Content uploaded by Olonisakin Adebisi
Author content
All content in this area was uploaded by Olonisakin Adebisi on Jan 20, 2016
Content may be subject to copyright.
Ife Journal of Science vol. 16, no. 2 (2014)
COMPARATIVE STUDY OF ESSENTIAL OIL COMPOSITION OF FRESH AND DRY
PEEL AND SEED OF CITRUS SINENSIS (L) OSBECK VAR SHAMUTI AND CITRUS
PARADISI MACFADYEN VAR MARSH
Olonisakin Adebisi
Department of Chemical Sciences
Adekunle Ajasin University, PMB 001. Akungba-Akoko. Ondo-State. Nigeria.
E-mail: adeoloni@yahoo.com
(Received: 2nd June, 2014; Accepted:17th July, 2014 )
Citrus essential oils have an impressive range of food and medicinal uses. In this study investigation has been
conducted on the variation in the yield, chemical composition and their identities in oils isolated from fresh and
air-dried peel and seed of orange (Citrus sinensis) and grape(Citrus paradisi) planted in a cocoa farm. The yield of
solvent-extracted essential oils from the fresh peel and seed ranged between 0.31 and 1.01%, while the yield in
the air-dried peel and seed of the two different citrus samples ranged between 0.98 and 2.30%. The four major
compounds present in all the oils are limonene, myrcene, alpha terpinene and camphene which ranged between
74.97 - 90.58%, 5.19 - 10.41%, 0.14 - 4.00% and 0.05 - 3.87%, respectively in fresh peel and seed. In the air-dried
peel and seed their values ranged between 58.64 - 77.30%, 0.08 - 5.04%, 0.05 - 3.68% and 0.02-4.88%,
respectively for the four compounds. The fresh peel and seed have lower yield but contain higher percentage
concentrations of major compounds that serve as compound identification for the citrus family. Air-dried peel
and seed have alcohol components like spathulenol (9.78 - 15.13%), linalool (5.05 - 9.27%), nerol (7.98 - 8.60),
alpha terpeniol (1.06 - 1.15%) and farnesol (1.54 - 1.66%) which were not present in fresh samples of the two
different citrus samples. Apart from concentration differences, the results of this study are similar to other
research work in other regions of the world on citrus; the only difference was the identification of camphene in
this study but which was not found in citrus located in other regions of the world under consideration.
Keywords: Citrus peel, Seed, Fresh, Air-dried, Essential Oil.
ABSTRACT
211
INTRODUCTION
Citrus essential oils are obtained from various
Citrus species found within the family Rutaceae
and the subfamily Aurantioideae; these include
about 17 species distributed throughout the
tropical and temperate regions (Davies and
Albrigo, 1994; Shaw, 1977). They are evergreen
trees that give fruits of different forms and sizes
(from round to oblong), which are full of
fragrances, flavor and juice. The citrus genus
includes various species; oranges (Citrus sinensis),
limes (Citrus aurantifolia), tangerine (Citrus
reticulate), lemons (Citrus limon) and grapefruit
(Citrus paradisi) (Burcu et al., 2011; Mohammed et
al., 2010). Citrus is one of the most important
commercially-grown crops in the world. The
world production of citrus was estimated to be
51.8 million metric tonnes during 2013 with Brazil,
China and United States as the first three leading
producers in the world and Egypt, South Africa
and Morocco, respectively as the leading
producers in the African continent (USDA, 2014).
Citrus essential oil are a mixture of volatile
compounds and mainly consists of monoterpene
hydrocarbons of about 70-95% along with smaller
amount of sesquiterpene hydrocarbons which are
responsible for a characteristic flavor
(Muhammad, 2006).
Although, the fruits are mainly used for dessert, it
has significant economic value for its essential oil
(EO) due to their aromatic compounds (Minh et
al., 2002). Citrus flavours are used in beverage,
confectionary, cookies and desserts (Buchel, 1989;
Dharmawan et al., 2007). The exocarps of C.
reticulata and C. sinensis are used for flavorings of
liquor. The composition of the oil is significantly
affected by the ripeness of fruits, vegetative stage
of plant, storage condition and extraction method
(Njoroge et al., 2006; Venkateshwarlu and Selvaraj,
2000). The quality and the odour of the oil are
influenced by the limonene content which may
vary in the different agro-climatic conditions
(Dharmawan et al., 2007).
