scholarly journals Determination of antiradical and antioxidant activity: basic principles and new insights.

2010 ◽  
Vol 57 (2) ◽  
Author(s):  
Gunars Tirzitis ◽  
Grzegorz Bartosz
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Basic Principles ◽  
Definition Of

Although the term 'antioxidant' is used very frequently, there are problems with the definition of antioxidants and estimation of antioxidant activity. The distinction between antioxidant and antiradical activities is not always obvious. This minireview discusses critically the principles, advantages and limitations of the most frequently used methods of estimation of antiradical and antioxidant activities.

A Relationship between the Critical Oxidation Potentials and Antioxidant Activities of Rubber Antioxidants

1939 ◽  
Vol 12 (2) ◽  
pp. 287-291 ◽  
Author(s):  
C. M. Doede
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Optimum Range ◽  
Oxidation Potentials ◽  
A Value ◽  
Physico Chemical ◽  
Sole Criterion

Abstract 1. According to the data presented, all of the compounds tested which exhibit marked antioxidant activity have an Ec value between 0.65 volt and 0.90 volt. Many substances exist which have an Ec value within the optimum range, but do not have much antioxidant activity. The condition that the Ec value for a good antioxidant falls between 0.65 volt and 0.90 volt seems to be necessary but not sufficient. 2. A value of Ec within an optimum range seems to be only one of several possible physico-chemical phenomena which govern the rubber antioxidant activity of a compound. 3. The determination of the Ec value of a compound should not be used as the sole criterion of that compound's antioxidant activity.

scholarly journals CHEMICAL CONSTITUENTS, IN VITRO ANTIOXIDANT ACTIVITY, ORAL ACUTE TOXICITY AND LD50 DETERMINATION OF MORINGA OLEIFERA LEAVES

2017 ◽  
Vol 9 (5) ◽  
pp. 240
Author(s):  
Manal Mortady Hamed ◽  
Aboelfetoh Mohamed Abdalla ◽  
Mosad Ahmed Ghareeb ◽  
Said Abdelhalim Saleh
Keyword(s):  
Antioxidant Activity ◽  
Acute Toxicity ◽  
Antioxidant Activities ◽  
Total Phenolic ◽  
Dry Extract ◽  
Phenolic Contents ◽  
Moringa Oleifera Leaves ◽  
Oral Acute Toxicity

Objective: The objective of this study was undertaken to estimate the total phenolic contents (TPCs), in vitro antioxidant of different solvent extracts of M. oleifera leaves, oral acute toxicity and LD50 determination of the 85% methanolic extract as well as the chromatographic isolation and identification of the extract constituents.Methods: The antioxidant activity of different solvent extracts of Moringa oleifera leaves were estimated using three antioxidant assays and the total phenolic contents (TPCs) were also evaluated using Folin-Ciocalteu’s assay. The n-BuOH extract undergoes further chromatographic isolation owing to the high antioxidant activity using 2, 2'-diphenyl-1-picrylhydrazyl radical (DPPH) method, which resulted in the isolation of seven compounds.Results: The results showed that the TPCs values of the tested extracts were varied from 309.52 to 43.28 mg gallic acid equivalent/g dry extract. The reducing power antioxidant activities (RPAA) were 0.434, 0.402, 0.395, 0.149, 0.143 and 0.124, while the total antioxidant capacity (TAC) values were 316.43, 203.35, 181.56, 86.70, 76.62 and 50.83 mg ascorbic acid equivalent/g dry extract; for n-BuOH, EtOAc, 85% MeOH, H2O, CH2Cl2, and pet. ether extracts, respectively. The oral acute toxicity study of the 85% methanol extracts of M. oleifera and M. peregrina revealed that; their LD50 values were 3458.3 and 4125 mg/kg respectively, thus the two plants could be classified as slightly toxic in the scale of Hodge and Sterner which reflected their nutrient values as edible plants. The isolated compounds were identified on the basis of their 1H and 13C-NMR spectra as; cis-p-coumaric acid 4-O-(2'-O-β-D-apiofuranosyl)-β-D-glucopyranoside (1), chlorogenic acid (2), niazirin (3), 3,4-dihydroxy-β-phenylethoxy-O-α-L-rhamnopyranosyl-(l→2)-α-L-rhamnopyranosyl-(1→3)-4-O-caffeoyl-β-D-glucopyranoside (4), gallic acid (5), taxifolin (6), and benzyl-carbamo-thioethionate (7).Conclusion: The M. oleifera leaves showed promising antioxidant activities and slightly toxic behavior.

