scholarly journals Content of selenoaminoacids and catechins in Chinese green teas

2020 ◽  
Author(s):  
Aleksandra Sentkowska
Keyword(s):  
Mass Spectrometry ◽  
Antioxidant Activity ◽  
Radical Scavenging ◽  
Speciation Analysis ◽  
Selenium Content ◽  
Hydrophilic Interaction ◽  
Organic Selenium ◽  
Reducing Ability ◽  
Inorganic Selenium ◽  
Tea Infusions

AbstractIn this study, famous Zhejiang teas were evaluated as a well-advertised source of selenium. The 25 samples from provinces around China and Asia were purchased in Warsaw tea shops. The speciation analysis of selenium as well as the evaluation of catechin content in water tea infusions was performed using hydrophilic interaction liquid chromatography coupled to mass spectrometry (HILIC-MS/MS). It turned out that all of tested samples can be a great source of organic selenium species (no traces of inorganic selenium was found), however, Zhejiang teas did not differ much among others. Such a conclusion can also be drawn when comparing the antioxidant capacity of the tested samples, obtained with the application of four methods (Folin–Ciocalteu method, scavenging of the 2,2-diphenyl-1-picrylhydrazyl radical, hydroxyl radical scavenging and cupric reducing ability assay). What is more, no correlation was found between the selenium content and the antioxidant activity of studied teas. The results obtained for the six samples from Zhejiang Province were very varied, which shows that it is very difficult to interpret the results and compare them with the results of other authors.

Evaluation of antioxidant and Anthelmintic activity of methanolic flower extract of Nyctanthes arbor-tristis

2018 ◽  
Vol 9 (1) ◽  
pp. 78
Author(s):  
Vijaya Jyothi M ◽  
Bhargav E ◽  
Pavan Kumar K ◽  
Praneeth Gowd K ◽  
Ram Pavan S
Keyword(s):  
Antioxidant Activity ◽  
Radical Scavenging Activity ◽  
Iridoid Glycosides ◽  
Radical Scavenging ◽  
Anthelmintic Activity ◽  
Total Phenolic ◽  
Standard Drug ◽  
Flower Extract ◽  
Reducing Ability ◽  
Total Flavonoids Content

Nyctanthes arbour-tristis is a shrub belongs to the family Oleaceae. The flowers of this plant are fragrant since the presence of flavonol glycosides. It has also been reported for the presence of β-sitosterol, iridoid glycosides, tannins etc., and known to have immunostimulant, hepatoprotective, antiviral and antifungal activities. In the present study an attempt is made to identify antioxidant capacity and anthelminthic potential of methanolic flower extract of Nyctanthes arbour-tristis. Antioxidant activity was evaluated by total phenolic content assay, total flavonoids content assay, free radical scavenging activity and reducing ability methods. Anthelmintic activity was evaluated on Perithima posthuma using Piperazine citrate as standard drug. The results obtained for the above activities reveals that Nyctanthes arbour-tristis shows considerable antioxidant activity for all the methods and anthelminthic potential at 300 mg/ml. Keywords: arbour-tristis; antioxidant activity; anthelminthic activity; Perithima posthuma; Piperazine citrate.

scholarly journals Evaluation of Reducing Ability and Antioxidant Activity of Fruit Pomace Extracts by Spectrophotometric and Electrochemical Methods

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Georgii S. Vasyliev ◽  
Victoria I. Vorobyova ◽  
Olga V. Linyucheva
Keyword(s):  
Antioxidant Activity ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Potassium Ferricyanide ◽  
Grape Pomace ◽  
Black Currant ◽  
Ferricyanide Reduction ◽  
Electrochemical Testing ◽  
Reducing Ability ◽  
Fruit Pomace

The component profiles of apricot, grape, and black currant pomace extracts have been analyzed using HPLC coupled to diode-array detection and tandem mass spectrometry (HPLC-DAD-MS). The predominant components in grape, apricot, and black currant pomace extracts were phenolic acids and flavonols. The redox behavior of apricot, black currant, and grape pomace water extracts was evaluated by means of cyclic voltammetry. Also, individual substances mainly present in the extracts were analyzed. The results of electrochemical testing were compared to traditional chemical techniques of potassium ferricyanide reduction (FRAP) and phosphomolybdenum assay, and fair agreement was established. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging assays were applied in order to estimate antioxidant activity. The reducing power of the grape extract was found to be higher than that of the apricot and black currant extracts in both potassium ferricyanide reduction (FRAP) and phosphomolybdenum methods.