Like many other plant families, Rutaceae has been
reported to be a source of potent botanical
insecticide. Peel and seed solvent extract of citrus
plant have shown insecticidal activity against
several coleopteran and dipteran species (Su et al.,
212
1972; Greany et al., 1983; Sheppard 1984; Salvatore
et al., 2004). Previously it has been established that
C. aurantium peels contain secondary metabolites
with insecticidal activity against B. oleae adult
(Siskos et al., 2007).
Citrus essential oils have been applied in many
products, such as foods, beverages, cosmetics and
medicines, as flavouring agents as well as for
aromatherapy. They are also used for their
germicidal, antioxidant and anticarcinogenic
properties (Guenther, 1948; Mukhopadhyay,
2000). The active constituents exist in citrus EOs,
such as limonene, a-pinene, b-pinene and a-
terpinolene which exhibit a wide spectrum of
antimicrobial activity, as reported by many studies
in other plants (Jirovetz et al., 2005; Magwa et al.,
2006; Skocibusic et al., 2006; Matasyoh et al., 2007).
The biological properties of EOs extracted from
medicinal plants may show differences depending
upon the distinctness in cultivation, origin,
vegetative stage and growing seasons of the plants
and geographical location (Deans et al., 1992;
Muller-Riebau et al., 1995; Kustrak et al., 1996;
Leung and Foster, 1996; Milos et al., 2000; Jerkovic
et al., 2001). In addition, other factors that can
affect chemical composition are extraction
process, stage of harvesting and post-harvest
processing (Dean et al., 1992).
In this study, the main aim was to obtain essential
oils from orange (C. sinensis) and grapefruit (Citrus
paradisi L.) peel and seed using solvent extraction
method under fresh and air dried conditions in
order to compare the yield and chemical
composition. Also this study will obtain
information about the chemical variability of the
peel and seed from this region of Nigeria and
compare to result from other regions.
MATERIALS AND METHODS
Sample Collection and Preparation
The fresh fully matured ripened fruits of two
species of Citrus: Sweet orange (C. sinensis) (CS)
and grape (C. paradisi) (CP) were collected from a
cocoa farm in Isinbode-Ekiti, Ekiti-State. Nigeria.
The citrus varieties were identified in the
Department of Plant Science and Biotechnology
of Adekunle Ajasin University, Akungba Akoko.
Ondo State, Nigeria. The two citrus fruit species
were washed free of sand over tap water. The
fruits were then peeled off carefully with the help
of a sharp razor blade to avoid any damage of oil
glands. Due to practical reasons, the Citrus peels
under testing were processed under two
categories: one portion used as fresh, the other air-
0
dried at ambient temperature (30 C) were ground
and extraction took place immediately while the
other portion was air-dried.
Extraction
Precisely, 200 g of each of the samples was packed
into a Soxhlet apparatus and extracted
exhaustively with 750 ml of Hexane for 3 h. The
solvent was recovered using a rotary evaporator.
The oils were made to be moisture free by filtering
through the anhydrous sodium sulphate. The oils
were transferred into brown sample bottles and
stored in the refrigerator until ready for analysis
Analysis of the Components
The volatile constituents were identified by gas
chromatography technique using direct injection
in the split mode with a split ratio of 20:1 under the
following conditions: Hewlet-Packard 6890
equipped with a quartz capillary column; 30 mm x
0.25 mm internal diameter and 0.25 µm film
thickness was used. Hydrogen was the carrier gas
o
at 1.0 ml/min flow rate; oven temperature, 40 C to
o o
200 C at a rate of 5 C/min then held isothermal
for 2 min. Injector temperature and volume are
o
150 C and 1.0 µl, respectively. The ionization of
the sample components was performed on E.I
mode (70eV). The identification of different
constituents was performed by comparison of
their retention time and mass spectra with those
of the library.
RESULTS AND DISCUSSION
The yield and colour of the essential oil from the
peel and seed samples are presented in Table 1.
