Extraction and characterization of essential oil of garlic (Allium Sativa L.)

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International Journal of Chemical Studies 2021; 9(1): 1455-1459
P-ISSN: 2349–8528
E-ISSN: 2321–4902
www.chemijournal.com
IJCS 2021; 9(1): 1455-1459
© 2021 IJCS
Received: 12-10-2020
Accepted: 23-11-2020
Nilesh Dehariya
Department of Agricultural and
Food Engineering, Indian
Institute of Technology
Kharagpur, West Bengal, India
Proshanta Guha
Department of Agricultural and
Food Engineering, Indian
Institute of Technology
Kharagpur, West Bengal, India
Rakesh Kumar Gupta
Department of Agricultural and
Food Engineering, Indian
Institute of Technology
Kharagpur, West Bengal, India
Corresponding Author:
Nilesh Dehariya
Department of Agricultural and
Food Engineering, Indian
Institute of Technology
Kharagpur, West Bengal, India
Extraction and characterization of essential oil of
garlic (Allium sativa L.)
Nilesh Dehariya, Proshanta Guha and Rakesh Kumar Gupta
DOI: https://doi.org/10.22271/chemi.2021.v9.i1u.11426
Abstract
The essential oil was extracted from garlic powder by soxhlet extraction method using ethanol as a
solvent. The yield of essential oil was influenced by extraction time and temperature. The maximum
extraction yield was 16.55% under treatment- T7 (50 °C for 4 hours). The density and refractive index of
the oil was 0.875 (g/ml) and 1.52 respectively. The oil is light yellowish in colour with a pungent odour.
The maximum TOAC (12.01 mM α tocopherol per ml of essential oil) was found under T3 treatment.
Essential oil was analyzed by gas chromatography–mass Spectrometry (GC-MS). The major chemical
compound were: diallyl disulfide (48.42%), allyl methyl trisulfide (7.27%), trisulfide, di-2 propenyl
(3.46%), and daillyl sulfide (7.64%). The results revealed that T7 was the best treatment among all
treatments. This indicates the feasibility of garlic oil production at a commercial scale for culinary and
medical utilization.
Keywords: Garlic essential oil, chemical composition, refractive index, TOAC, Allium sativum
1. Introduction
Allium sativum L., commonly known as garlic, belongs to the onion family, lilliaceae. Garlic
was likely originated in Central Asia and it has been in use throughout the world for both
culinary and medicinal purposes [1, 2]. The garlic oil, rich in sulfureted organic compounds,
contains a variety of sulfides such as diallyl disulfide and dilly trisulfide [3-7]. It is used not only
as a flavoring agent, food preservative but also in the prevention and treatment of several
illnesses [8, 9]. In the pharmaceutical industry, it is much used due to its anticarcinogenic,
antithrombotic and antiplatelet aggregation properties. The regular consumption of garlic oil
can reduce blood pressure, prevent heart disease including atherosclerosis, high cholesterol
and cancer [10]. Recent biological and pharmacological research [11-21] confirms these medicinal
properties showing that garlic oil has an antibiotic, antioxidant, anti-viral, anti-fungal,
antimicrobial, anticarcinogenic and immunomodulatory effect and garlic can be used to
prevent nausea, diarrhea, ease coughs and even in treatment in conditions such as malaria and
cholera. It is an immune system enhancer [22]. Some studies have found lower rates of certain
types of cancer in people who use it regularly.
Being the second largest producer of garlic, India maintains surplus quantify most of the times
that remains unutilized. India provides 5.2% of the total world production followed by China
with 80% share in the global market. The other major producers are Bangladesh and Egypt
followed by Korea, Russia and others. In India Madhya Pradesh, Rajasthan, Gujarat, Orissa,
Uttar Pradesh and Maharashtra are the main states where garlic is grown commercially with an
average yield of 6-8 tonnes/ha. Madhya Pradesh is the leading garlic producing state with the
production of 4.24 lakh tones accounting to about 26.25% of total Indian production and a
yield of 7.86 tonnes/ha.
In India, due to lack of poor post-harvest handling practices, suitable storage, processing
facilities, heavy losses are incurred both in terms of quality and quantity. This may be
attributed to respiration, transpiration and microbiological spoilage. Though garlic is produced
abundantly and consumed as such, little efforts have so far been made to produce garlic
essential oil from garlic powder. Garlic is a semi perishable commodity and nearly 30% of the
crop is wasted due to respiration and microbiological spoilage during storage [23], which needs
to be addressed. Therefore, it is important to diversify its utility forms.

