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Organic Wine Terms
Sulfites:
What are they and what do they do?
Key Differences Found Between Organic
and Conventional Red Wines
Recent evidence has suggested that
moderate consumption of red wine results
in a decreased risk of cardiovascular
disease. This is attributed to the
antioxidant effect of the polyphenolic
compounds in red wines. The major
antioxidant in red wines – resveratrol –
is a stilbene shown to have anticancer
effects.
However, wines have also been shown to
be contaminated with ochratoxin A (OTA),
a mycotoxin that is widespread in
foodstuffs including cereals, coffee,
walnuts, milk, and pork meat. The
European Scientific Committee for Food
defines OTA as “a mycotoxin having
carcinogenic, nephrotoxic, teratogenic,
immunotoxic, and probably neurotoxic
effects.” Attempts have been made to
clarify what level of OTA consumption is
safe, with estimates ranging from 0.5-10
micrograms per kilogram (parts per
billion).
This study examines 15 different red
wines – five table wines, four
Controlled Denomination of Origin
(Denominazione di origine controllata,
or DOC), and six organic wines.
Researchers (Micelli et al., 2003)
looked at the levels of polyphenolic
compounds, resveratrol, antioxidant
activity, and ochratoxin A (OTA)
contamination.
Organic and DOC wines were found to have
significantly higher levels of total
polyphenols. DOC wines had the greatest
total polyphenols, averaging 2,148
mg/liter (parts per million). An organic
wine was shown to have the highest total
polyphenols of all 15 varieties studied,
2,540 mg per liter, 30% higher than the
average total polyphenols in table
wines.
Resveratrol and antioxidant activity
were both were found to be highest in
the organic wines. In terms of
resveratrol levels, the organic wines
averaged 1.69 mg per liter (parts per
million), while DOC and Table wines
averaged 1.16 and 1.18 mg per liter
respectively. The organic wines tested
were found to have the greatest
antioxidant activity, averaging 13.6
percent (percentage of Beta-carotene
protection against oxidation). Table
wines had on average 50 percent less
antioxidant activity than organic and
DOC wines.
Of the three types of wine, only the
organic wines showed a significant
difference in OTA contamination. OTA
contamination in six organic wines
averaged 0.14 micrograms per liter
(parts per billion), while the four DOC
wines averaged 0.45 micrograms per liter
and the five table wines were 0.38
micrograms per liter.
This study found that among 15 varieties
of red wine, organic wines had the
greatest concentrations of antioxidant
activity and of the key antioxidant
resveratrol. An organic wine also was
found to have the highest level of total
polyphenols. Contamination of the
mycotoxin OTA was over three times
higher in conventionally grown DOC
varieties compared to organic wines, and
the OTA levels in table wines were 2.5
times higher that organic red wines.
The study found that the combination of
farming practices used by organic grape
growers reduced the risk of mycotoxin
formation, through an as yet
unidentified mechanism. In the Organic
Center’s State of Science Review on
mycotoxins, two possible explanations
are discussed:
Lower levels of nitrogen in organic
systems tends to reduce fungal growth;
and
Generally higher levels of antioxidants
in organic grapes protects fruit from
mycotoxin-forming fungi.
Source: “Polyphenols, resveratrol,
antioxidant activity, and ochratoxin A
contamination in red table wines,
Controlled Denomination of Origin (COD)
wines and wines obtained from organic
farming.”
Authors: Antonio Micelli, Carmine Negro,
Luca Tommasi and Pietro de Leo, Journal
of Wine Research, Volume 14, Number 2-3,
December 2003.
This
document was provided
by Organic Vintners
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