الفهرس 
Moringa seed oilOnly 14 pages are availabe for public view
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Abstract
This study was carried out to evaluate the physical and chemical
properties of moringa, sunflower and soybean oils and effects of their
blends on heat stability of these oils. Six different blends (1-6) of
sunflower and soybean oil with 10, 20 and 40 % moringa oil were
prepared. Addition of olive leave extracts and lycopene extracts to
sunflower oil and soybean oil at different levels (200 ppm, 300 ppm and
400 ppm). The obtained results could be summarizing as follows:
1- Physical and chemical characteristics of moringa, sunflower and
soybean oils:
It could be noticed that the refractive index of moringa oil,
sunflower oil and soybean oil was 1.4571, 1.4742, and 1.4731 (at 25oC),
color was 0.78, 0.00 and 0.00, the acid value was 0.04, 0.07 and 0.29 mg
KOH/ gm oil, the peroxide value was 0.20, 1.39 and 1.57, the iodine
value was 65.55, 136.17 and 136.30, conjugated diene (232 nm.) was
0.17, 0.66 and 0.39, conjugated triene (270 nm.) was 0.07, 0.11 and 0.20,
respectively. Moringa oil had a good Physical and chemical quality
assurance criteria.
2- Physical and chemical characteristics of oil blends
The refractive index of blends (1), (2) , (3) , (4) , (5) and (6) was 1.4729, 1.4721,1.4707, 1.4734, 1.4727 and 1.4713, respectively. The
highest refractive index value was recorded for the blend (4); meanwhile
the lowest value was found in blend (3). The highest color value was
recorded for the blends (3 and 6) which was (0.53) red, meanwhile the
lowest red color value was recorded for blends (1 and 4) which was (0.24(
red). the yellow color value was 35 for all tested oils. The acid value of
blends 1, 2, 3, 4, 5 and 6 was 0.06, 0.05, 0.04, 0.28, 0.27 and 0.24 mg
KOH/g oil, respectively. Peroxide value of blends 1, 2, 3, 4, 5 and 6 was
1.38, 1.35, 1.31, 1.55, 1.50 and 1.47 (m.eqo2/kg oil), respectively. The iodine value of blend 1, 2, 3, 4, 5 and 6 was 125.13, 123.15, 113.69,
128.99, 124.31 and 113.59 respectively. Conjugated diene at (232 nm)
and triene at (270 nm) were 0.62, 0.59, 0.51, 0.69, 0.67 and 0.63 and 0.09,
0.07, 0.04 0.19, 0.18 and 0.15 for blends 1, 2 , 3 , 4, 5 and 6, respectively .
Anisidine value of all the tasted blends were zero value. The totox value
of blends 1, 2 , 3, 4, 5 and 6 was 2.76, 2.70 , 2.62, 3.10, 3.00 and 2.94,
respectively.
3- Fatty acid composition of moringa oil, sunflower oil and soybean
oil:
Moringa oil could be considered as a rich source of oleic acid
76.56 %, while behenic acid was 2.84%. But sunflower oil and soybean
oil are rich of linoleic acid content 54.80% and 60.42%, respectively.
The total saturated fatty acids were 11.35, 11.61, 12.66, 15.31, 15.16 and
15.05 %, while the total unsaturated fatty acids contents were found to be
88.65, 88.39, 87.34, 84.69, 83.712 and 82.95% for tested blend 1, 2, 3, 4,
5 and 6, respectively.
4- Fatty acids composition of moringa , sunflower oils and their blends.
The fatty acids composition of blends from 1 to 3 was carried out.
The total saturated fatty acids were 11.35, 11.61 and 12.66 %,
respectively while the total unsaturated fatty acid contents were found to
be 88.65, 88.39 and 87.34 % for tested blends 1, 2 and 3, respectively.
Palmitic acid (C16:0) was found to be the dominant saturated fatty acid and
accounted 6.33, 6.45 and 6.99 % in all the former tested blends,
respectively. The major unsaturated fatty acid was linoleic acid (49.66%)
for blend (1) and (47.88%) for blend (2). Meanwhile, oleic acid proved
the dominant acid for blend (3) being 47.21%. It could be noticed that
oleic acid level was increased with increasing the rate of moringa oil in
blends. 5- Fatty acids composition of moringa, Soybean oils and their blends.
The gas chromatographic analysis for fatty acids composition of
blends (4 to 6) was analysed.
The total saturated fatty acids were 15.31, 15.16 and 15.05 %,
while the total unsaturated fatty acids contents were found to be 84.69,
83.71 and 82.95 for the tested blends 4, 5 and 6, respectively. Palmitic
acid (C16:0) was found to be the dominant saturated fatty acid and
accounted 9.74, 9.43 and 8.22 % in all the former tested oils; respectively.
The major unsaturated fatty acid in blend 4, 5 and 6 was linoleic
acid for blend 4 (49.5%) and (43.12%) for blends (5), meanwhile, it was
oleic acid (42.20%) for blend (6).
