New Method Released to Determine In vivo Antioxidant Status

Posted on: May 15th, 2013 by or@c 4 Comments

New Method Released to Determine In vivo Antioxidant StatusA nonfluorescent probe has been used which, after being oxidized by reactive oxygen species present in serum samples, was transformed into a form that emitted fluorescence. By quantifying the specific fluorescence, the scientists were able to measure the reactive oxygen species concentration which does not discriminate between the various free radicals found in the human body. Thus this assay can be very useful in quantifying total reactive oxygen species in vivo.

Read more:    http://dx.doi.org/10.5099/aj130200154

4 Responses

  1. T Rigby says:

    Can you please tell me what is the difference between ORAC Capacity and Total ORAC – if a product has many different antioxidant components can it be compared to a product with less ingredients ? Does the weight/amount of individual ingredients make a difference to the Total ORAC

    • or@c says:

      Total ORAC historically has been used in reference to different entities. The term has been used to refer to the sum of hydrophilic and lipophilic antioxidant capacity using the peroxyl radical in a given sample. More recently, he term has been used to refer to the the sum of the antioxidant capacity using different free radical sources. Assays are currently available for up to 6 different radical/oxidant sources. However, it should be clearly indicated in any “total” ORAC value what is being included in the “total” number in comparison of different samples. The value of evaluating different radical sources is that different ingredients may have differing antioxidant capacity against different radical sources and a combination may be of more value than a single or smaller number of ingredients. However, care must be exercised in comparing as a “total” may not be the best representation of the antioxidant capacity in a mixture. In all of the assays, the antioxidant capapcity should be expressed on a weight basis of the product or components.

  2. Marchese says:

    We’re developping a new High Orac product and we would compare difeerent methods for test

    • or@c says:

      I would recommend that you consider using ORAC using different radical sources currently referred to as ORAC5.0 on the website since these multiple tests evaluate the antioxidant capacity against different radical sources. Any new product developed should hopefully have antioxidant capacity against several of the radicals and not just one of them. ORAC using just the peroxyl radical can be used in development to test effects of processing, etc, but at some point one needs to look at the antioxidant capacity against several radical sources.

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