This study was carried out to determine the total content of flavonoids of dried and
fresh hawthorn flowers and leaves in water and hydroalcolic extracts. The method of cold
and hot maceration was used to prepare these extracts. The active compound
s which were
found in these extracts were detected by many chemical reactions. The results of these tests
showed that the extracts contain: phenols, flavonoids, and saponins.The total content of
flavonoids was determined using spectrophotometric methods by forming complex with
aluminum chloride and measurement absorbance at 510nm, it has been shown that quantity
of flavonoids in dried samples ranges from 0.16 to 1%, while it's quantity in fresh samples
0.026- 0.18%.
In this research, the
antioxidant capacity(DPPH method), and total phenolic content (assayed
by Folin-Ciocalteu method), ,flavonoids, anthocyanins (pH differential
method) and ascorbic acids(2,6-dichlorophenol indophenol) in three fruit
tissues (
peel, pulp and whole fruit), of four apple cultivars commonly in
Syria(Red Delicious, Rome Beauty, Starking Delicious, Golden
Delicious), were studied.
This research studied the impact of planting location and cooking time
periods of (5, 10, 15, 20 and 40 minutes) on the antioxidant effect, and on the
total Phenols and Flavonoids contents using five different samples of Syrian
onions. The results
showed that the total Phenols, total Flavonoids and
antioxidant activity contents were between (279-583)mg/100g dry wt, (80-180)mg/100g dry wt, and (60-75%) respectively. In addition, boiling for
different periods resulted in increased total Phenols from (383 to789)mg/100g
dry wt and in total Flavonoids from (124 to 205)mg/100g dry wt as well as an
increase of (77% to 88%) of antioxidant activity as measured using the DPPH
method.
Total polyphenols (TP), total flavonoids (TF) and (-)-epigallocatechin gallate
((-)-EGCG) were determined in five commercial tea infusions by continuous
infusion method, using the ratio 20g of tea to 1L of water at 85±5 °C and
brewing time between 5-180 min.