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International Journal of Chemical Studies http://www.chemijournal.com
Extraction of essential oil is a major food processing
operation in the food industry for utilization of this surplus
garlic in terms of value addition and income generation and
thereby minimize wastage.
There are different methods for extraction of essential oil. In
this study, the essential oil was extracted by soxhlet extraction
method using ethanol as a solvent. This study had four
objectives: 1) Optimization of a process parameter, 2)
Determination of physical properties, 3) To find out chemical
composition of the extracted oil, 4) Evaluation of antioxidant
capacity.
2. Materials and Methods
Fresh garlic (local variety) was procured from Tech market,
IIT Kharagpur and during the experiments, all the samples
were stored in our lab at appropriate conditions (dark, 27 ºC).
The garlic cloves were cut into two equal-size manually by
stainless steel knife with the utmost care and immediately
kept into the oven at 60˚C to dry for 48 hours and the powder
was made by mechanical tools.
2.1. Extraction of Essential Oil
The solvent extraction method was conducted with a soxhlet
extractor using commercial ethanol at different temperature of
50, 60 and 70°C for 2, 3 and 4 hours. The combination of
temperature and time were determined in a preliminary set of
experiments. Three replicates were carried out for all nine
treatments to reduce the error. Garlic powder was used (10g)
at 1:20, sample to solvent ratio. The oil was obtained after the
solvent was evaporated by placing over a water bath
(LABARD, LI-WBPR-14A) for about 2-3 hours under
reduced temperature (50°C) and refluxing at 70°C to remove
any excess solvent [2]. The extracted garlic oil was stored in a
refrigerator at 4°C for subsequent physico-chemical analyses.
2.2. Antioxidant Activity
The total antioxidant capacity (TAOC) of the essential oil
samples was measured as previously described [24]. Briefly,
40µl of essential oil was mixed with a reagent solution (0.6 N
sulphuric acid, 28 mM sodium phosphate, and 4 mM
ammonium molybdate) in an Eppendorf tube in the ratio of
1:100 (v/v) and the tubes were capped and incubated at 95°C
for 90 minutes. The addition of essential oil to the reagent
solution caused discoloration after incubation. This indicates
the scavenging capacity of essential oil. Samples were cooled
at room temperature and absorbance was measured at 695 nm
using a spectrophotometer (Epoch 2, BioTek, U.S.A.). All
determinations were performed in duplicate. TAOC of the
samples were expressed as equivalents of mM-α‐tocopherol
per ml of essential oil and was calculated as follows:
A= €CL
Where
A= Absorbance
€= Extinction co-efficient (4×103 M-1 cm-1)
C= Concentration (molar)
L= Path length (1 cm)
2.3. Chemical Composition
The volatile oil extracted from garlic powder was subjected to
GC-MS analysis as previously described [25-32]. A GC-MS
(Thermo Scientific, Trace 1300), GC (TRACE-GC ULTRA)
and MS (POLARISQ) instrument was used to study the
composition of extracted essential oil. This instrument was
operated in the electron impact (EI) mode set at electron
energy 70eV and a scan range of 0.00 amu–100 amu, with a
scan rate of 3.0 scans per second. DB-5MS column of 30 m
length with 0.25 mm inner diameter was used. Helium gas
(99.99%) was used as a carrier at a constant flow rate of 1 ml
min-1 on the column head. The temperature of the injector
was set at 250 ◦C and the temperature of the ion source was
set at 230 ºC. The temperature of the GC oven was
programmed to be 50 ºC initially and was programmed to
increase at a rate of 5 ºC/min to a final temperature of 260 ºC.
The sample was prepared by diluting the essential oil in a
ratio of 1:10 with methanol and 1.0 µl volume of sample was
injected into the instrument with a split ratio of 30:1.
The obtained mass spectra were thoroughly screened and
individual components of essential oils were quantified by
relative peak percent area. Identification of each quantified
components was done by comparing their mass fragmentation
pattern with components stored in the spectrometer database
using NIST mass spectral library (Version 2014).
2.4 Removal of Milky Emulsion and Excess Solvent
Since the milled substrate showed a tendency to agglomerate
during extraction, optimal particle size was determined in a
preliminary set of experiments as the smallest that did not
cause perceptible agglomeration problems and this size was 1-
3 mm. Some essential oil extracted with milky emulsion (Fig.
1) was centrifuged at 3000 rpm for 5 minutes by a high-speed
refrigerated research centrifuge –RC 4100 F. By this, the
milky emulsion stuck around the surface of the bottle and
clean essential oil including solvent was separated by pipet,
then placed in a water bath for removing excess solvent.
