Transcript (Tamers) and Date Syrup (Dibs)

•The free phenolics, total phenolics and total flavonoids (g GAE/100g) are higher in dibs than in tamer. This can indicate that partitioning of the phenolic compounds had occurred from tamer to dibs. Such higher content of phenolics may be responsible for the higher antioxidant and antiradical activity in dibs than that in tamer.
Partitioning of Antioxidant /Antiradical Activities and Antioxidant Compounds Between Dried Dates (Tamers) and Date
Syrup (Dibs)
Fatima Jaffer Ahmed, supervised by Dr. Ameer Al-Laith
Biology Department, Science college , University of Bahrain
Materials and Methods
Introduction
Reactive oxygen species (ROS) and free radicals are substance that can cause severe
damage to the tissues and organisms when produced internally. However, in our body,
there are specific substances that can prevent their formation or protect against their
harmful effect by delaying, preventing oxidation or radical formation at relatively low
concentration. These substrates are called antioxidants and antiradicals.
Date palm fruits are a rich source of phenolic compounds which possess antioxidant and
antiradical activities. The concentration of these compounds varies with cultivar and
maturity stages.
Samples
Tamer of four cultivars (Khalas,
Khunaizi, Ruzaiz and Selawi)
from Bahrain and Saudi Arabia
and three Bahraini date-dibs.
Results
Discussion
a, Data are expressed as mean ± SD (n=3). The mean ± SD followed by the same letter, within a column, are not
significantly different (p>0.05), b, not determined
1.600
Khalas
tamer
Khalas Fresh Khunaizi Khunaizi
dibs Khunaizi tamer
dibs
Fresh dates, tamer and dibs of Khalas and Khunaizi
Figure 1: The figure shows the antioxidant
activities (FRAP values) of fresh dates, tamers and
dibs of two cultivars (Khalas and Khunaizi).
1.600
1.400
Total flavonoids (g/100g)
FRAP value (mmole/100g)
Total phenolics (g/100g)
a, Data are expressed as mean ± SD (n=3). The mean ± SD followed by the same letter, within a column, are not
significantly different (p>0.05), b, the standard at 5 mg.
Fresh
Khalas
1.200
1.000
0.800
0.600
0.400
0.200
0.000
Fresh
Khalas
The antioxidant/antiradical activities were
estimated by four different assays:
• The Ferric Reducing Antioxidant Power (FRAP)
assay.
• The Diphenylpicrylhydrazyl (DPPH) Radical
Scavenging assay.
• Nitric Oxide (NO) Scavenging assay.
• Deoxyribose Degradation assay (Hydroxyl (OH)
Scavenging assay)
The antioxidant/antiradical constituents includes:
• Total Anthocyanins
• Total Carotenoids
• Total Phenolics (free and esterified)
• Total Flavonoids.
Table 2: Antioxidant components of fresh, tamer, and dibs of the
cultivars Khalas and Khunaizia.
Table 1: FRAP value, DPPH inhibition, OH inhibition, and NO inhibition of fresh, tamer and dibs
of the cultivars Khalas and Khunaizia.
2.000
1.800
1.600
1.400
1.200
1.000
0.800
0.600
0.400
0.200
0.000
Methods
Khalas
tamer
Khalas Fresh Khunaizi Khunaizi
dibs Khunaizi tamer
dibs
Fresh dates, tamer and dibs of Khalas and Khunaizi
Figure 2: The figure shows that the total phenolics of
fresh dates is higher than that of tamers, but of tamers is
lower than that of dibs.
1.400
1.200
1.000
0.800
0.600
0.400
0.200
0.000
Fresh
Khalas
Khalas
tamer
Khalas Fresh Khunaizi Khunaizi
dibs Khunaizi tamer
dibs
Fresh dates, tamer and dibs of Khalas and Khunaizi
Figure 3: the total flavonoids of fresh dates is
higher than that of tamers, but of tamers is lower
than that of dibs.
The overall FRAP value (mmole/100g) of tamers is
lower than that in dibs (Table 2). It can be inferred
that the increase in FRAP value of dibs was due to
the soluble components that leaked from tamer to
dibs and has antioxidant activities such as
phenolic compounds
The amount of Khalas and Khunaizi dibs were
needed to scavenge the 50% of NO., DPPH. and
.OH radical is lower than that of tamer of the same
cultivars, indicating that dibs exhibited higher
antiradical activity than tamer.
The anthocyanins and carotenoids contents
(mg/100g) were lower in dibs than in the tamer,
which may be attributed to several environmental
factors including heat, light, temperature and
storage.
The free phenolics, total phenolics and total
flavonoids (g GAE/100g) were higher in dibs than
in tamer. This indicates that partitioning of the
phenolic compounds had occurred from tamer to
dibs. Such higher content of phenolics may be
responsible for the higher antioxidant and
antiradical activity in dibs than in tamer.
Conclusion
• Antioxidant and antiradical activities
were higher in dibs than in tamer
• The higher antioxidant/antiradical
activities of dibs resulted from the
partitioning of compounds that normally
contribute to the antioxidant/ antiradical
abilities between tamer and dibs, since
most phenolics are water soluble and
can leak out from tamer to dibs.
• The major contributors to
antioxidant/antiradical activities were
the phenolic compounds
References
1Al-Farsi et al. (2005) J. Agri. F. Chem. 53:7586–7591.
2Biglari et al. (2008) F. Chem. 107(4): 1636-1641.
3Halliwell et al. (1991) Amer. J.Med. 91(3C): 14S-22S.
4Halvorsen et al (2002) J. Nutr. 132: 461-471.
5Mansouri et al. (2005) F. Chem. 89(3): 411-420.
6Vinson et al. (2005) J.Amer.Col. Nutr. 24(1):44–50.