg/L gallic acid equivalents (GAE). The total antioxidant activity determined by DPPH, ABTS, FRAP and CUPRAC methods was found to vary from 7.49 - 15.93 mmol/L, 12.02 - 24.73 mmol/L, 12.65 - 27.68 mmol/L and 13.19 - 31.07 mmol/L, respectively. The total phenolic contents of red wine samples exhibited a good correlation (p < 0.01) with antioxidant properties.

Estimation of total phenolic content,in-vitro antioxidant and anti-inflammatory activity of flowers of Moringa oleifera

Objective:To evaluate and compare the antioxidant potential and anti-inflammatory activity of ethanolic extract of flowers of Moringa oleifera(M.oleifera)grown in Oman.Methods:Flowers of M.oleiferawere collected in the month of December 2012 and identified by a botanist.Alcoholic extract of the dry pulverized flowers ofM.oleiferawere obtained by cold maceration method.The ethanolic flower extract was subjected to preliminary phytochemical screening as the reported methods.Folin-Ciocalteu reagent was used to estimate total phenolic content.DPPH was used to determinein-vitroantioxidant activity and anti-inflammatory activity of flowers was investigated by protein denaturation method.Results:Phytochemical analysis of extract showed presence of major classes of phytochemicals such as tannins,alkaloids,flavonoids,cardiac glycosidesetc.M.oleiferaflowers were found to contain 19.31 mg/g of gallic acid equivalent of total phenolics in dry extract but exhibited moderate antioxidant activity.The anti-inflammatory activity of plant extract was significant and comparable with the standard drug diclofenac sodium.Conclusions:The results of our study suggest that flowers ofM.oleiferapossess potent anti-inflammatory activity and are also a good source of natural antioxidants.Further study is needed to identify the chemical compounds responsible for their anti-inflammatory activity.

Effect of Superfine Grinding on Physicochemical Properties, Antioxidant Activity and Phenolic Content of Red Rice ( <i>Oryza sativa</i>L.)

Red rice gains popularity as a functional crop owing to its high polyphenols content and antioxidant activity. However, active components are discarded in common milling. Superfine ground technology was employed in this paper. To evaluate the influence of superfine ground processing on the physicochemical properties and functional effect of red rice (Oryza sativa L.), four powders with the size of 156.74 μm, 69.53 μm, 26.35 μm, and 10.68 μm were prepared by superfine grinding technology in this paper. Results showed that the size was smaller for red rice powders, greater for the bulk density (from 0.624 g/ml to 0.745 g/ml), and smaller for the angle of repose (from 74.67&deg;to 61.41&deg;) and slide (from 38.99&deg;to 26.42&deg;). The values of water solubility index, water holding capacity and enzymatic digestibility by α-amylase significantly increased with the decreasing particle size (P < 0.05). In addition, antioxidant activity and phenolic content were enhanced by superfine ground. These results indicated that superfine ground would improve the physicochemical and functional properties of red rice, which was helpful to promote the overall quality and healthy effect of foods containing red rice.

Effect of Gamma Irradiation on Total Phenolic Content and <i>in Vitro</i>Antioxidant Activity of Pomegranate (<i>Punica granatum</i>L.) Peels

Pomegranate peels were studied for the effect of gamma irradiation on microbial decontamination along with its effect on total phenolic content and in vitro antioxidant activity. Gamma irradiation was applied at various dose levels (5.0, 10.0, 15.0 and 25.0 kGy) on pomegranate peel powder. Both the values of total phenolic content and in vitro antioxi- dant activity were positively correlated and showed a significant increase (p < 0.05) for 10.0 kGy irradiated dose level immediately after irradiation and 60 days of post irradiation storage. At 5.0 kGy and above dose level, gamma irradia- tion has reduced microbial count of pomegranate peel powder to nil. Post irradiation storage studies also showed that, the irradiated peel powder was microbiologically safe even after 90 days of storage period.