The yield ranged between 0.31-1.01% in fresh peel
and seed with peel having the lowest values. The
air-dried peel and seed had the yield ranged
between 0.98 - 2.30%. The fresh samples generally
had low yield when compared to dry samples, this
may be due to the high water content of the
materials. The seed of both citrus had higher yield
when in dry condition than in fresh. According to
Williams, 1996, depending on the variety of the
fruit peel or seed, citrus yields essential oil content
Olonisakin Comparative Study of Essential Oil Composition of Fresh and Dry Peel and Seed of Citrus Sinensis:
213
of between 0.5 and 5.0%.
Table 1: Essential Oil Yield and Colour of Essential Oil from Peel and Seed of CS and CP
Species
Condition
Yield %v/w Colour
C. sinensis (peel)
Fresh
0.40 Light green
C. sinensis (seed)
Fresh
0.67 Light yellow
C.paradisi (peel)
Fresh
0.31 Light green
C.paradisi (seed)
Fresh
1.01 Light yellow
C. sinensis (peel)
Dry
1.09 Dark green
C. sinensis
(seed)
Dry
1.73 Dark yellow
C.paradisi (peel)
Dry
0.98 Dark green
C.paradisi (seed)
Dry
2.30 Dark yellow
The yield obtained from this study with respect to
the effects of drying condition on peel and seed
essential oil are in agreement with the findings of
Asekun et al. (2007) who also investigated higher
oil contents from oven-dried samples of
Helichrysum odoratissimum in comparison with fresh
material. Asekun et al. (2006) had earlier studied
the effects of drying on the yield and chemical
composition of essential oil from the aerial parts
of Leonotis leonurus and found that the oils derived
from sun-dried plant material had better yield than
those from the air and oven-dried materials. Some
other reports in the literature also revealed
considerable effects of drying on the yield and
characteristics of the essential oils (Rahula et al.,
1973; Laranja et al., 2003). Furthermore, the yield
obtained in this work which ranged between 0.31 -
2.30% is slightly higher than the one obtained by
Tu et al. (2002) (0.20 -2.0%) and Kamal et al. (2001)
(0.24 – 1.07%). This may be due to the method of
extraction in their studies, steam distillation was
used and solvent extraction was used in this study.
In essential oil extraction methods, solvent
extraction technique has been found to have
higher yield than other methods.
The results of the essential oil composition of the
fresh and air-dried peel and seed of C. sinensis and
C. paradisi are shown in Table 2. Peel and seed oils
consisted almost exclusively of hydrocarbons,
with limonene as major component. Limonene,
myrcene, a-pinene and camphene were the main
components in the EO. Linalool is the most
abundant oxygenated monoterpene. The fresh
peel and seed were found to contain high
concentration of limonene in all the samples when
compared to air-dried samples, for instance
limonene content in the fresh peel ranged between
88.32 to 90.58% in CP and CS, respectively, while
in fresh seed limonene content ranged between
74.97 – 81.73% for CP and CS, respectively.
Limonene percentage concentration ranged
between 58.64 - 65.95%, respectively for air-dry
peel of CP and CS, while it ranged between 67.92
to 77.30% for CP and CS, respectively for air-dried
seed. Myrcene is another compound that is
present in all the samples and it ranged between
0.08% minimum in C. sinensis dry peel (CSDP) to
maximum of 10.41% in C. paradise fresh seed
(CPFS). Camphene ranged between 0.02 to
4.88%, respectively in CSDP and CPDS. The fresh
peel sample is however higher in limonene content
than the fresh seed. Moreover the fresh peel of CS
was found to contain more number of terpenoids
than CP fresh peel, for instance a-thujene, g-
terpinene, citral and neral were present in C.
sinensis fresh peel (CSFP) but not in C. paradise
fresh peel (CPFP) and the fresh seed of the two
citrus almost have the same number for
terpenoids except linalool that is present in CSFS.