On the other hand, it could be noticed from the obtained results a
gradual increases in the oleic acid content of tested soybean blends as a
function of increase in the proportion of moringa seed oil (MOO). The
increasing rate of MOO in blending process could result in modification
of fatty acid profiles of the blends and thus improve the oxidative stability
during storage and thermal processing.6-Oxidative stability:
Induction period of sunflower and soybean oils increased from
7.77 and 7.00 to 11.40, 15.28& 22.40 and 9.22, 13.72 and 17.20 for
different ratio with treated of moringa oil. Also adding olive leave extract
increased sunflower oil and soybean oil stability from 7.77 and 7.00 hours
to 11.87, 13.92 and 17.05 at level of addition 200, 300 and 400 ppm in
sunflower oil and 10.64, 12.26 and 14.43 at level of 200, 300 and 400
ppm for soybean oil, respectively. from the same results it could be
observed that addition of 200 ppm TBHQ to sunflower oil and soybean
oil caused a pronounced increase in its stability to 12.70 and 11.37 hours
respectively. Adding lycopene increased sunflower oil and soybean oil
stability from 7.77 and 7.00 hours to 13.69, 9.80 & 9.56 and 12.24, 8.8 &
8.51.Moringa oils exhibited a higher good oxidative stability (50.4 hours) ,
and the longer induction period for blends (3) (22.40 hours), blend (6)
(17.20 hours), SUN treated with 400 ppm KOL (17.05 hours), SBO
treated 400 ppm KOL (14.43 hours), SUN treated with 200 ppm
lycopene (13.69 hours) and SBO treated 200 ppm lycopene (12.24 hours),
these tested oils used frying process 180 º C for 30 hours
7- Radical scavenging activity (DPPH) of the oils
The highest activity of moringa oil being ( 76.87%) followed by
blend (3) 43.64%, blend (6) 35.45%, sunflower oil treated with 400 ppm
KOL extract 36.54%, 400 ppm soybean oil treated with KOL extract
31.54%, 200 ppm sunflower oil treated with lycopene 29.09% and 200
ppm soybean oil treated with lycopene 25.86%. 8- Tocopherols content (mg/ 100 oil) of the tested oils
The highest levels of total tocopherols were found in moringa oil
(20.61 mg/100 g) and the lowest value in SBO : lycopene 200 (11.29
mg/100 g). Moringa oil contained a much higher contents of total
tocopherols than all tested oils which has a greater antioxidant activity,
thus it would be expected to be an excellent oxidative stability and
protection of moringa oil during frying process.
9- Total Phenolic (mg/ 100 oil) of the tested oils
The total polyphenol content of moringa, sunflower and soybean
oils were (49.61, 22.30 and 14.09 mg/100g respectively). While the
highest total polyphenols content of blends was recorded for blend SUN:
MO 60:40 (39.89 mg/ 100g) and the lowest content was lower for blend
SBO: MO 90 :10 (15.29 mg/ 100g). from the obtained results it could be
noticed that the effect of KOL extract at concentration (200- 300 - 400
ppm) on sunflower and soybean oils. the highest content of polyphenol
was found in sunflower oil treated with 400 ppm KOL extract ( 26.48 mg/ 100g) and the lowest value of this levels was found in SBO :
lycopene 200 ppm (14.29 mg/ 100g)
10- Effect of frying on the physical and chemical characteristics of the
investigated blends.
1- The highest oxidative stability blends (3 and 6) and treated oils
sunflower and soybean oils with KOL (400 ppm) and lycopene
(200 ppm) were used in frying. The physical properties of these
samples were determined during frying process. The refractive
index of blends slightly changed, meanwhile increased gradually
during frying process for the treated oils and the color
measurement of all tested frying oils increase in red units. Blends
3 and 6 characteristics with a good physical properties.