scholarly journals Determination of Phenolic Compounds and Antioxidant Activity in Vegetables Consumed in Mekelle Tigray Ethiopia

2016 ◽  
Vol 4 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Teklit G. Amabye ◽  
Frehiwot Mekonen
Keyword(s):  
Antioxidant Activity ◽  
Phenolic Compounds ◽  
Phenolic Content ◽  
Antioxidant Activities ◽  
Research Studies

Vegetables are widely consumed in Mekelle and imported from different regions and zones of the countries. This study was performed to evaluate the phenolic content and antioxidant activity of vegetables commonly consumed in Mekelle. Kale, carrot, cabbage and barcoli were used in the study. This research studies in detail the contents of phenolic compounds determined by the Folin−Ciocalteu reagent and the antioxidant activities determined by DPPH (using diphenyl-p-picrylhydrazyl radical). Among all vegetables kale showed highest phenolic content followed by barcoli, cabbage and carrot   and the highest antioxidant activity were barcoli followed by kale, cabbage and carrot   which was expressed in % of DPPH consumption after 30 minutes of reaction.  The data shows the importance of antioxidant activity of vegetables in the diet. 

scholarly journals Analytical characterization of some pasteurized apple juices during storage

2015 ◽  
Vol 26 (1) ◽  
pp. 7-11
Author(s):  
Cristina Damian ◽  
Ana Leahu ◽  
Mircea Oroian ◽  
Sorina Ropciuc
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Activity Levels ◽  
Total Antioxidant Activity ◽  
Ascorbic Acid Concentration ◽  
Rotational Viscometer ◽  
Total Antioxidant ◽  
Radical Method

AbstractThe aim of the study was to assess the effect of three weeks of storage on the chemical and rheological properties of apple juices obtained from Idared and Jonatan apples variety. Total antioxidant activity, levels of bio-active compound groups and the viscosity were measured to characterize the investigated juices. The method applied for the determination of ascorbic acid concentration was with 2, 6-diclorophenolindophenol. Total phenols (TP) in apple juices were determined using the Folin-Ciocalteau method and antioxidant activity by the use of DPPH free radical method. The viscosity of apple juices was investigated by a rotational viscometer, Brookfield viscometer (Brookfield Engineering Inc., Model RV-DV I Prime) with RV spindles. During three weeks of storage, different rates of all measured properties have been observed decreasing for both studied apples varieties juices. The juices from Jonatan apples have higher antioxidant activities that are correlated with the higher content in polyphenols and lower values of viscosity.

scholarly journals Uji Aktivitas Antibakteri dan Antioksidan Ekstrak Pigmen Klorofil Rumput Laut Caulerpa racemosa (Forsskal) J.Agardh

2018 ◽  
Vol 3 (2) ◽  
pp. 53-58
Author(s):  
Lisiard Dimara ◽  
Tien Y.B Yenusi
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antioxidant Activity ◽  
Key Words ◽  
Antioxidant Activities ◽  
Caulerpa Racemosa ◽  
Chlorophyll Pigment ◽  
Paper Disc

The determination of antimicrobial and antioxidant activities of Chlorophyll pigment of Caulerpa racemosa (Forsskal) J.Agardh is described in this study. The aim of the study was to find out the effectiveness of chlorophyll extract in inhibiting growth of Staphylococcus aureus and Escherichia coli. Paper disc method was used to study the hampering the ability of chlorophyll toward both bacteria, and the DPPH (1,1-difenil-2-dipikrilhidrazil) method was used to find out the antioxidant activity. The result showed that extract chlorophyll can inhibit the growth of both bacteria at the concentration of 100% with the inhibition diameter zone 2.170 cm and 2.100 cm respectively. Whereas the IC50 of the chlorophyll is 2350.3 ppm can be served as an antioxidants.   Key words: antibacterial, antioxidants, chlorophyll, Caulerparacemosa (Forsskål) J.Agardh.

scholarly journals Determination of Multiple Antioxidant Activities of Endemic Tricholoma anatolicum H.H Doğan & Intini Collected from Turkey

2018 ◽  
Vol 6 (11) ◽  
pp. 1582 ◽  
Author(s):  
Hatıra Taşkın ◽  
Tülin Eker ◽  
Fuat Bozok ◽  
Hasan Hüseyin Doğan ◽  
Saadet Büyükalaca
Keyword(s):  
Antioxidant Activity ◽  
Methanol Extract ◽  
Antioxidant Activities ◽  
Far East ◽  
Reducing Power ◽  
Total Phenolic ◽  
Mushroom Species ◽  
Antioxidant Power ◽  
Ferric Reducing Antioxidant Power