In all the samples, it was observed that air-dried
samples of CS and CP peel have the highest
number of compounds. Compounds like nerol, a-
terpineol, spathulenol and farnesol (alcohol) were
present in these two oils at higher concentration in
C. paradise dry peel (CPDP) than CSDP but were
absent in all the remaining oils. This alcohol
content ranged between 28.91% to 35.81% in CS
and CP, respectively. The general result indicates
that fresh sample has more main components in
Olonisakin Comparative Study of Essential Oil Composition of Fresh and Dry Peel and Seed of Citrus Sinensis:
214
higher concentration than the dry one. This may
be due to the volatile nature of terpenoids during
the course of its drying. The alcohol content that
was not found in the fresh samples was seen in the
dry sample of the citrus most especially the dry
peel.
Table 2: Essential Oil Composition (%) of Fresh and Air-dry Peel and Seed of C.sinensis and C.
paradisi.
Compound
CSFP
%
CPFP
%
CSFS
% CPFS
% CSDP
% CPDP
% CSDS
% CPDS
%
Cymene
-
-
- 2.09 2.26 1.82 1.37
-α-phellandrene
-
-
0.27 0.04 - - 0.03 0.72
α-
terpinene
0.14
1.86 4.00 6.62 0.05 0.06 1.59 3.68
β-ocimene
-
-
0.27 0.02 - - 0.03 0.02
Camphene
0.17
0.05 3.87 3.74 0.02 0.03 1.38 4.88
Terpinolene
-
-
0.22 0.02 - - 0.03 0.02
Sabinine
-
-
0.36 0.03 - - 0.04 0.02
Limonene
90.58
88.32 81.73 74.97 65.95 58.64 77.30 67.92
α-pinene
2.27
2.08 0.93 3.33 - 1.36 3.17 2.31
β-pinene
-
0.01 0.58 0.05 - - 0.08 0.05
Myrcene
5.19
7.00 5.35 10.41 0.08 0.86 2.65 5.04
Thujene
0.10
-
0.21 0.01 0.14 0.16 6.38 6.84
γ-terpinene
0.02
-
0.96 0.90 - - 0.21 0.67
Citral
0.03
-
- - 0.03 0.03 - -
Geranial (nera)
0.49
-
- - 0.57 0.62 - -
Linalool
-
-
0.04 - 8.57 9.27 5.05 6.78
Nerol
-
-
- - 7.96 8.60 - -
α-terpineol
-
-
- - 1.06 1.15 - -
Spathulenol
-
-
- - 9.97 15.13 - -
Farnesol
-
-
- - 1.54 1.66 - -
CSFP = C. sinensis fresh peel, CPFP = C. paradisi fresh peel, CSFS = C. sinensis fresh seed, CPFS = C.
paradisi fresh seed, CSDP = C. sinensis dry peel, CPDP = C. paradisi dry peel, CSDS = C. sinensis dry seed,
CPDS = C. paradisi dry seed.
Olonisakin Comparative Study of Essential Oil Composition of Fresh and Dry Peel and Seed of Citrus Sinensis:
215
Table 3 shows the chemical composition of fresh
CS and CP peel and seed of this study and that of
some fresh peels from other regions of the world.
In all the essential oil under consideration, it was
noticed that limonene, myrcene, pinene and
linalool were present in all the geographical
locations in the order of limonene > myrcene >
pinene. Limonene percentage value ranged
between 74.97- 95.17% in CPFS and Florida
sample (Bauer and Surburk, 2001), respectively
and this is in agreement with Muhammad et al.
(2006) that stated that limonene value of citrus
range between 75- 97%. Myrcene in this study is
higher in percentage concentration (2.09-10.41%)
than the values of other essential oils from other
regions which ranged between 0.90-6.20% in
Turkey and Pakistan, respectively (Burcu et al.,
2011; Muhammad et al., 2006). The alpha pinene in
this study is in higher concentration (0.65 - 3.33%)
than other regions which ranged between 0.42-
1.26% in Florida and Iran, respectively (Burcu et
al., 2011; Parviz et al., 2011).
CONCLUSION
The essential oil yields in dry samples are higher
than the fresh but the percentage concentration of
the major compounds are higher in the fresh than
the dry. Limonene, myrcene, a-terpinene, pinene
and camphene were all present in the oils under
study but when compared with the other region
only camphene were absent in other region but
present in this study. Linalool was found in other
oils from other region but is only on the dry
samples that have linalool in this study with higher
concentration than other regions.