Fig 1: Essential oil + Solvent+ Emulsion
3. Results and Discussion
3.1. Yield of Garlic Oil
The yield of garlic essential oil changed with the process
temperature, and time (Table 1). The best treatment for this
research work was T7 (50°C for 4 hour). The maximum
extraction yield was 16.55% (db) among the nine treatments.
By optimizing the process parameter, the best combination of
the parameters were found to be 4 hours and 50°C. These
parameters can be ideal one to obtain the maximum yield at a
commercial level. Thus, in the present study much higher oil
yield was obtained compare to that reported by Ali Rafe et al.
2014 [33]. They found that maximum yield were 5.5, 6 and 7%
for steam distillation, solvent method and SCF-CO₂,
respectively.

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Table 1: Extraction yield %
Treatment
Time (h)
Temperature (°C)
Yield (%)
T1
2
50
7.55
T2
2
60
9.33
T3
2
70
11.88
T4
3
50
14.55
T5
3
60
13.55
T6
3
70
13.75
T7*
4
50
16.55
T8
4
60
15.88
T9
4
70
15.33
3.2. Physical properties
The Physical examination of the extracted oil was conducted
and presented in Table 2. The properties were moisture
content, density, refractive index, appearance and odour. The
moisture content of the peeled garlic cloves was (63.14±1%).
The density and refractive index were 0.875±1 (g/ml) and
1.52 at room temperature which falls within the range of
volatile oil in general. The appearance of extracted oil was
light yellowish and it had pungent odour.
Table 2: Physical properties of extracted garlic essential oil
Parameters
Results
Moisture content (%)
63.14±0.38
Density (g/cm3)
0.873±0.003
Refractive index
1.52±0.02
Appearance
Light yellow
Odour
Pungent
Oil yield (%)
16.55±0.33
3.3. Chemical Composition of Extracted Oil
The essential oil compositions were determined by GC-MS.
The qualitative and quantitative differences of compounds are
presented in Table 3. The total ion chromatogram of garlic
essential oil is shown in Fig. 3. The major compounds in the
extracted oil were diallyl disulfide (48.42%), allyl methyl
trisulfide (7.27%), trisulfide, di-2 propenyl (3.46%) and
daillyl sulfide (7.64%). There was some loss of volatile
compounds of essential oil, may be during oven drying of
garlic slices. Indeed these chemical compounds covered more
than 85% of GC profile. Sulfide compound was dominated
among all compounds. This result is slightly different from
other authors (Douiri et al. 2013) [34] who reported that garlic
essential oil obtained by Clevenger hydrodistillation
contained diallyl disulfide (16.0%) and allyl methyl trisulfide
(10.9%). Similarly, Rao et al. 2007 [35] have analyzed six
geographical varieties of essential oils extracted by steam
distillation from fresh garlic grown in India and found that
diallyl disulfide (27.1–46.8%) and diallyl trisulfide (19.9–
34.1%) dominated in the oil followed by allyl methyl
trisulfide (8.3–18.2%) and allyl methyl disulfide (4.4–12.0%).
It can be expected that this oil may be commercialized for
medicinal purposes in view of its reported prophylactic and
curative profile.
Table 3: Results of GC-MS analyses of extracted oil
RT (min)
Compounds
Composition %
34.91
Diallyl disulfide,
48.42%
3.28
Daillyl sulfide
7.64%
22.44
Ally methyl trisulfide
7.27%
17.25
Trisulfide, di-2 propenyl
3.46%
55.94
Hydrazine, methyl
5.75%
56.24
2-Propanone, 1-hydroxy
5.81%
51.10
1, 2-Cyclopentanedione
1.24%
53.43
Cyclopropane carboxylic acid 1-amino
0.52%
52.95
Benzoic acid, 2-methyl
3.22%
58.08
3-Vinyl-1, 2-dithiacyclohex-5-en
1.13%
54.17
1H-Pyrrole, 1-methyl
0.75%
Fig 2: Total ion chromatogram of the garlic essential oil (peak assignments are given in table)
3.4. Antioxidant capacity
The total antioxidant capacity of essential oil was analyzed
for each treatment and presented in Fig. 2. The maximum
total antioxidant capacity was 12.018 mM α tocopherol per ml
of essential oil for T3 treatment (70 °C for 2 hours). The
results indicate that for a specific duration of time with every
10 °C rises in temperature there was an increase in
antioxidant activity. It may be due to phenolic compound and
the sulfur compound was more active at 70 °C temperature as
compare to 50 °C and 60 °C temperature or these compound
may be extracted more at 70 °C.