scholarly journals Bioactive Compounds of Selected Fruit Juices

2009 ◽  
Vol 4 (5) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Aneta Wojdyłto ◽  
Jan Oszmiański
Keyword(s):  
Antioxidant Activity ◽  
Phenolic Compounds ◽  
Fruit Juice ◽  
Biological Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Sea Buckthorn ◽  
Quercetin Derivatives ◽  
Reducing Ability ◽  
Wide Range

Fruits are one of the most important sources of phenolic compounds in our diet. Many of these compounds exhibit a wide range of biological activities, especially antioxidant activity. The objective of this study was to determine the composition and antioxidant activity of phenolic compounds found in fruit juice obtained from buckthorn, flowering quince, rowanberry and hawthorn. Hydroxycinnamic acids (neochlorogenic and chlorogenic acid) and procyanidins were the main phenolics in rowanberry juice. The highest level of flavonols (quercetin derivatives) was found in sea buckthorn. All juices showed strong free-radical scavenging activity against ABTS•+ radicals and ferric reducing ability measured by the FRAP method. The strongest antioxidant activity was found in rowanberry juice, but the lowest was measured in hawthorn and sea buckthorn juices.

In vitro Evaluation of Antioxidant Activity of the Methanol and Ethanol Extracts of Pistacia atlantica Desf from Morocco

2019 ◽  
Vol 17 (6) ◽  
pp. 321-333
Author(s):  
Z. Khiya ◽  
Y. Oualcadi ◽  
A. Gamar ◽  
S. Amalich ◽  
F. Berrekhis ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Cyclic Voltammetry ◽  
Ethyl Acetate ◽  
Antioxidant Capacity ◽  
Radical Scavenging Activity ◽  
Condensed Tannin ◽  
Radical Scavenging ◽  
Maximal Response ◽  
Pistacia Atlantica ◽  
Reducing Ability

The aim of this work is to evaluate the antioxidant effects of the extracts of Pistacia atlantica collected in the Khenifra region (Morocco) in 2016. Different methods were used to study these extract: 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, the ferric reducing ability of plasma (FRAP) assay, the phosphomolybdate method for determining the total antioxidant capacity, and the electrochemical method for cyclic voltammetry were employed to evaluate the antioxidant capacity of Pistacia atlantica Desf. Phytochemical screening helped us to highlight the presence of secondary metabolites. The extraction of the phenolic compounds was carried out by the Soxhlet method in the presence of different mixtures solvents (ethanol/water and methanol/water); the fractions of the different extracts were affected using ethyl acetate and n-butanol. The dosage results showed that the ethanolic extract was rich in total phenols (260.4 mg GAE/g of the extract) and in total flavonoids (129.15 mg QE/g of the extract), while the butanolic fraction was rich in condensed tannin (50.96 mg CE/g of the extract). The qualitative analysis was performed by high performance liquid chromatography (HPLC). The main compounds that were identified in the methanolic and ethanolic extracts of Pistacia atlantica Desf were ascorbic acid, gallic acid, tannic acid, rutin, and quercetin. The results of the antioxidant activity revealed that the butanolic and ethyl acetate fractions exhibit a good iron reduction capacity (concentration that gave half maximal response, EC50 = 0.02 mg/ml and 0.03 mg/ml, respectively) and a very interesting antiradical activity with an IC50 (concentration of inhibitor where the response is reduced by half) = 0.08 mg/ml and 0.04 mg/ml, respectively. Cyclic voltammetry presented a single oxidation peak between 400 and 500 mV. The ethanolic and methanolic extracts were recorded from the oxidation currents values of 15.75 and 10.41 i/μA cm.2 respectively at the concentration 0.1 mg/ml. Hence, it is clear that the leaves of Pistacia atlantica Desf, which are currently often considered as potential antioxidants, contain antioxidants that can usefully be extracted and added to foods.