REFERENCES
Asekun, O. T., Grierson, D. S. and Afolayan, A. J.
2006. Influence of drying methods on the
chemical composition and yield of the oil
of Leonotis leonurus. Journal of Scientific
Research and Development 10: 61-64.
Asekun, O. T., Grierson, D. S. and Afolayan, A. J.
2007 Characterization of essential oils
from Helichrysum odoratissimum using
different drying methods. Journal of
Applied Science 7: 1005 - 1008.
Buchel, J.A. 1989. Flavoring with citrus oil.
Perfumer and Flavorist 14: 22–26.
Burcu, U., Fazli, S., Ozgur, A., Birsen, S.O. and
Elif, O. K. 2011 Essential oil composition
and antibacterial activity of the grapefruit
(Citrus paradisi. L) peel essential oils
obtained by solvent-free microwave
e x tr a ct i on : c om p ar i so n w it h
hydrodistillation. International Journal of
Food Science and Technology. 46, 1455–1461.
Colman, R.L., Lund, E.D. and Moshonas, M.G.
1969. Composition of Orange Essence
Table 3: Essential Oil Composition of Fresh Peel and Seed of Present Study and Fresh Peel of Other Region
Compounds
CSFP
%
CSFS
%
CPFP
%
CPFS
%
ITCS
%
FLCS
% TUCS
% PKCP1
% IRCS
% PKCP2
% GRCS
%
α-terpinene
0.14
4.00
1.86
6.62
-
- 1.0 2.11 0.20
- -
Camphene
0.17
3.87
0.05
3.74
-
- - - - - -
Sabinene
-
0.36
-
0.03
1.00 0.24 0.06 - 0.5 - 0.2
Limonene
90.50
81.73
88.32
74.97
93.67 95.17 88.60 86.27 90.50
76.28
94.20
α-Pinene
2.27
0.93
2.08
3.33
0.67 0.42 0.70 1.26 1.40
1.26 0.80
β-Pinene
-
0.58
0.01
0.05
-
- 1.20 - - 5.45 -
Myrcene
5.19
5.35
7.00
10.41
2.09 1.86 0.90 6.28 2.50
1.30 2.80
Thujane
0.10
0.21
-
0.01
-
- - 0.15 - - -
Octanal
-
-
-
-
-
- - - - 0.80 -
linalool
-
0.04
-
-
0.31 0.25 0.70 0.02 0.80
2.32 0.80
3-carene
-
-
-
-
0.31 - 0.50 - - - -
Decanal. - - - - 0.27 o.28 - - - - -
CSFP = C.sinensis fresh peel, CSFS = C. sinensis fresh seed, CPFP = C. paradis fresh peel,
CPFS = C. paradise fresh seed, ITCS = Italian C. sinensis (Verzera et al., 2004), FLCS = Florida C.
sinensis (Vora, 1983), TUCS = Turkey C.sinensis(Burcu, et al., 2011) PKCP1 = Pakistan C. paradisi
1(Muhammad, et al., 2006), IRCS = Iran C. sinensis (Parvizetal,2006), PKCP2 = Pakistan C. paradis 2
(), GRCS = Greece C.sinensis(Filitsa, et al., 2013)
Olonisakin Comparative Study of Essential Oil Composition of Fresh and Dry Peel and Seed of Citrus Sinensis:
216
Oil. Journal of Food Science 34 (6): 610–611.
Davies, F. S. and Albrigo, L. G. 1994. Citrus. CAB
International, Wallingford, 1pp.
Deans, S.G., Svoboda, K.P., Gundidza, M. and
Brechany, E.Y. 1992. Essential oil profiles
of several temperate and tropical aromatic
plants: their antimicrobial and antioxidant
activities. Acta Horticulturae 306: 229–232.
Dharmawan, J., Kasapis, S., Curran, P. and
Johnson, J.R. 2007. Characterization of
volatile compounds in selected citrus
fruits from Asia. Part I: freshly-squeezed
juice. Flavour and Fragrance Journal 22:
228–232.
