Some local natural sources of antioxidant such as orange peel extract (Citrus
sinensis), pomegranate peel extract (Punica granatum) and ginger extract
(Zingiber officinale L.) were evaluated during 5 days storage of refined palm oil
at 63°C as com
pared to the synthetic antioxidant such as propyl gallate. The
above extracts were obtained with ethanol and oil (palm oil). Those extracts
were added to the oil at two different levels (100 ppm and 200 ppm).
Antioxidant activity of natural extracts, synthetic antioxidant and the control
treatment without antioxidant under thermal treatment (Schaal test) was
assessed by measuring acid value (AV), peroxide value (PV), iodine value (IV)
and refractive index (RI) during 6 days storage of refined palm oil at
temperature mentioned above. Antioxidant activity also measured by studying
the stability of oil by the use of rancimat method. All treatments exhibited
antioxidant activity. Statistical analysis results were shown that the
pomegranate peel extract treatment was significantly (P<0.05) superior than
the orange peel extract and ginger extract treatments whereas, it was not
significant difference about propyl gallate treatment.
Orange is used in the juice industry, yielding important quantities of by products.
Orange peel is analyzed for chemical composition and water holding capacity. Data show
that, it has high amount of crude fiber, phenolic contents and antioxidant ca
pacity, also it
has high level of water holding capacity. Biscuits are prepared from blendes which contain
a different proportion (5, 10, 15, 20 and 25)% of orange peel flour are also evaluate for
physical and sensory characteristics, chemical composition and rheological properties for
this blendes.
The sensory evaluation does not show any significant difference between control and
that adds with 10% of orange peel flour. Physical parameters, namely, diameter, thickness
and spread ratio were tested. The diameter and thickness of orange peel substituted biscuits
were decreased, whereas spread ratio of biscuits increase with increasing levels of it.
The data reveals that incorporation of orange peel powder in biscuits increase crude
fiber, ash, phenolic contents and antioxidant capacity, it decreases the carbohydrate
content. Rheological properties of the blended flour show increase in water absorption and
stability.
Addition of 40ppm xylanase enzyme reduce the hardness value of the sample in
general, it also decrease the spread ratio as compared to control samples with no enzyme
added.
Sensory evaluation results show good overall acceptability scores for the biscuits
contain 10% orange peel with and without xylanase.
The study investigated the possibility of removing heavy metal ions (Cd, Pb) from
aqueous solutions using adsorption method on the citrus peel (orange), which is a solid
waste available in abundance especially in the Syrian coast as well as easy to
use at low
cost. The optimal conditions for the simultaneous adsorption of the ions (Cd 2+, Pb 2+) on
the surface of orange peel (dry, soft) were determined.The concetration of ions was
determined using (DPASV) method Which is characterized by Sensitivity and high
accurawcy. The results showed that the optimum adsorption conditions were at pH = 5 ,
equleibrium time = 60 min, and the initial concentration is ( C0 = 50-200) ppm,The
application of the Langmuir and Frienlish models showed that Frienlish model is best fited
for expressing the adsorption of Pb ions on the surface of dry and soft orange peel and for
expressing the adsorption of Cd ions on the surface of soft orange peel , Langmuir model
is best fited for expressing the adsorption of Cd ions on the surface of dry orange peel.
The method applied its selected terms to realistic samples of processed and industrial
waste water, which showed a unique response as a purification method for the water
media.