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International Journal of Chemical Studies http://www.chemijournal.com
Fig 3: Effect of temperature and time on total antioxidant capacity
4. Conclusions
This study has demonstrated that there is a significant impact
of temperature and time on the yield of essential oil. The best
parameters are 4 hours and 50°C for obtaining the maximum
yield. These parameters can be considered as an ideal one for
commercial production. The physical properties i.e. moisture
content, density, refractive index, appearance and odour were
within the range of essential oil. The refractive index of
extracted oil can be used for its identification from other
edible oil sources. These properties indicates the feasibility of
garlic oil production for commercial purposes. The extracted
oil was found to be a very good antioxidant and it can not
only be used for food preservation but also for prophylactic
and therapeutic uses. The principal chemical compounds
detected were: diallyl disulfide (48.42%), allyl methyl
trisulfide (7.27%), trisulfide, di-2 propenyl (3.46%), and
daillyl sulfide (7.64%). Sulfide compound dominated among
the all compounds. It can be expected that this oil can be
commercialized for medicinal and culinary purposes.
5. Acknowledgements
The authors are grateful to the Indian Institute of Technology
Kharagpur for financial assistance, infrastructure and facilities
to conduct the research. They are also thanks to Dr. D. K.
Swain, Prof. S. L. Srivastava, Mr. Sujosh Nandi, Mr. Jagan
Kartik S, Ms. Mitali Madhumita and Ms. Kalyani Hemraj
Burde, of Agricultural and Food Engineering Department, IIT
Kharagpur for their continued support.
6. COI Statement: The authors declared that they have no
conflict of interest
7. References
1. McGee H. On food and cooking: the science and lore of
the kitchen. Simon and Schuster 2007.
2. Gafar MK, Itodo AU, Warra AA, Abdullahi L. Extraction
and physicochemical determination of garlic (Allium
sativum L) oil. Int J Food Sci Nutr 2012;1(2):4-7.
3. Huang Y, Chen SX, Ho SH. Bioactivities of methyl allyl
disulfide and diallyl trisulfide from essential oil of garlic
to two species of stored-product pests, Sitophilus zeamais
(Coleoptera: Curculionidae) and Tribolium castaneum
(Coleoptera: Tenebrionidae). Journal of Economic
Entomology 2000;93(2):537-543.
4. Jo KS, Kim HK, Ha JH, Park MH, Shin HS. Flavor
compounds and storage stability of essential oil from
garlic distillation. Korean Journal of Food Science and
Technology 1990;22(7):840-845.
5. Kim JW, Kim YS, Kyung KH. Inhibitory activity of
essential oils of garlic and onion against bacteria and
yeasts. Journal of food protection 2004;67(3):499-504.
6. Satyal P, Craft JD, Dosoky NS, Setzer WN. The chemical
compositions of the volatile oils of garlic (Allium
sativum) and wild garlic (Allium vineale). Foods
2017;6(8):63.
7. Lawrence R, Lawrence K. Antioxidant activity of garlic
essential oil (Allium sativum) grown in north Indian
plains. Asian Pacific Journal of Tropical Biomedicine
2011;(z1):51-54.
8. Seydim AC, Sarikus G. Antimicrobial activity of whey
protein based edible films incorporated with oregano,
rosemary and garlic essential oils. Food research
international 2006;39(5):639-644.
9. Del Valle JM, Mena C, Budinich M. Extraction of garlic
with supercritical CO2 and conventional organic
solvents. Brazilian Journal of Chemical Engineering
2008;25(3):532-542.
10. Avato P, Tursi F, Vitali C, Miccolis V, Candido V.
Allylsulfide constituents of garlic volatile oil as
antimicrobial agents. Phytomedicine 2000;7(3):239-243.
11. Benkeblia N. Antimicrobial activity of essential oil
extracts of various onions (Allium cepa) and garlic
(Allium sativum). LWT-food science and technology
2004;37(2):263-268.
12. Cavallito CJ, Bailey JH, Buck JS. The antibacterial
principle of Allium sativum. III. Its precursor and
essential oil of garlic. Journal of the American Chemical
Society 1945;67(6):1032-1033.
13. Casella S, Leonardi M, Melai B, Fratini F, Pistelli L. The
role of diallyl sulfides and dipropyl sulfides in the in vitro
antimicrobial activity of the essential oil of garlic, Allium
sativum L., and leek, Allium porrum L. Phytotherapy
Research 2013;27(3):380-383.
14. Corzo-Martínez M, Corzo N, Villamiel M. Biological
properties of onions and garlic. Trends in food science &
technology 2007;18(12):609-625.
15. Dziri S, Casabianca H, Hanchi B, Hosni K. Composition
of garlic essential oil (Allium sativum L.) as influenced

~ 1459 ~
International Journal of Chemical Studies http://www.chemijournal.com
by drying method. Journal of Essential Oil Research
2014;26(2):91-96.
