For DPPH, total antioxidants and lipid peroxidation assay which control to use: Gallic acid or Ascorbic acid?
i think for DPPH assay gallic acid or ferulic acid will be the best standard for FRAP assay you can use asorbic acid and for beta-carotene-linoleic acid assay butylated hydroxy toulene will the standard
Use gallic acid instead of ascorbic acid. A known concentration (mM) of GA should react better than an equal conc of AsA. But more preferably, use catechin (another antioxidant) if you have it. Catechin reacts quite better. See literatures for further convinction (if need be).
Gallic acid. Ascorbic acid is too unstable and could be prooxidant.
I found it easier to make ascorbic acid standards rather than gallic acid standards. Ascorbic acid standards gave me pretty good results than that of gallic acid. Is it because of the presence of ethanol in making the gallic acid standards?
Use Gallic acid. For lipid peroxidation assay we can't able to use ascorbic acid because it acts as a pro-oxidant.
Ascorbic acid, alpha-tocopherol and BHT are usually common used for antioxidant experiments that including your. If you are considering about Ascorbic acid or Gallic acid, You should use ascorbic acid. There are so many article already public using ascorbic acid as positive control. Be happy
Ascorbic acid gives better result than gallic acid,mainly gallic acid is used for determination of phenolic content as standard.Ascorbic acid used as standard with DPPH method.
I agree with the colleagues who suggest Trolox as a standard. Ascorbic acid sometimes reacts as pro-oxidant.
see my article for details.... Estimation of antiradical capacity..you can get it from my page..
Ascorbic acid is can be easily procured and also it give best results, So, it fits well for as Standard and then Gallic Acid is best secondly.
DPPH assay involves radical reaction and usually measured in terms of percentage decrease in absorbance. The absorbance of pure DPPH solution by itself keeps on decreasing with time. It is therefore important to choose a positive control which has faster reactivity and gives sharp decrease in absorbance in short span of time. Ascorbic acid gives a better response and in very faster in reactivity hence a stable absorbance value comes after a short span of time say 15 min. Plant polyphenols which contribute towards antioxidant potential are weaker in reactivity and require more time to give a stable response. Therefore a particular time of measurement should be set for both control and samples say 30 min. for optimal response.
Yes I agree with Deepshikha Gupta that ascorbic acid is a better standard than garlic acid for DPPH assay. Trolox equally gives rapid and reproducible response in the DPPH assay
Ascorbic acid can be used as standard to compare Sir Jyoti Prasad Saikia is right . Gallic acid may cause several side effects.
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