Agriculture Reference
In-Depth Information
tAble 13.3
Polyphenolic content of Red and white wine
Average Red wine
(mg/l)
Average white wine
(mg/l)
Gallic acid
95
7
Catechin
191
35
Caffeic acid
7.1
2.8
Epicatechin
82
21
Cyanidin
2.8
0
Malvidin-3-glucoside
23.5
1.0
Rutin
9.1
0
Myrcetin
8.5
0
Quercetin
7.7
0
Resveratrol
1.527
0.027
Source:
Frankel, 1995.
the literature on the influence of grape wine and tea polyphenols on atherosclerosis;
they concluded that the wine and tea polyphenols possess antioxidant activity and
may reduce total cholesterol, lower lipoprotein oxidation concentrations, and help
reduce chronic inflammation. Table 13.3 summarizes the bioactive polyphenolics
in wine as reported by Frankel et al. (1995). It is clear that the bulk of the phenolic
compounds are associated with red wine, most likely coming from the skins. Falchi
et al. (2006) demonstrated that flesh and skin of grapes had equivalent levels of tar-
taric acid, malic acid, shikimic acid, and
trans
caftaric acid; the flesh had slightly
lower levels of caffeic, p-coumaric, cinnamics, catechin, and epicatechin and were
approximately equal in providing cardioprotection.
Catechin in tea has been shown to strongly correlate with the antioxidant capac-
ity. Henning et al. (2003) showed a correlation between total catechin content and
antioxidant capacity. The authors presented a list of commercial tea products that
included a range of catechin contents from 204.7 mg/g tea to 0 catechin for some ice
tea products. Green tea ranged from 59.7 mg/g to 105.7 mg/g green tea. This clearly
points to a major issue with functional foods. Many functional foods are marketed
as containing green tea and other herbal supplements, but the labeling requirements
do not require a clear statement of the bioactives and how those might equate to a
cup of tea.
Many foods contain anthocyanins, which are likely beneficial at some level. Wu
et al. (2004) compiled an extensive list of anthocyanin content of fruits, vegetables,
nuts, dried fruit, spices, and other foods. This provides a useful baseline in determin-
ing how much of these components is consumed. One measure of the antioxidant
potential of a food is the oxygen radical absorbance capacity (ORAC). The method
provides a useful means to compare the potential of a food or ingredient to remove
oxygen radicals from a model system. The result is that foods can be compared for