16. Edris AE, Fadel HM. Investigation of the volatile aroma
components of garlic leaves essential oil. Possibility of
utilization to enrich garlic bulb oil. European Food
Research and Technology 2002;214(2):105-107.
17. Kim JW, Huh JE, Kyung SH, Kyung KH. Antimicrobial
activity of alk(en)yl sulfides found in essential oils of
garlic and onion. Food Science and Biotechnology
2004;13(2):235-239.
18. Moreno FJ, Corzo-Martı M, Del Castillo MD, Villamiel
M. Changes in antioxidant activity of dehydrated onion
and garlic during storage. Food Research International
2006;39(8):891-897.
19. Romeilah RM, Fayed SA, Mahmoud GI. Chemical
compositions, antiviral and antioxidant activities of seven
essential oils. J Appl Sci Res 2010;6(1):50-62.
20. Bozin B, Mimica-Dukic N, Samojlik I, Goran A, Igic R.
Phenolics as antioxidants in garlic (Allium sativum L.,
Alliaceae). Food chemistry 2008;111(4):925-929.
21. Sharma GP, Prasad S, Chahar VK. Moisture transport in
garlic cloves undergoing microwave-convective drying.
Food and bioproducts processing 2009;87(1):11-16.
22. Bagudo BU, Acheme OD. Chemical analysis of locally
cultivated garlic and it's oil. Der Chemica Sinica
2014;5(1):128-134.
23. Prieto P, Pineda M, Aguilar M. Spectrophotometric
quantitation of antioxidant capacity through the
formation of a phosphomolybdenum complex: specific
application to the determination of vitamin E. Analytical
biochemistry 1999;269(2):337-341.
24. Arabshahi-Delouee S, Urooj A. Antioxidant properties of
various solvent extracts of mulberry (Morus indica L.)
leaves. Food chemistry 2007;102(4):1233-1240.
25. Andreatta AE, Foco G, Mabe G, Bottini SB. Extraction
of garlic oil with Quasi-Critical Solvents. Enproma,
Argentina 2005, 1-9.
26. Avato P, Miccolis V, Tursi F. Agronomic evaluation and
essential oil content of garlic (Allium sativum L.)
ecotypes grown in Southern Italy. Advances in
horticultural science 1998, 201-204.
27. Calvo-Gómez O, Morales-López J, López MG. Solid-
phase microextraction– gas chromatographic-mass
spectrometric analysis of garlic oil obtained by
hydrodistillation. Journal of Chromatography A
2004;1036(1):91-93.
28. Jirovetz L, Jäger W, Koch HP, Remberg G.
Investigations of volatile constituents of the essential oil
of Egyptian garlic (Allium sativum L.) by means of GC-
MS and GC-FTIR. Zeitschrift für Lebensmittel-
Untersuchung und Forschung 1992;194(4):363-365.
29. Kimbaris AC, Siatis NG, Daferera DJ, Tarantilis PA,
Pappas CS, Polissiou MG. Comparison of distillation and
ultrasound-assisted extraction methods for the isolation
of sensitive aroma compounds from garlic (Allium
sativum). Ultrasonics sonochemistry 2006;13(1):54-60.
30. Grewal JS, Alam MS, Ubhi GS. Optimization of Process
Parameters for Convective-cum-microwave Dehydration
of Garlic Slices (Allium sativum L.). International Journal
of Engineering Science Invention 2014;3:46-55.
31. Li R, Chen WC, Wang WP, Tian WY, Zhang XG.
Extraction of essential oils from garlic (Allium sativum)
using ligarine as solvent and its immunity activity in
gastric cancer rat. Medicinal Chemistry Research
2010;19(9):1092-1105.
32. Sharma GP, Prasad S. Optimization of process
parameters for microwave drying of garlic cloves.
Journal of Food Engineering 2006;75(4):441-446.
33. Rafe A, Nadjafi MS. Physicochemical characteristics of
garlic (Allium sativum L.) oil: Effect of extraction
procedure. International Journal of Nutrition and Food
Sciences 2014;(3):6-1.
34. Douiri L, Boughdad A, Assobhei O, Moumni M.
Chemical composition and biological activity of Allium
sativum essential oils against Callosobruchus maculatus.
IOSR J Environ. Sci. Toxicol. Food Technol 2013;3:30-
36.
35. Rao PP, Nagender A, Rao LJ, Rao DG. Studies on the
effects of microwave drying and cabinet tray drying on
the chemical composition of volatile oils of garlic
powders. European Food Research and Technology
2007;224(6):791.