scholarly journals Effects of Cold and Hot Infusions on Antioxidant Activities of Rosehip Tea Bag

2021 ◽  
Vol 9 (8) ◽  
pp. 1455-1459
Author(s):  
Zeynep Akar ◽  
Erza Orhan ◽  
Seçil Durmuş
Keyword(s):  
Antioxidant Activity ◽  
Lower Energy ◽  
Antioxidant Activities ◽  
Radical Scavenging ◽  
Total Phenolic ◽  
Energy Costs ◽  
Antioxidant Power ◽  
Tea Infusions ◽  
Different Temperatures ◽  
Determination Methods

In this study, the antioxidant activity values of infusions at different temperatures of the commercially sold rosehip tea bag. To determine the effect of different infusion temperatures on antioxidant activity, 7 different temperatures (0, 15, 30, 45, 60, 75, 90°C) also including cold infusions temperatures were selected. Infusions of the rosehip tea bags were prepared with packaged drinking water for 5 minutes (recommended time in tea bag packaging) at these temperatures. Antioxidant activity values of the infused extracts were determined by antioxidant activity determination methods: TPC (Total Phenolic Compound), CUPRAC (Cu (II) Ion Reducing Antioxidant Capacity), FRAP (Iron (III) Ion Reducing Antioxidant Power) and ABTS•+ (2.2-azinobis- (3-ethylbenzothiazoline-6-sulphonic acid)) radical scavenging assay. According to the results obtained by the antioxidant determination methods, the highest and lowest activity values for TPC, FRAP and ABTS were measured at 90°C and 0°C, respectively, and a positive correlation was found between temperature and antioxidant activity values. Contrary to the activity values determined in these methods, in the CUPRAC method, the highest and the lowest activity value was measured at 45°C and 90 °C, respectively. As determined in the CUPRAC method, infusions of rosehip tea at low temperatures may provide an advantage in terms of the solubility of some phenolics that can be denatured at high temperatures. In addition, rosehip tea infusions at lower temperatures will contribute to lower energy costs.

scholarly journals Bagged Aronia Melanocarpa Tea: Phenolic Profileand Antioxidant Activity / Aronia Melanocarpa Filter Čaj: Fenolni Profil I Antioksidativna Aktivnost

2014 ◽  
Vol 31 (4) ◽  
pp. 245-252 ◽  
Author(s):  
Jovana Veljković ◽  
Jelena Brcanović ◽  
Aleksandra Pavlović ◽  
Snežana Mitić ◽  
Biljana Kaličanin ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Caffeic Acid ◽  
Antioxidant Activities ◽  
Biological Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Scavenging Activity ◽  
Antioxidant Power ◽  
Aronia Melanocarpa ◽  
Tea Infusions

Summary While there is a large number of scientific papers reporting chemical composition and biological activities of Aronia melanocarpa, there is a lack information regarding the commercially available bagged tea. In order to supply new information on the antioxidant activity of the Aronia melanocarpa tea infusions, the aim of this study was to evaluate individual phenolic compounds which could be responsible for antioxidant activities of these beverages. Selected anthocyanins (cyanidin-3-O-galactoside, cyanidin-3-O-glucoside, cyanidin- 3-O-arabinoside, and cyanidin-3-O-xyloside), gallic acid, caffeic acid, rutin, morin, and protocatechuic acid were simultaneously detected from commercially available tea infusions using a High Performance Liquid Chromatographic (HPLC) method. The antioxidant activity was measured using five in vitro spectrophotometric methods: 1,1-diphenyl- 2-picrylhydrazyl radical scavenging activity (DPPH), 2,2'-azino-bis (3-ethylbenzthiazoline- 6-sulphonic acid) radical cation scavenging activity (ABTS), ferric reducing-antioxidant power (FRAP) and reduction power (RP)Fe(III) to Fe(II). Obtained results showed that anthocyanins, predominantly of cyanidin-3-O-galactoside, are the major class of polyphenolic compounds in tea infusions. Among phenolic acids the most abundant is caffeic acid. A significant correlation between DPPH and ABTS and FRAP and RP suggested that antioxidant components in these beverages were capable scavenging free radicals and reducing oxidants. Generally, these beverages had relatively high antioxidant capacities and could be important dietary sources of antioxidant phenolics for the prevention of diseases caused by oxidative stress.