Filitsa, K., Athanasios, K., Ántonios, M.,
Dimitrios, p., Moschos, P., Panagiota, P.
and Åleanna, T. 2013. Insecticidal activity
of plant essential oils against the vine
mealybug, Planococcus ficus. Journal of Insect
Science 13, Article 142.
Greany, P.D., Styer, S.C., Davis, P.L., Shaw, P.E. and
Chambers, D.L. 1983. Biochemical
resistance of Citrus to fruit flies.
Demonstration and elucidation of
resistance to the Caribbean fruit fly.
Anastrepha suspensa. Entomol. Exp. Appl. 34:
40–50.
Guenther, E. 1948. The Essential Oils. Van
Nostrand-Reinhold. New York, USA.
Jerkovic, I., Mastelic, J. and Milos, M. 2001. The
impact of both the season of collection
and drying on the volatile constituents of
Origanum vulgare L. ssp. hirtum grown wild
in Croatia. International Journal of Food
Science and Technology 36: 649–654.
Jirovetz, L., Buchbauer, G., Stoyanova, A.S.,
Georgiev, E.V. and Damianova, S.T. 2005.
Composition, quality control and
antimicrobial activity of the essential oil
of cumin (Cuminum cyminum L.) seeds from
Bulgaria that had been stored for up to 36
years. International Journal of Food Science and
Technology 40, 305–310.
Kamal, G. M., Anwar, F., Hussain, A. I., Sarri, N.
and Ashraf, M. Y. 2011 Yield and
chemical composition of Citrus essential
oils as affected by drying retreatment of
peels International Food Research Journal
18(4): 1275-1282.
Kustrak, D., Kuftinec, J., Blazevic, N. and Maffei,
M. 1996. Comparison of the essential oil
composition of two subspecies of Satureja
montana. Journal of Essential Oil Research 8:
7–13.
Laranja, D., Mendes, M. F. and Calçada, L. A.
20 03 .I nf l uê nc ia da Sec ag e m na
Composição do Óleo Essencial de
Citronela, II Simpósio Brasileiro de Óleos
Essenciais, IAC, Campinas.
Leung, A.Y. and Foster, S. 1996. Encyclopaedia of
Common Natural Ingredients Used in Foods,
Drugs and Cosmetics, 2nd edn. Wiley.New
York, USA. 465– 466 pp.
Magwa, M.L., Gundidza, M., Gwerua, N. and
Hu m p hre y, G. 20 0 6. C hem i c al
composition and biological activities of
essential oil from the leaves of Sesuvium
portulacastrum. Journal of Ethnopharmacology
103: 85–89.
Matasyoh, J.C., Kiplime, J.J., Karubiu, N.M. and
Hai lstor ks, T.P. 20 07. Che mical
composition and antimicrobial activity of
es se nti al oi l of Ta rchon an t hu s
camphorates. Food Chemistr y 101:
1183–1187.
Milos, M., Mastelic, J. and Jerkovic, I. 2000.
Chemical composition and antioxidant
effect of glycosidically bound volatile
compounds from oregano (Origanum
vulgare L. ssp. hirtum). Food Chemistry 71:
79–83.
Minh Tu, N.T., Thanh, L.X., Une, A., Ukeda, H.
and Sawamura, M. 2002. Volatile
constituents of Vietnamese pummelo,
orange, tangerine and lime peel oils.
Flavour Fragrance Journal 17: 169–174.
Mohamed, A. A, El-Emary, G. A. and Ali, H. F.
2010. Influence of some citrus essential
oils on cell viability, Glutathione-S-
Transferase and Lipid Peroxidation in
Ehrlich ascites carcinoma cells. Journal of
American Science 6 (10):820-826.
Muhammad, M. A., Salim-ur-rehman, Z. I., Faqir,
M.A. and Javaid, I.S. 2006. Genetic
variability of essential oil composition in
four citrus fruit species. Pak. J. Botanical 38
(2): 319-324.
Mukhopadhyay, M. 2000. Natural Extracts Using
Supercritical Carbon Dioxide. CRC Press,
New York, USA.
Muller-Riebau, F., Berge, B. and Yegen, O. 1995.
