246
In an accurate evaluation of the total antioxidant ca-
pacity, the antioxidant properties of single molecules
present in a single product, but also the synergic ef-
fects of interactions between the different bioactive
compounds may be considered. In addition, we have
studied the relative contributions of vitamin C and
phenolic compounds to the antioxidant potential of
fruits and vegetables. In Table 3, the FRAP values
have been shown and have been compared to values
derived from literature data (9, 15).
The antioxidant capacity often could be linearly cor-
related with the phenolic content. So we have eval-
uated the content of most representative molecules
in every selected product (Table 4) and we have re-
lated it to literature data (16,17, 18, 19, 20).Fruits
Apple polyphenols have been widely observed; cin-
namic acid derivatives, flavonols and anthocyanins,
compounds with strong antioxidant activity, have
been found mainly in cortex and in skin (21). The
FRAP values for apple with peel was 7.65 mmolkg-
1 (SD 0.49) and for apple without peel was 4.15
mmolkg-1 (SD 0.07). In particular, the contribution of
lipophilic fraction was more than hydrophilic frac-
tion for both apple with peel and apple without peel.
According to our results, the value of the total an-
tioxidant power, obtained for apples, should be due
to contribution of flavonoids such as quercetin, epi-
catechin and procyanidin B(2) rather than vitamin C.
In addition we have calculated that the percentage
Table 3 .Ferric-reducing antioxidant power (FRAP) of selected food extracts.Mean total
Region Food
(mmol kg-1)SD Literature data
Abruzzo Raw carrot 0.9 3 0 .12 1. 06 c
Cooked carrot 0. 8 0. 02
Apple with peel 7.6 5 0 .4 9 7.4c
Apple without peel 4.15 0 .07 3 .2 3 c
Calabria Chicory 20. 36 0 .0 8
Strawberry (cultivated) 17.79 0 .43 22.74c
Lazio Chicory (cultivated) 4.61 0 .3 8
Chicory (wild) 7. 33 0. 36
Plums (cultivated) 9.8 0 0 .8 9
Plums (wild) 83 .8 6 1 4.7 3
Lombardia Strawberry (wild) 62.85 3 .2 3 28.00c
Cherry 18. 55 1.91 8 .1 0 c
Piemonte Pear with peel 2.9 0 .28 5 .00c
Pear without peel 1.3 5 0. 07
Raw potatoa 2. 6 0 3 .67c
Cooked potatoa 3 .9 5 0 .2 1
Raw potatob 2.6 0 .14 3 .67c
Cooked potatob 4. 4 0 .7 1
Veneto Raw potato Rotzo 3.05 0 .64 3 .67c
Cooked potato Rotzo 4. 3 0 .1 4
Raspberry 57. 7 6. 2 43 .0 3 c
aOrganic cultivation.
bIntegrated cultivation.
cData from Pellegriniet all. Mol Nutr Food Res 50:1030 – 1038 (2006).
dData from Khanizadehet al.JFAE 5: 61-66 ( 2007 ).