Tricholoma anatolicum H.H. Doğan & Intini is known as the most prized mushroom species in Feke region of Turkey. This mushroom species is collected from Cedar (Cedrus libani) forests and therefore is named as Cedar mushroom in this region. It is collected and consumed by local collectors and also exported to Far East countries such as Japan by exporting companies. Therefore, it is important to investigate the nutritional and medical importance of this species. The aim of this study is to reveal the antioxidant activity of methanol extract in different concentrations (1, 2 and 4 mg/mL) of T. anatolicum H.H. Doğan & Intini collected from Feke district of Adana province of Turkey in 2015. In this study, it was determined that total phenolic content of this mushroom was 56 mg/kg. 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO) and reducing power (RP) activities given in trolox (µM) and ferric-reducing antioxidant power (FRAP) given in FeSO4 (µM) were found as 449, 180, 337 and 2 at the highest concentration (4 mg/mL), respectively. As a result, it could be suggested that methanol extract of T. anatolicum H.H. Doğan & Intini has significantly antioxidant activity.

scholarly journals Optimization Of Microwave-Assisted Extraction Of Flavonoids From Binahong (Anredera cordifolia) Leaves Using Respon Surface Methodology

2020 ◽  
Vol 7 (3) ◽  
pp. 10-19
Author(s):  
Zaldy Rusli ◽  
Bina Lohita Sari ◽  
Novi Fajar Utami ◽  
S Sabila
Keyword(s):  
Antioxidant Activity ◽  
Ethanol Concentration ◽  
Antioxidant Activities ◽  
Extraction Process ◽  
Extraction Time ◽  
Microwave Assisted Extraction ◽  
Optimum Conditions ◽  
Microwave Assisted ◽  
Assisted Extraction

Binahong (Anredera scandens (L.) Moq.) leaves are one of the plants that empirically can be used for wound healing and contain flavonoids which have antibacterial and antioxidant activities. Determination of the optimum conditions of the Binahong leaf extraction process needs to be done to ensure the extraction quality of the Binahong leaves associated with the given activity. Microwave Assisted Extraction (MAE) is an extraction that utilizes microwave radiation to heat the solvent quickly and efficiently. This study aims to determine the most effective binahong leaf extraction conditions that produce optimal levels of flavonoids and antioxidant activity. The extraction process was carried out using the Microwave assisted extraction (MAE) method. Determination of optimum conditions is done based on Response Surface Method (RSM) with variable ethanol concentration (70%, 80% and 90%), extraction time (4, 12 and 20 minutes) and power (450, 600, and 800 watts) using Box- Behnken Design (BBD) with Design Expert 7.0 software. The extract quality parameters measured were total flavonoid levels and antioxidant activity. The results showed the optimum conditions with the BBD method were obtained at an ethanol concentration of 81.49%, extraction time of 13.84 minutes, and power of 626.19 watts with flavonoid levels of 3.8561% and antioxidant activity (IC50) of 95.51834 ppm with active categories.

scholarly journals Akseptabilitas Es Krim dengan Fortifikasi Mesocarp Lontar (Borassus flabeliffer L.) sebagai Antioksidan dan Serat Pangan Alami

2019 ◽  
Vol 38 (3) ◽  
pp. 251
Author(s):  
Eny Idayati ◽  
Agrippina Agnes Bele ◽  
Rikka Welhelmina Sir
Keyword(s):  
Antioxidant Activity ◽  
Dietary Fiber ◽  
Antioxidant Activities ◽  
Radical Scavenging ◽  
Stable Condition ◽  
Ice Cream ◽  
Beta Carotene ◽  
Carotene Content ◽  
Wet Weight