scholarly journals A Comparative Assessment on Antioxidant and Phytochemical of Trichilia monadelpha (Thonn) J.J. De Wilde (Meliaceae) Plant Extracts

2021 ◽  
pp. 24-33
Author(s):  
P. D. Clark ◽  
E. Omo-Udoyo
Keyword(s):  
Antioxidant Activity ◽  
Vitamin C ◽  
Plant Extracts ◽  
Methanol Extract ◽  
Methanolic Extract ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Scavenging Activity ◽  
Hydroxy Radical ◽  
Reducing Ability

This study was designed to evaluate the phytochemical screening and antioxidant activities of Trichilia monadelpha plant extracts. The leaves were extracted using two different solvents namely-(n-hexane and methanol).  The dry or wet yield of n-hexane extract was 1.3%, while methanolic extract exhibited a percentage yield of 3.7 %.  Phytochemical research revealed the presence of secondary plant metabolites such as; alkaloids, flavonoids, cardiac glycosides, terpenoids and saponins. In-vitro antioxidant activity was determined using three assays (DPPH free radical scavenging assay, reducing ability and hydroxy radical scavenging activity) with four concentrations (0.25, 5.0, 1.0 and 2.0 mg/L), vitamin C was also used as a standard antioxidant. The percentage of inhibition was measured, and the results from all assay models showed a concentration-dependent percentage of inhibition by the methanol extract. However, the percentage values for the 2,2, -diphenyl-1-picrylhydrazyl (DPPH), reducing ability and hydroxy radical scavenging activity assays of T. monadelpha leaf was lower than that of standard vitamin C. The Pearson’s correlation coefficient was evaluated and the results showed that of the two extracts, the methanolic extract had the most antioxidant activity with the methanol extract exhibiting a better significant correlation that had a similar trend to that of the antioxidant compound (vitamin C). The results of this study have shown that the plant Trichilia monodelpha contains bioactive compounds which may have contributed to its antioxidant properties.

scholarly journals Comparative Polyphenolic Content and Antioxidant Activities of Some Wild and Cultivated Blueberries from Romania

2011 ◽  
Vol 39 (2) ◽  
pp. 70 ◽  
Author(s):  
Andrea BUNEA ◽  
Olivia Dumitrita RUGINA ◽  
Adela M. PINTEA ◽  
Zoriţa SCONŢA ◽  
Claudiu I. BUNEA ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Radical Scavenging ◽  
Vaccinium Corymbosum ◽  
Hydrogen Atom Transfer ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Anthocyanin Content ◽  
Total Flavonoids ◽  
Total Polyphenols ◽  
Reducing Ability ◽  
Total Anthocyanins

Two wild and three cultivated blueberry varieties (‘Elliot’, ‘Bluecrop’ and ‘Duke’) from Romania were analyzed comparatively in order to determine the total polyphenols, total anthocyanins, total flavonoids content and measuring the antioxidant activity using three different single electron transfer-based assays, Trolox equivalent antioxidant capacity (ABTS), ferric reducing ability (FRAP), 2,2-diphenylpicrylhydrazil radical scavenging capacity (DPPH) and one hydrogen atom transfer-assay, oxygen radical absorbance capacity (ORAC). Total polyphenols content ranged from 424.84 - 819.12 mg GAE/100 g FW, total flavonoids ranged from 84.33-112.5 mg QE /100 g FW and total anthocyanins ranged from 100.58-300.02 C3GE/100g FW. The anthocyanins were separated and quantified using RP-HPLC-DAD. In Vaccinium myrtillus, petunidin-3-glucoside and delphinidin-3-glucoside have the highest contribution to the anthocyanin content while in Vaccinium corymbosum, peonidin-3-galactoside represent the major anthocyanin. Except for ORAC assay (r=0.765), all antioxidant activity values obtained were highly correlated with total polyphenol content (0.923≤ r ≤0.986). Wild blueberries had higher total polyphenols content and also antioxidant activity compared with cultivated ones.

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