Phenols were studied in the leaves of Syrian olive varieties collected from (Harasta
and Ghouta, Damascus Countryside and Qalamun). Phenolic compounds were extracted
from the olive leaf varieties after disposal of plant pigments and fatty compounds, and
total phenols separated with solvent (methanol - water).
The optimal conditions for the extraction of polyphenolic compounds from hard
Syrian wheatvarieties (Hourani, Doma1,Bohoos11) were determined using response
surface methodology. A Central Composite Design was used to investigate the effects of
thr
ee independent variables, namely solvent concentration, extraction temperature and
time on the response phenolic content. The independent variables were at three levels and
their actual values selected on the basis of preliminary experimental results. A secondorder
polynomial model was used for predicting the response.
Regression analysis showed that more than 95-97% of the variation was explained by
the models. The optimal conditions for phenolic compounds extraction were found to be
acetone concentration of 49.5 %v/v, extraction temperature of 55.5°C, extraction time of
42.5min, for wheat. Under the optimum conditions the corresponding predicted response
values for polyphenolic compounds were 0.976 mg EGA forHourani, 0.947 mg EGA
forDoma1 and 1.316 mg EGA for Bohoos11. The phenlics were extracted under optimum
conditions to check the validity of model, and the experimental values were 0.969±0.05
,0.932±0.03 and 1.214±0.06 mggalic acid equivalent /g dry weight from wheatvarieties
(Hourani, Doma1,Bohoos11) respectively. The good agreement between predicted and
,experimental values indicated suitability of the model employed and the success of
response surface methodology in optimizing the extraction conditions.
Phenolic compounds are known to be present in high concentration
in various of agro industrial wastes such as olive mill wastewater. As
they are highly biorecalcitrant a possible treatment by Advanced
Oxidation Processes has to be investigated.
T
he photocatalytic degradation of the phenolic acids p-Hydroxybenzoic
acid, Dihydroxybenzoic acid, gallic acid, vanillic acid, syringic acid) in the
presence of TiO2 deposit on a glass plate has been reported. A comparison for
the adsorption properties and the kinetics of reaction have been studied. The
kinetics were found to be first order for all compounds and were compared
with the compounds’ structures. The reaction rate for the compounds was
found as the order Di-HBA < GA < p-HBA ≈ SA ≈ VA.
The influence on the photdegradation rate of various parameters as pH, and
substrate’s concentration was studied for p-Hydroxybenzoic acid only. It was
found that the reaction is pH and substrate’s concentration dependence.
A removal efficiency (50-70%) was determined after 5hr using UVlamp
(15W- λ=360nm) and it increased up to 95% when H2O2 was
added.
This study aimed at investigating the effect of some environmental factors on the phenolic
contents of the Rhus cotinus L. plant. Plant samples (leaves, flowers and bark) were
collected from three aspects (south, west and north) at four altitudes (
0-300, 300-600, 600-
900, ˃900m) in the countryside of Jableh in 2016. The fresh samples were extracted using
95% ethanol as an extraction solution, then the total contents of the phenolic compounds
were determined spectrophotometrically using the Folin-Ciocalteu reagent, expressing the
result by (mg gallic acid/1g fw) using a Spectrophotometer.
