Champignons, een heel goede antioxidant.*
Bruine en kastanje champignons blijken net zo veel antioxidanten te bevatten dan andere goede voedselbronnen. In de studie werden de bioactieve stoffen polyfenolen zowel als ergothioneïnes onderzocht. Broccoli heeft wat deze stoffen betreft een ORAC waarden van 12, rode pepers 10, de kastanje champignon 9,7, de bruine champignon 9,5, de gewone (witte) champignon 6,9 en bijv. wortelen en sperziebonen hebben een waarde van 5. Alhoewel de ergothioneïnes in het menselijke lichaam een belangrijke bijdrage leveren blijkt uit de studie dat het vooral de polyfenolen zijn die de bescherming bieden tegen oxidatieschade.
Mushrooms
As Good An Antioxidant Source As More Colorful Veggies
Portabella
and crimini mushrooms rank with carrots, green beans, red peppers and broccoli
as good sources of dietary antioxidants, Penn State researchers say.
Dr. N. Joy Dubost, who recently earned her doctorate in food science at Penn
State, measured the activity of two antioxidants, polyphenols and ergothioneine,
present in mushrooms, using the ORAC assay and HPLC instrumentation, as part of
her dissertation research. She found that portabella mushrooms had an ORAC value
of 9.7 micromoles of trolox equivalents per gram and criminis had an ORAC value
of 9.5. Data available from other researchers shows carrots and green beans have
an ORAC value of 5; red pepper 10; and broccoli 12.
The ORAC assay, the most well known test of antioxidant capacity, focuses on the
peroxyl radical, the most predominate in the human body. Free radicals, such as
the peroxyl radical, are thought to play a role in the aging process and in many
diseases, including cancer, Alzheimer's and atherosclerosis. Epidemiological
studies have shown that those who eat the most fruits and vegetables rich in
antioxidants have lower incidence of these diseases.
Dubost detailed her results in a paper, Quantification of Polyphenols and
Ergothioneine in Cultivated Mushrooms and Correlation to Total Antioxidant
Capacity Using the ORAC and HORAC Assays, presented Monday, June 26, at the
Institute of Food Technologists meeting in Orlando, Fl. Her co-author is her
dissertation adviser, Dr. Robert Beelman, professor of food science.
Dubost explains that assays are a first step toward determining how effective a
food is in providing protection against oxidative damage. Anti-oxidants inhibit
increased rates of oxidation, which can damage proteins, lipids carbohydrates
and DNA.
She adds, "The ORAC assay does not tell what happens in the human body but
this assay is currently under investigation as to how it can predict
physiological activity."
The Penn State study showed that the anti-oxidant effect of mushrooms is due
primarily to the presence of polyphenols. Dubost and Beelman had earlier
identified mushrooms as an abundant source of the anti-oxidant, ergothionene.
Dubost notes, "Evidence suggests that erogothioneine is biologically very
important and, even though the assay used does not show it contributes to total
antioxidant activity in the mushrooms, it may significantly contribute
antioxidant activity in the body."
The ORAC values found in the latest study indicate that mushrooms are potent
anti-oxidant sources. The research revealed that, of the mushrooms tested,
portabella mushrooms and crimini mushrooms have the highest ORAC values.
Criminis, which are brown, are otherwise similar to the popular white button
mushroom, the one mostly commonly consumed in the U.S. The white button mushroom
has an ORAC value of 6.9, above tomato, green pepper, pumpkin, zucchini, carrot,
and green beans.
Dubost says, "You don't have to eat only the vegetables with the highest
anti-oxidant capacity to benefit. If you eat a variety of mushrooms along with a
variety of other vegetables, you'll be getting a variety of antioxidants."
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(
Juli 2006)