Antioxidant and Phenolic Content of Nuts, Oil Seeds, Milk and Milk Products Commonly Consumed in India

Food provides not only essential nutrients required for life, but also bioactive compounds usefull to maintan good health and disease prevention. Abundant epidemiological evidences suggest that consumption of food rich in antioxi-dants (non-nutritional components) can prevent degenerative diseases. A total of 26 commonly consumed nuts, oil seeds, edible oils, milk and milk products were chosen for the study. Considering the fact that antioxidant content (AOC) and phenolic contents (PC) of these foods was not established systematically in Indian context. Therefore, we have assessed and correlated the AOC and PC, an important antioxidant constituents of plant foods. AOC was assessed by DPPH (2, 2-Diphenyl-1-picryl hydrazyl) scavenging activity and FRAP (Ferric reducing antioxidant power) methods and phenolic content (PC), using Folin-Ciocalteu reagent. Among the nuts and oil seeds arecanut had the highest phenolic and antioxidant content 10841, 4220341 mg/100g respectively. In milk, edible oils and sugars the values ranged from 336 -11674 mg/100g. Jaggery had the highest PC and AOC among the foods studied . Although AOC and PC showed wide variation among the foods, AOC was correlated significantly with PC. Indeed the ‘r’ value between PC and AOC (DPPH and FRAP) was 0.99 (p < 0.01) among the nuts and oil seeds, while in milk, milk products and sugars, the “r” values ranged from 0.93 and 0.99 (p < 0.01) respectively. The overall results indicate that the phenolic compounds may be significant contributors to the AOC of the foods studied.

Total Phenolic Content and Antioxidant Activity of Standardized Extracts from Leaves and Cell Cultures of Three Callistemon Species

A comparative study was carried out with ethanolic (80%) extracts from leaves and cell cultures of three Callistemon species, namely C. lanceolatus (CL), C. viridiflorous (CV), and C. comboynensis (CC). Cell suspensions of the three species were grown in liquid Murashige and Skoog (MS) medium (100 ml) supplemented with 0.9 mg·g-1 kinetin in combination with 1.1 mg·g-1 NAA. The CL leaf extract was standardized to contain the highest amount of phenolics (104 ± 2.0 mg·g-1), followed by CC (95.8 ± 1.2 mg·g-1) and CV (79.8 ± 4.6 mg·g-1). On the other hand, cell cultures of CV contained more phenolics (14.9 ± 0.6 mg·g-1) than those of the other two species, CL and CC, which contained 12.2 ± 0.16 and 9.12 ± 0.16 mg·g-1, respectively. Nevertheless, CV leaf extract exhibited the highest antioxidant activity (91.4% ± 0.4%) at a concentration of 1000 μg·ml-1, comparable to 100 μg·ml-1 gallic acid (90.8% ± 1.5%).

Comparison among Cornelian Cherry and <i>Prunus cerasus</i>According to Phenolic Content and Antioxidant Capacity by Three Various Methods of Extraction

Cornelian cherry and Prunus cerasus with red pigments possess precious source of flavonoids and phenolic acids which have various applications in treatment of various health problems. This study is conducted to compare different methods of extraction (shaking incubator, soxhelet, ultrasonic) were applied in order to identify the best method which shows the highest rate of antioxidant capacity by DPPH and ferric reducing antioxidant power (FRAP) methods and total phenolic compounds via Folin-Ciocalteu procedure, p-coumaric acid content of fruits were evaluated by high performance liquid chromatography (HPLC). As a result, cornelian cherry with 1313.13 mg/Kg average TPC score exhibits higher total phenolic content than Prunus cerasus with 1270 mg/Kg. It’s notice worthy that there was a slight difference among antioxidant activity in two fruits. Consequently, DPPH revealed nearly stronger antioxidant activity for Prunus cerasus while cornelian cherry had a little more potent antioxidant activity according to FRAP Test. p-coumaric acid content was almost twice in Prunus cerasus (10.8 mg/ml) than cornelian cherry (5.6 mg/ml). In addition, both shaking incubator and ultrasonic extraction procedures were more efficient than soxhelet in two fruits.

Comparative analysis of antioxidant activities of essential oils and extracts of fennel(Foeniculum vulgare Mill.)seeds from Egypt and China

The present study was conducted to assay the antioxidant activities of essential oils and ethanol extracts of fennel(Foeniculum vulgare Mill.)seeds from Egypt and China.The major components of the Egyptian fennel essential oil were estragole(51.04%),limonene(11.45%),l-fenchone(8.19%)and trans-anethole(3.62%)by GC–MS analysis.Whereas,the major constituents of Chinese fennel essential oil were transanethole(54.26%),estragole(20.25%),l-fenchone(7.36%)and limonene(2.41%).The fennel seed extracts from Egypt and China contained appreciable levels of total phenolic contents(42.24 and 30.94 mg PE/g,respectively).The extracts exhibited good DPPH radical scavenging capacity with IC50(6.34 and 7.17 mg/g),respectively.A high variation in free radical scavenging activities of essential oils was observed.The Chinese fennel essential oil showed high activity in DPPH radical scavenging with IC50(15.66 mg/g).The Egyptian fennel essential oil showed very low activity with IC50(141.82 mg/g).The results of the present investigation demonstrated significant variations in the antioxidant activities of fennel essential oils and extracts from Egypt and China.

