Proceedings Book / Bildiri Kitabı - Orman Fakültesi - Süleyman ...

2 nd International Non-Wood Products Symposium 8-10 September 2011 - Isparta/TURKEY
2.7.Determination of free radical scavenging
activity
The free radical scavenging activity of extracts
were examined by 1, 1-diphenyl-2- picrylhydrazyl
(DPPH) using the method of Dorman et al. (2003).
A 50 μL aliquot of olive oil phenolic extract, in
Tris-HCl buffer (50 mM, pH 7.4), was mixed with
450 μL of Tris-HCl buffer (50 mM) and 1.0 mL of
DPPH• (0.1 mM, in methanol). After 30 minutes
incubation in darkness and at ambient temperature,
the resultant absorbance was recorded at 517 nm.
The percentage inhibition was calculated using the
following equation;
Inhibition (%) = [(Absorbance of control-
Absorbance of sample)/Absorbance of control] x
100
Extract concentration providing 50% inhibition
(IC 50 ) was calculated from the plot of inhibition
percentage against extract concentration. All
determinations were done in triplicate.
3.RESULTS AND DISCUSSION
The yield of seed oil of B. orphanidis growing
wild in Mediterranean region of Turkey gwas
found as 20.10 % by soxhlet extraction method.
As shown in Table1, 5 components were identified
in this oil, which represented about 99.88 % of the
total composition of the oil. The major
constituents of of the oils were determined as
linoleic acid (56.25%), oleic acids (n:9, 26.89%
and n:7, 0.98%), palmitic acid (12.62%) and
stearic acid (2.34%), (5.82), respectively. There is
no report on the seed oil yield and constituents
obtained from calyx of B. Orphanidis. As our
results, grape seeds have also 10 to 20% oil
(Schuster, 1992) and the oil is especially rich in
unsaturated fatty acids (Göktürk Baydar and
Akkurt, 2001).
In Table 1, the most abundant fatty acids was
found as linolenic acid (poly-unsaturated). There
was no linolenic acid in seed oil of B. Orphanidis.
Poly-unsaturated fatty acids such as linoleic and
linolenic are essential for the human body because
they cannot be synthesized in the body. From this
point of view, grape seed and pomace oil very rich
in linoleic acid may be a valuable source of dietary
fat. In addition poly-unsaturated fatty acids are
also very important for the stability of oils because
of the chemical reactions in the double bonds. The
rates of those oxidation reactions depend on the
number of double bonds in the carbon chain (Hall,
Flower and Roberts, 1981; Mayes, 1983). So, seed
oil of B. Orphanidis having no linolenic acid can
be advantages in terms of human consumption and
the shelf-life of the oil. The second abundant fatty
acid in the seed oil was oleic acid. Oleic acid, a
monounsaturated fatty acid, has also great
importance in terms of their nutritional implication
and effect on oxidative stability of oils (Aparicio
et al., 1999).
In Table 2, the tocopherol contents of seed oil
from Biebersteinia orphanidis was given.
Tocopherols are one of the most powerful natural
fat-soluble antioxidants. Tocopherols can act as
antioxidants by two primary mechanisms, a chainbreaking
electron donor mechanism (Kamal-Eldin
and Appelqvist, 1996). In the other hand, α-
tocopherol shows the highest vitamin E activity,
thus making it the most important for human
health and the biological activity (Guthrie and
Kurowska, 2001). In our oil of seed samples, α-
tocopherol was the most abundant tocopherol and
found as 954.10 ppm in the oil. β, and -
tocopherols were also 17.75, 6.80 and 0.60 ppm in
the oil, respectively. Although, γ and δ-
tocopherols followed the α-tocopherol with the
lower values and -tocopherol (ppm) was detected
higher them. α-tocopherol was the most abundant
tocopherol in the oil extracts, as it was reported
before by Gliszczynska-Swiglo and Sikorska
(2004).
Table-1. Yield and fattt acid composition of seed oil from Biebersteinia orphanidis
Oil yield
(%)
Palmitic acid
(C16:0)
Fatty acid composition (%)
Stearic acid Oleic acid Oleic acid
(C18:0) (C18:1, n:9) (C18:1, n:7)
Linoleic acid
(C18:3)
20.10±0.42 a 12.62±0.20 2.34±0.00 26.89±1.02 0.08±0.00 56.25±2.40
a Values expressed are mean S.D. of three experiments.
Table-2. Tocopherol composition of seed oil from Biebersteinia orphanidis
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