Results and discussion
The total phenolic contents in the pomace ethanolic extract and wine were measured according to the Folin-
Ciocalteu method. The Folin-Ciocalteu reagent determines total phenols (and other easily oxidized substances),
producing a blue colour by reducing yellow heteropolyphos phomolybdate-tungstate anions. This method gives a
general measure of phenolic content; however, it is not completely specific for any specific phenolic compounds and
not all phenolic compounds exhibit the same level of activity in the assay (Wu
et al
., 2006). The total phenolic
contents were determined from regression equation of calibration curve using gallic acid as a standard and expressed
as gallic acid equivalents (GAE).
From Table 1 and Fig. 1, the maximal total phenolic compounds was
Phyllanthus oxyphyllus
Miq. water
crude extract contained of 2,119.25±7.560
ȝ
gGAE/gdw (p<0.05) which was higher than the maximal ethanolic extract
of
Lagerstroemia speciosa
(L.) Pers. (1,282.75±6.182
ȝ
gGAE/gdw). The minimal total phenolic compounds was
Momordica charantin
L.
water crude extract (343±6.443
ȝ
gGAE/gdw). The significant correlations could be found
between the total phenolic content and antioxidant activity of the plant extracts in any of the studied subgroups. It is
known that different phenolic compounds have different responses in the Folin-Ciocalteu method. Similarily the
molecular antioxidant response of phenolic compounds depending on their chemical structure (Satue-Gracia
et al
.,
1997). Plant phenolics include phenolic s acids, flavonoids, tannins and the less common stilbenes and lignans
(Singleton
et al
., 1999). The recovery of phenolic compounds from plant mate rials is also influenced by the extraction
time and temperature, which reflects the conflicting actions of solubilization and analyte degradation by oxidation
(Block
et al
., 1992). Our results showed that many spices were rich in phenolic constituents and trend to demonstrated
good antioxidant capacity in further evaluations. Moreover, the extensive studies of this class of compounds will
provide clues about their possible pharmaceutical exploration in the field of oncology, diabetes and allergies.
170
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