Journal ArticleDOI
Use of a Free Radical Method to Evaluate Antioxidant Activity
Reads0
Chats0
TLDR
The antiradical properties of various antioxidants were determined using the free radical 2,2-Diphenyl-1-picrylhydrazyl (DPPH*) in its radical form as discussed by the authors.Abstract:
The antiradical activities of various antioxidants were determined using the free radical, 2,2-Diphenyl-1-picrylhydrazyl (DPPH*). In its radical form. DPPH* has an absorption band at 515 nm which dissappears upon reduction by an antiradical compound. Twenty compounds were reacted with the DPPH* and shown to follow one of three possible reaction kinetic types. Ascorbic acid, isoascorbic acid and isoeugenol reacted quickly with the DPPH* reaching a steady state immediately. Rosmarinic acid and δ-tocopherol reacted a little slower and reached a steady state within 30 min. The remaining compounds reacted more progressively with the DPPH* reaching a steady state from 1 to 6 h. Caffeic acid, gentisic acid and gallic acid showed the highest antiradical activities with a stoichiometry of 4 to 6 reduced DPPH* molecules per molecule of antioxidant. Vanillin, phenol, γ-resorcylic acid and vanillic acid were found to be poor antiradical compounds. The stoichiometry for the other 13 phenolic compounds varied from one to three reduced DPPH* molecules per molecule of antioxidant. Possible mechanisms are proposed to explain the experimental results.read more
Citations
More filters
Journal ArticleDOI
Standardized Methods for the Determination of Antioxidant Capacity and Phenolics in Foods and Dietary Supplements
TL;DR: Methods available for the measurement of antioxidant capacity are reviewed, presenting the general chemistry underlying the assays, the types of molecules detected, and the most important advantages and shortcomings of each method.
Journal ArticleDOI
Polyphenols: Chemistry, Dietary Sources, Metabolism, and Nutritional Significance
TL;DR: An overview of the nutritional effects of the main groups of polyphenolic compounds, including their metabolism, effects on nutrient bioavailability, and antioxidant activity, is offered, as well as a brief description of the chemistry ofpolyphenols and their occurrence in plant foods.
Journal ArticleDOI
Comparison of ABTS, DPPH, FRAP, and ORAC assays for estimating antioxidant activity from guava fruit extracts
TL;DR: Guava fruit extracts were analyzed for antioxidant activity measured in methanol extract and dichloromethane extract (AOAD), ascorbic acid, total phenolics, and total carotenoids contents.
Journal ArticleDOI
Antioxidant activity and phenolic compounds of 112 traditional Chinese medicinal plants associated with anticancer.
TL;DR: Traditional Chinese medicinal plants associated with anticancer might be potential sources of potent natural antioxidants and beneficial chemopreventive agents, and contain significantly higher levels of phenolics than common vegetables and fruits.
Journal Article
The use of the stable free radical diphenylpicrylhydrazyl (dpph) for estimating antioxidant activity
TL;DR: The use of the stable free radical diphenylpicrylhydrazyl (DPPH) for estimating antioxidant activity and its application in antioxidant research is described.
References
More filters
Book ChapterDOI
Natural Antioxidants Exploited Commercially
TL;DR: The object of this chapter is to provide information on natural antioxidants commercially exploited, including their manufacture, some physical and chemical properties, methods of application and their efficacy.
Journal ArticleDOI
Studies on Inhibition Mechanism of Autoxidation by Tannins and Flavonoids. V. Radical-Scavenging Effects of Tannins and Related Polyphenols on 1, 1-Diphenyl-2-picrylhydrazyl Radical
Takashi Yoshida,Kazuko Mori,Tsutomu Hatano,Tomoko Okumura,Ikue Uehara,Keiko Komagoe,Yuzaburo Fujita,Takuo Okuda +7 more
TL;DR: In this paper, the effects of tannins and related polyphenols on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical were evaluated by colorimetry.
Book ChapterDOI
Recent Trends in Food Applications of Antioxidants
TL;DR: In this paper, the authors discuss the important trends of the past seven years in applications of antioxidants in foods and discuss the use of commonly added synthetic antioxidants and four naturally occurring ones, namely α-tocopherol and ascorbic.
Journal ArticleDOI
The kinetics of reaction of 2,2-diphenyl-1-picrylhydrazyl with phenols
TL;DR: The kinetics of reaction between 2,2-diphenyl-1-picrylhydrazyl (DPPH) and a wide variety of phenols have been studied as mentioned in this paper.
Journal Article
[Rosmarinic acid, total hydroxycinnamic derivatives and antioxidant activity of Apiaceae, Borraginaceae and Lamiceae medicinals].
TL;DR: A number of medicinal species of the Apiaceae, Borraginaceae and Lamiaceae families present high rosmarinic acid and total hydroxycinnamic derivative contents.