Science Buddies: "Ask an Expert"

I have been doing a project with antioxidants and I have tried to find the ORAC levels for white tea and burdock root. Can anyone help? I need this information for my write-up.

Hi,

It seems difficult to find hard numbers for ORAC values, apparently due to lack of standard definitions of brewing conditios and test methods. There appears to be a consensus that white tea has a higher ORAC value than green tea, so values for green tea might give a lower bound to the number. Here are some relevant web lnks:

http://www.scielo.cl/scielo.php?pid=S07 ... ci_arttext

http://scholar.google.com.br/scholar?st ... R&as_sdt=0

http://www.sciencedirect.com/science?_o ... archtype=a

http://books.google.com/books?hl=en&lr= ... tea&f=true

http://www.jacn.org/cgi/reprint/21/1/1

Here is an FDA comparaative study of ORAC values by several methods for a set of fruits and vegetables:

http://ddr.nal.usda.gov/bitstream/10113 ... 633912.pdf

Here is a review of methods for determining antioxident activity:

http://sphinxsai.com/s_v2_n2/PT_V.2No.2 ... -1285).pdf

This document has a link to a table of antioxident values for more than 3100 products. I think this might be your best bet for the information you want. Ir lisrs antioxident concentrations, not ORAC results, and has green teas, but not white teas(they are the same plant though):

http://www.biomedcentral.com/content/pd ... 91-9-3.pdf

http://www.biomedcentral.com/content/su ... 9-3-S1.PDF]

I regret I can’t answer the question exactly as you asked it, but I doubt the question as asked is of much use to you for the reasons outlined in the links above. I hope this information is of use to you. If you have access to a library that can give you free online access to academic journals you can use Google Scholar to search for “ORAC assay of white tea” to find some articles that appear to have ORAC assay results of some white teas(unfortunately I don’t have free access).

I wish you every success with this project1!!!!

Best regards,

Barrett L Tomlinson

I checked out all of the sites that you listed. Thank you for trying to help me. I did not find exactly what I wanted, but it did help. The artical that I would have liked to have read was a pay for use site. I will have to ask my teacher about that.

Thank you for your help!