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.
The antioxidant activity of pomegranate juices extracted by two methods
was determined using three methods: β- carotene, Linoleic acid emulsion, and
DiPhenel Picryl Hydrazyl (DPPH). The juice was extracted by separation arils
from fruits and squee
zed using Cyclone machine (T-1), while the second
extraction method included squeezing the whole halve fruit with previous
machine, (T-2). The potential compounds were determined using ethanol in a
comparison with Butylated hydroxyl Anisole (BHA) as reference antioxidant.
There were significant differences (P<0.05) in the antioxidant activity between
the treatments in all measuring methods. The means of antioxidant activity
amounted to 82.66% in T-1, 86.82% in T-2 and 86.98% in BHA. There was
significant relationship between total phenols and antioxidant activity in all
treatments.
This study was carried out in the laboratories of the Faculty of Agriculture,
Damascus University in 2012 season. Clusters of local yellowish baladi grape
exposed to the concentration (2000 Ppm) of gas SO2 for 3 hours were dried to
moisture conten
t not exceeded 18% by different drying methods (sun drying,
heat drying, solar energy-green house) in the aim of determining their effect on
some chemical indices (total sugar, pH, acidity, solid soluble, non enzymatic
browning), some antioxidants (vitamin C, total phenols) and antioxidant
activity according to 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging
assay. The results showed superiority (p<0.05) of the way solar drying of the
fruits of the grape-treatment with gas SO2 to maintain vitamin C (7.17 mg/ 100
g dry weight) while outperformed the fruits of grapes dried with heat treatment
and gas SO2 in content of phenols (7.24 mg acid Gaelic/ 100 g dry weight).
Results also showed that samples of grapes dried solar and non-treated with gas
SO2 noticeable increase in its activity in the antioxidant, which amounted to
82.42%. The results confirmed that the importance of treatment with gas SO2
prior to the fruits of grapes in reducing (p<0.05) the time required to complete
the drying process, especially in the way of thermal drying to (137 hours)
compared with other transactions.
The main properties(yield of juice, total soluble solid, pH, total acidity, total
sugars), some antioxisant compounds as (vitamin C, carotenoids, total phenol,
anthocyanins), and antioxidant activity measured by DPPH method for some
main Syrian or
ange cultivars (navel, valancia, blood orange, and shamouti)
were investigated. The results showed that valancia was the highest in juice
yield (55.16%), while navel had the highest content of carotenoids(8.68mg/100g)
and the lowest one of vitamin C(31.53mg/100g). Whereas, blood orange was
superior in its content of total phenolic (295.73 mg gallic acid100/g) and
antioxidant activity, (74.833%) among the studied cultivars.
Ten medicinal plants were chosen from various plants in Syria which
used as spices or cooked and Syria traditional medicine. Their names
Rosemary, Damask rose, Chamomile, Sumac, Silver linden, Black
cumin, Thyme, Mint, Laurel and lemon balm.
Mois
ture, yield of extraction, total phenolic content (TPC) and
antioxidant activities of methanol, ethanol, acetone and aqueous extracts
of medicinal plants were investigated.
The TPC were measured by Folin-Ciocalteu method, and the antioxidant
activity was assessed by the scavenging activity towards 2, 2′-diphenyl-
1-picryl hydrazyl (DPPH)-radical.
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.