In vitro antioxidant activities of ethanol extract from Enhalus acoroides (L.F.) Royle

Objective:To search for new sources of safe and inexpensive antioxidants,the leaf,root and rhizome of Enhalus acoroides(E.acoroides) were screened for the first time for their antioxidant activities.Methods:Samples of leaf,root and rhizome from E.acoroides were tested for total phenolic content,proanthocyanidins and in vitro antioxidant activity in terms of total antioxidant assay,DPPH assay and FRAP assay.Results:The leaf sample was found to have high levels of phenolic(0.323±0.028 mg TAE/g) and proanthocyanidins(0.570 0±0.000 3 mg TAE/g) when compared to root and rhizome.The leaf samples exhibited higher total antioxidant activity (11.770±0.026 mg Ascorbic acid equivalent/g),higher percentage of DPPH radical scavenging activity(25.76±0.04) and higher reducing power(18.060±0.073) in terms of mg GAE/g.In addition, there was a significant correlation between total phenolic content and total antioxidant activity (R^2=0.923),DPPH assay(R^2=0.509).FRAP assay(R^2=0.994).Similarly,significant correlation was found between the proanthocyanidin and total antioxidant activity(R^2=0.977),DPPH assay (R^2=0.464) and the FRAP assay(R^2=0.998).Conclusions:These results suggested that E.acoroides have strong antioxidant potential.Further study is necessary for isolation and characterization of the active antioxidant agents,which can be used to treat various oxidative stress-related diseases.

In vitro antioxidant activities of selected seaweeds from Southeast coast of India

Objective:In vitro antioxidant activities of three selected Indian seaweeds viz.,Halimeda tuna(H.tuna),Turbinaria conoides(T.conoides) and Gracilaria foliifera(G.foliifera) were evaluated.Methods:Total antioxidant activity,total phenolic content,and reducing power of crude methanol and diethyl ether extracts were determined.Results:Total phenolic content and total antioxidant activity were higher(1.231±0.173 mg GAE/g,1.675±0.361 mg GAE/g) in T.conoides respectively.Reducing power of crude methanol extract increased with concentrations of the extract.The Fourier transform-infra red spectrum analysis revealed the presence of polyphenolic signals.The seaweed extracts displayed moderate antioxidant activity compared to gallic acid standard.Conclusions:The seaweeds could be considered for curing diseases from oxidative deteriorations.

Total phenolic, flavonoid content, and antioxidant activity of flour, noodles, and steamed bread made from different colored wheat grains by three milling methods

The objective of this study was to evaluate the effects of wheat variety, food processing, and milling method on antioxidant properties. Black wheat variety Heibaoshi 1 had the highest total phenolic content(659.8 μg gallic acid equivalents g-1), total flavonoid content(319.3 μg rutin equivalents g-1), and antioxidant activity, whereas light purple wheat variety Shandongzimai 1 had the lowest total flavonoid content(236.2 μg rutin equivalents g-1) and antioxidant activity. Whole wheat flour and partially debranned grain flour had significantly higher total phenolic contents, total flavonoid contents, and antioxidant activity than refined flour(P < 0.05). Compared with flour, total phenolic contents, total flavonoid contents and antioxidant activity decreased in noodles and steamed bread, whereas noodles had slightly higher total phenolic and flavonoid content than steamed bread. Antioxidant activities(by ferric reducing ability of plasma assay) of steamed bread made from whole wheat flour, partially debranned grain flour, and refined flour were 23.5%, 21.1%, and 31.6% lower, respectively, than the corresponding values of flour. These results suggested that black whole wheat flour and partially debranned grain flour are beneficial to human health.

