Are there anyone using FRAP, DPPH or ABTS assay for measuring antioxidant activity in fresh vegetables?
Or do you have any suggestions about more practical,reliable methods?
thanks
Hi.
I would say you should try ORAC and DPPH. I find these two methods reliable.
Regards
Ankit.
I am working with DPPH and is good, but I think it is having some quirks. I am using also a method developed by Analytic Jena, with trolox for lipid soluble compounds and ascorbic acid for water soluble compounds on Photochem apparatus from them. It is not cheap, but the results are reproducible.
Hi,
FRAP, DPPH and ABTS are considered "wet chemistry" assays, they are quick, reliable (if performed in controlled conditions) and are commonly used, so it will be easier to compare your results with data in literature. No radicals are needed to be produced (DPPH and ABTS are radicals themselves), so it makes them easier to be performed in controlled conditions. However, ORAC and other methods (deoxyribose assay; b-carotene bleaching assay) need the production of radicals under the reaction conditions, which makes them more transferable to oxidation model systems in biological or food applications. In the lab where I work, we use FRAP and DPPH for crude extracts; and ORAC and other radical-based methods for fractions obtained from the crude extracts.
Regards
Apart from the anti-ox activity that is measured, it is crucial to know what chemicals are responsible for it. Therefore chemical characterization is a crucial annex to anti-ox activity testing.
I believe you should use the DPPH method. we usually use it for fresh food...
If you need any more details on the method itself I'll be happy to help you.
best wishes
No doubt, DPPH is fast, convenient and more stable method and our grop use this method for a range of plants and vegetable extracts. Antioxidants can deactivate radicals by two major mechanisms, hydrogen atom transfer (HAT) and single electron transfer (SET). HAT-based assays (FRAP) such as quantify hydrogen atom donating capacity and ET-based assays (DPPH and FRAP) measure an antioxidant’s reducing capacity. For more detailed information regarding antioxidat assay, please check this review. http://pubs.acs.org/doi/abs/10.1021/jf030723c.
DPPH and ORAC by ELISA seems to be very good measures as our lab records reveals.
Regards,
Torab Rahim
INFS, DU, Bangladesh
I am using FRAP and procedure based on using the Folin-Ciocalteu reagent (FCR) to determine antioxidant activity and total phenolic compounds (TPC) respectively. Methanol extracts of fruits and vegetables are being used for assay. The methods are good and reliable
All the best.
there is so much information more than I expected in such a short time! Really, Thanks.
I used the DPPH method in one of my postgraduate student's research. I think we also tried FeCl3 method. Find protocols and decide which one would be OK.
Thanks for introduce your methods and experience. We have used those methods except ORAC. My experience is that when you first use them, you should try several times to make your sample being at suitable concentration, and for some samples you should clean the interferent like pigment carefully.
I think that instrumentally measured antioxidant activity can not be regarded as equivalent antioxidant activity in the human
I would like to know if there are any composition tables for antioxidants in foods
Look at Dr. Alexander Schauss's book on acai. He has tables in the book.
DPPH assay only reflects water soluble antioxidants so FRAP assay is useful to get the total antioxidant power. It is also advisable to do the total phenolic contents to observe any correlation between total phenolics and antioxidant activities.
- Badges
- Science topic
- Similar topics
- Medicine
- Nutrition and Dietetics