Lontar palm (Borassus flabeliffer L.) fruit is one of the specific tropical fruits from East Nusa Tenggara province (NTT)-Indonesia that is rich in functional compounds such as beta-carotene as an antioxidant and food fiber.  However, the utilization of these fruits is still limited due to the streroidal saponins and pholifenol content that makes them taste bitter and less favored by consumers. Therefore, one alternative that can be done is by enriching them into ice cream products. The production of Ice cream cannot go through with high heating processing so that the antioxidants extracted from lontar palm mesocarp can be in a stable condition. The aim of this study is to investigate the effect of ice cream on the acceptability values of the hedonic test, determining of fiber and beta-carotene content and evaluating antioxidant activities fortification from the lontar's mesocarp. The amount of lontar mesocarp for fortification (F) were 30%, 40% and 50% of the wet weight with the combination of some variation of milk treatment such as full cream milk, sweetened condensed milk, and liquid soy milk. The acceptability of the product was tested using hedonic test against color, aroma, texture, and flavor parameter. Antioxidant activity was performed by determination of the DPPH value (1.1-diphenyl-2picryhydrazil radical-scavenging), dietary fiber using enzymatic-gravimetric methods and UV-Vis spectrophotometers to analyze the content of beta-carotene. The results showed that on the acceptability test, the most preferred samples valued by panelists were the fortification, F1 treatment  (30%) with the content of β-carotene of full cream milk was 2212.44 ± 11.82 μg /100 mg, dietary fiber was 8.95 ± 0.05%, and antioxidant activity was 45.54 ± 0.36%.

Determination of Antioxidant Activity in Foods and Beverages by Reaction with 2,2′-Diphenyl-1-Picrylhydrazyl (DPPH): Collaborative Study First Action 2012.04

2012 ◽  
Vol 95 (6) ◽  
pp. 1562-1569 ◽  
Author(s):  
David W Plank ◽  
John Szpylka ◽  
Harry Sapirstein ◽  
David Woollard ◽  
Charles M Zapf ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Water Solution ◽  
Collaborative Study ◽  
Colorimetric Method ◽  
Reaction Medium ◽  
Pomegranate Juice ◽  
Omega 3 ◽  
Two Samples

Abstract A colorimetric method for the determination of total antioxidant activity in a variety of foods and beverages was validated in both a single-laboratory validation and a collaborative laboratory validation study. The procedure involved extraction of the antioxidants directly into a methanol–water solution containing a known amount of 2,2′-diphenyl-1-picrylhydrazyl (DPPH), thus promoting the rapid reaction of extracted materials with DPPH. The reaction was monitored by spectrophotometric measurement of the absorbance loss at 517 nm. Antioxidant activity was quantified relative to a dilution series of vitamin E analog standards (Trolox®), which were analyzed in parallel simultaneously with the food and beverage samples. The antioxidant activities of the samples ranged from 131 to 131 000 μmole Trolox equivalents/100 g. Statistical analysis of the results showed that nine of the 11 matrixes gave acceptable HorRat values, indicating that the method performed well in these cases. The acceptable matrixes include pomegranate juice, blueberry juice, carrot juice, green tea, wine, rosemary spice, ready-to-eat cereal, and yogurt. Two samples failed the HorRat test: the first was an almond milk that had an antioxidant level below the practical LOQ for the method; the second was a sample of canola oil with added omega-3 fatty acid that was immiscible in the reaction medium.

scholarly journals Antioxidant Acitivity in Various Processed Products of Inferior Local Tubers (Dioscorea sp. L.)

2017 ◽  
Vol 3 (5) ◽  
pp. 35
Author(s):  
Ari Yuniastuti ◽  
Retno Sri Iswari ◽  
R. Susanti
Keyword(s):  
Antioxidant Activity ◽  
Bioactive Compounds ◽  
Antioxidant Activities ◽  
Different Types ◽  
Processed Products ◽  
Wild Yam

<p>Inferior local tubers such as lesser yam, wild yam and arrowroot contain bioactive compounds such as phenols and diosgenin which act as antioxidants.  Antioxidant activities in the processed of local tubers have not been reported. The aim of this research was to identify the antioxidant activity of local tubers (inferior) that has been processed through the process of steaming, frying and milling to be flour. The determination of antioxidant activity was performed using α, α, Diphenyl Picryl Hydrazil (DPPH), which is indicated as a percentage of the apprehension of radical activities by the amount of absorbance at 680 nm. The antioxidant activity of lesser yam steamed, fried and milled were 2.26 %, 0.84 %, and 3.34 % respectively. The antioxidant activity of steamed, fried and milled arrowroot were 1.44 %, 0.65 %, and 1.32 % respectively. Moreover, the antioxidant activity of steamed, fried and milled wild yam were 1.08 %, 0.08 %, and 0.82 % respectively. The antioxidant activity of inferior local tubers have decreased in different types of processing. The highest antioxidant activity was in the milled tubers followed by steamed and fried tuber. </p>

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