GC-MS analysis,determination of total phenolics,flavonoid content and free radical scavenging activities of various crude extracts of Moringa peregrina(Forssk.) Fiori leaves

Objective:To perform phytochemical screening,estimate total phenolics,flavonoids and to evaluate antioxidant potential of Moringa peregrina(M.peregrina) leaves.Methods:The dried powdered leaves of M.peregrina(150 g) were extracted exhaustively by Soxhlet with ethanol and then fractionated into hexane,chloroform,ethy alacetate and methanol.All the prepared extracts were also analyzed by gas chromatography-mass spectrometry to identify and characterize the chemical compounds present in the crude extracts.Folin- Ciocalteu reagent and aluminium chloride colorimetric methods were used to estimate total phenolic and flavonoid content of extracts.Hydrogen peroxide and 1,1 diphenyl-2-picrylhydrazyl were used to determine in vitro antioxidant activity.Results:Phytochemical analysis of ethanol extract showed presence of major classes of phytochemicals.Gas chromatography-mass spectrometry results revealed presence of 19 phytoconstituents in hexane extract,6 in ethyl acetate and 7 compounds in methanolic extract.Methanol extract was found to contain the highest phenolic content and flavonoids.In vitro antioxidant activities of all crude extracts were significant and comparable with the standard ascorbic acid.Conclusions:Results of this study show that the leaves of M.peregrina are the rich source of phenolic compounds that can play an important role in preventing the progression of many diseases.

An Evaluation on Antioxidant Activity, Total Phenolic and Total Flavaonoid Contents of Extracts from <i>Adina cordifolia</i>(Roxb.)

In this study, in vitro antioxidant activity, total phenolic content and concentration of flavonoids of four different extracts of Adina cordifolia (Roxb.) were determined using spectrophotometric methods. Antioxidant activity of extracts was expressed as percentage of DPPH radicals’ inhibition and IC50 values (μg/ml). IC50 values ranged from 20.39 to 38.96 μg/ml. The total phenolic content ranged from 17.48 to 20.83 mg/g of dry weight of extract, expressed as gallic acid equivalents. The total flavonoid concentrations varied from 17.49 to 22.48 mg/g, expressed as quercetin equivalents. The significant linear correlation was confirmed between the values for the total phenolic content and antioxidant activity of plant extracts. Adina cordifolia (Roxb.) can be regarded as promising candidates for natural plant sources of antioxidants with high value.

Antioxidant Activities of Nine Selected Culinary Spices from China

The antioxidant activities and the total phenolic contents of the water and/or ethanol extracts of the nine selected culinary spices from China were systematically investigated. Both ethanol extracts and water extracts had high ability of 1, 1-diphenyl-2-picrylhydrazyl（DPPH） radical scavenging, 2, 2＇-azinobis（3-ethylbenzthiazoline-6-sulphonic acid）（ABTS） radical scavenging and ferric reducing antioxidant power（FRAP）. The ethanol extract of Sichuan pepper showed the highest ability of DPPH radical scavenging. The extract with the highest ABTS radical scavenging effect was that of ethanol extract of cinnamon. Both ethanol and water extracts of cinnamon possessed the high ferric reducing antioxidant power（FRAP） with the values of 4 541.87 and 1 134.52 μmol of Fe（Ⅱ）/g. The extracts with high hydroxyl radical-mediated deoxyribose degradation were all the ethanol extracts as follows： cinnamon, bay leaf, Sichuan pepper, star anise and fennel. The extracts with high antioxidant activities also had the high contents of the phenols. The study indicated that these spices might be potentially be used as natural antioxidants in food.

Diversity of Antioxidant Content and Its Relationship to Grain Color and Morphological Characteristics in Winter Wheat Grains

The current interest in the health beneifts of whole wheat grain has prompted breeders to further increase the concentration of antioxidants in wheat. The objective of this study was to investigate the variation in antioxidant content among Chinese wheat grains and the relationship between antioxidants and grain color and morphological characteristics. A wide variation was observed in the total phenolic, carotenoid and lfavonoid contents, as well as the antioxidant activity （AOA）, of Chinese wheat varieties. Black wheat had the highest mean total phenolic, carotenoid and lfavonoid contents and the highest AOA, followed by red and white wheats. The grain color parameters were signiifcantly negatively correlated with total phenolic, carotenoid and lfavonoid contents and AOA among all of the wheat varieties examined, and grain weight was also signiifcantly negatively correlated with these traits. The same correlation between grain weight and antioxidant traits was also observed within individual groups of wheat, which indicates that grain weight may be used as an index for selecting wheat varieties with high AOA. Landraces had signiifcantly higher lfavonoid content than commercial wheat varieties. The results of this study may be useful for breeding nutrient-rich wheat varieties.