Results for the Bacterial Susceptibility Tests.
Results for the Ames Test.
Results
The Folin-Ciocalteu method is commonly used as a
measurement of the total polyphenol content in a sample. The
Folin-Ciocalteu assay depends on an oxidation-reduction reaction in which
Folin-Ciocalteu reagent is added to a sample containing phenols. The
presence of the oxidizable phenol groups in the sample will cause a color
change of the reaction mixture from yellow to blue. The intensity of
the blue color can then be determined using a spectrophotometer at 765 nm
wavelength. Quantitation for this assay was done by analyzing a
calibration curve made from the absorbance of gallic acid at varying
concentrations (absorbance versus mg/L gallic acid). This curve is
used to relate the absorbance of the samples to gallic acid equivalents (GAE)
(Reference 5).
Figure
1: Total polyphenol (TP) content from 5g of the tree bark as equivalent of
Gallic Acid (mg). White Spruce had more TP extracted than all other three
tree bark samples. More TPs were extracted at 100ºC
than
at 50ºC
for all four kinds of tree bark.
From Figure 1, it can be seen that the White
Spruce bark always had the greatest amounts of polyphenols by a large
margin and the Jack Pine bark the least (Trembling Aspen and Paper Birch
were very close). Also, the 100ºC
extracts had a higher level of total polyphenols compared to the 50ºC
extracts from all four kinds of tree bark.