2- The chemical characteristics of the oxidative stability blends were
increased during frying process and the blend 3 and 6 were lower
than sunflower treated with 400 ppm KOL, soybean treated 400
ppm KOL, SUN treated with 200 ppm lycopene and SBO treated
200 ppm lycopene 3- Acid value of blend 3 and 6 was increased from 0.04 to 0.92 and
from 0.24 to 1.84 mg KOH/g oil after 30 hours of frying
respectively. While it was 1.95, 1.67, 2.55 and 2.11 (mg KOH/g
oil) after 30 hours of frying for sunflower oil, sunflower oil treated
with 200 ppm TBHQ, soybean oil and soybean oil treated with
200 ppm TBHQ respectively. The changes in acid value after 30
hours of frying was found to be 1.95, 1.67, 1.70, 1.88, 2.55, 2.11,
2.21 and 2.45 for sunflower oil, sunflower oil treated 200 ppm
TBHQ, sunflower oil treated 400 ppm KOL extract, sunflower oil
treated 200 ppm lycopene, soybean oil, soybean oil treated 200
ppm TBHQ, soybean oil treated 400 ppm KOL extract and
soybean oil treated 200 ppm lycopene ,respectively.4- Peroxide value of blends 3 and 6, after frying 30 hours was
increased from 1.31 to 14.85 and from 1.47 to 16.34 meq.o2 / Kg
oil, respectively. Soybean oil after 30 h of frying had the highest
value of peroxide value (27.43 meq.o2 / Kg oil), than the soybean
with 200 ppm TBHQ (20.66), while sunflower oil (23.21 meq.o2 /
Kg oil) and sunflower oil with 200 ppm TBHQ being 16.38
meq.o2 / Kg oil. The changes in peroxide value after 30 hours of
frying 23.21, 16.38, 18.83, 21.15, 27.43, 20.66, 22.10 and 24.14
for sunflower oil, sunflower oil treated 200 ppm TBHQ, sunflower
oil treated 400 ppm KOL extract, sunflower oil treated with 200
ppm lycopene ,soybean oil, soybean oil treated 200 ppm TBHQ,
soybean oil treated 400 ppm KOL extract and soybean oil treated
with 200 ppm lycopene respectively.5- Anisidine value confirmed that frying medium blend (3) was
found to be more resist to oxidation at high frying temperature
than the other frying oils. This observation could be due to the
presence of a high concentration of monounsaturated fatty acids
(47.21%) and lower linoleic acid 38.52%, compared to the other
frying oils. At the end of the frying process, the p-AV were found
to be (23.51, 22.78, 19.61, 17.84,10.34, 25.67, 24.11, 22.41, 20.00
and 15.96) for sunflower oil, sunflower oil treated with 200 ppm
lycopene , sunflower oil treated with 400 ppm KOL extract ,
sunflower oil treated TBHQ, blend (3), soybean oil , soybean oil
treated with 200 ppm lycopene, soybean oil adding 400 ppm KOL
soybean treated with TBHQ and blend (6) respectively .
6- TOTOX value of the frying oils were found to be 69.93, 65.08,
57.27 50.60, 40.04, 80.53, 72.39, 66.61, 61.32 and 48.64 for
sunflower oil, sunflower oil treated 200 ppm lycopene, sunflower
oil treated with 400 ppm KOL extract, sunflower oil treated with
TBHQ, blend (3), soybean oil, soybean oil treated 200 ppm lycopene, soybean oil treated with 400 ppm KOL extract, soybean
oil treated with TBHQ and blend (6) respectively.
7- Conjugated Diene (232 nm) of blend 3 and blend 6 after frying
was increased to 1.27 and 2.12 after 30 hours of frying,
respectively. Meanwhile, triene (270 nm) was increased 0.50 and
1.00 after 30 hours of frying, respectively. The changes in UV
absorption at 232 and 270 nm after 30 hours of frying 1.86, 1.46,
1.61, 1.73, 3.10, 2.49, 2.65, 2.92 and 1.07, 0.76, 0.81, 0.98, 1.46,
1.21, 1.27 and 1.39 for sunflower oil, sunflower oil treated 200
ppm TBHQ, sunflower oil adding 400 ppm KOL extract,
sunflower oil treated with 200 ppm lycopene , soybean oil,
soybean oil treated 200 ppm TBHQ, soybean oil treated 400 ppm
KOL extract and soybean oil treated with 200 ppm lycopene
extract, respectively.
8- Total polar content of blend 3 was 20.99% after 30 h of frying.
This value is lower than the discarding limit. While polar content
of blend 6 was 23.77% after frying for 24 h. The TBHQ had the
strongest effect in retarding formation of total polar components
during frying followed by 400 ppm KOL extract and 200 ppm lycopene extract. The total polar components increased gradually
during frying in all oils.
9- Polymer content in sunflower oil, sunflower oil treated with 200
ppm TBHQ, soybean oil, soybean oil treated with 200 ppm
TBHQ, blend 3 and blend 6 was 2.72, 2.27, 3.38, 2.88, 1.92 and
2.44 after 30 hours of frying, respectively. Polymer content of all
oils increased slowly during the first time of frying, followed by a
marked increases over the second 3 days of frying. It was noticed
that the rate of polymer formation was faster in the oils without
antioxidants than in the oils with TBHQ and extracted KOL,
lycopene extract.10- Oxidized fatty acids increased gradually with increasing frying
time in all samples; however, more oxidized fatty acids were
formed in soybean oil than in all samples. Blends 3, 6 , sunflower
oil and soybean oil with KOL extracted, lycopene and TBHQ
resist to some extent formation of oxidized fatty acids and hence
are more stable during frying.
Fatty acids composition after 30 hours for frying process showed a
decrease in the unsaturated fatty acids (16:1, 18:1, 18:2, 18:3 and 20:1) ,
resulting increase in the saturated fatty acids (16:0, 18:0, 20,0 and 22:0)
content, at different rates affecting by the nature of fatty acid (chemical
structure and configuration). The oleic acid (18:1) which is less prone to
the oxidation than polyunsaturated fatty acid (18:2 and 18:3) which
demonstrated a higher decrease during frying period up to 30 hours.