Chemical composition and fungitoxic
Olonisakin Comparative Study of Essential Oil Composition of Fresh and Dry Peel and Seed of Citrus Sinensis:
217
properties to phytopathogenic fungi of
essential oils of selected aromatic plants
growing wild in Turkey. Journal of
Agricultural and Food Chemistr y 43:
2262–2266.
Njoroge, S.M., Mungal, H.N., Koaze, H., Phi,
N.T.L., and Sawamura, M. 2006.
Volatileconstituents of mandarin Citrus
reticulata Blanco peel oil from Burundi.
Journal of Essential Oil Research 18: 659–662.
Parviz, A.A., Mehdi, N., Kambiz, L. and Sakineh,
B. 2011. Chemical composition of the
essential oils of Citrus sinensis cv. valencia
and a quantitative structure–retention
relationship study for the prediction of
retention indices by multiple linear
regression J. Serb. Chem. Society 76 (12) :
1627–1637
Rahula, O. B. and Wijesekera, A. L. 1973. Varietal
Compositions in the constituents of
citronella oil. Phytochemistry 12: 2697-2708.
Salvatore, A., Borkosky, S., Willink, E. and
Bardo´n, A. 2004. Toxic effects of lemon
peel constituents on Ceratitis capitata. J.
Chem. Ecology 30: 323–333.
Shaw, P. E. 1977. Essential oils. In Citrus Science and
Technology. Nagy S., Shaw P. E. and
Veldhuis M. K. (Eds.). The AVI Publishing
Co. Inc., Westport C.T., 247pp
Sheppard, D.C. 1984. Toxicity of Citrus peel
liquids to the house fly and red imported
fine ant. J. Agric. Entomology 1: 95–100.
Sisko s, E.P., Ko ns ta nt op ou lo u, M.A .,
Mazomenos, B.E. and Jervis, M. 2007.
Insecticidal activity of Citrus aurantium
fruit, leaf and shoot extracts against adults
of the olive fruit flies. J. Econ. Entomology
Pino, J., Sánchez, M., Sánchez, R. and Roncal, E.
2006. Chemical composition of orange oil
concentrates. Nahrung / Food 36 (6):
539–542.
100 (4) : 1215 - 1220
Skocibusic, M., Bezic, N. and Dunkic, V. 2006.
Phy to chemical composition and
antimicrobial activities of the essential oils
from Satureja subspicata Vis. growing in
Croatia. Food Chemistry 96: 20– 28.
Su, H.C.F., Speirs, R.D., Mahany, P.G. 1972.
Toxicity of Citrus oils to several stored-
product insects: laboratory evaluation. J.
Econ. Entomology 65: 1438–1441.
Tu, M.N.T., Onishi, Y. Choi, H.S., Kondo, Y.,
Bassore, S.M.,Ukeda, H. and Sawamura,
M. 2002. Characteristic odor components
of Citrus sphaerocarpa Tanaka (Kabosu)
cold-pressed peel oil. Journal of Agricultural
Food Chemistry 50: 2908-2913.
United States Department of Agriculture (USDA)
(2014). Citrus: world markets trade. Foreign
Agriculture Service of Globe Aalysis
bulletin.
Venkateshwarlu, G. and Selvaraj, Y. 2000. Changes
in the peel oil composition of Kagzi lime
(Citrus aurantifolia Swingle) during
ripening. Journal of Essential Oil Research 12:
50 – 52.
Williams, David G. 1996. The chemistry of essential
oils: Micelle Press, Dorset, England
Verzera, A., Trozzi, A., Dugo, G., Di Bella, G. and
Cotroneo, A. 2000. Biological lemon and
sweet orange essential oil composition.
Flavour and Fragrance Journal 19 (6): 544 –
548
Vora, J. D., Matthews, R. F., Crandall, P. G. and
Cook, R. 1983. Preparation and Chemical
C o mp o s i t i o n of O ra ng e O i l
Concentrates. Journal of Food Science 48 (4):
1197–1199.
Olonisakin Comparative Study of Essential Oil Composition of Fresh and Dry Peel and Seed of Citrus Sinensis:
