Lankondjoa Kolani

Abouwaliou Nafadjara

Essolakina Nadio

Koffi Magnim Bokobana

Christine Koba

Komla Raynaud

Sanda

Nafadjara Abouwaliou Nadio

Essolakina Magnim Bokobana

Koffi Koba

Christine Raynaud

Komla Sanda

Physico-Chemical Attributes of Essential Oil from Zingiber officinale Roscoe and Zingiber zerumbet (L.) Smith Cultivars Grown in Togo

Keywords: Zingiber officinale, Zingiber zerumbet, Rhizome, Essential Oil, Togo

ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

The genus Zingiber, belonging to the Zingiberaceae family, is represented by about 141 species among which are Z. officinale and Z. zerumbet [START_REF] Yob | Zingiber zerumbet (L.) Smith: A Review of Its Ethnomedicinal Chemical and Pharmacological Uses. Evidence-Based Complementary and Alternative Medicine[END_REF]. Both species are perennial herbaceous monocotyledon, usually grown as annual in tropical and subtropical regions [START_REF] Kandiannan | Agronomy of Ginger (Zingiber officinule Rose.): A Review[END_REF]. Z. officinale is well-known as ingredient for dishes in almost tropical and subtropical countries [START_REF] Sultan | Chemical Analysis of Essential Oil of Ginger (Zingiber officinale)[END_REF]. Fresh rhizome is used as for flavoring and taste in different foods during cooking and in formation of compounded aromas for flavoring confectionery, bakery products, condiments, sauces and carbonated beverages while the dried powder is used as spice [START_REF] Sultan | Chemical Analysis of Essential Oil of Ginger (Zingiber officinale)[END_REF]. Z. officinale has been widely used for centuries in traditional medicine for various purposes, such as rhinitis, rheumatism, sprains, muscular aches, pains, sore throats, cramps, constipation, indigestion, vomiting, hypertension, dementia, fever, infectious diseases and helminthiasis [START_REF] Nguta | Antimycobacterial and Cytotoxic Activity of Selected Medicinal Plant Extracts[END_REF]. The essential oil obtained from rhizomes has been reported to exhibit several biological activities, such as antimicrobial [START_REF] Bellik | Total Antioxidant Activity and Antimicrobial Potency of the Essential Oil and Oleoresin of Zingiber officinale Roscoe[END_REF] [6] [START_REF] Mesomo | Supercritical CO 2 Extracts and Essential Oil of Ginger (Zingiber officinale R.): Chemical Composition and Antibacterial Activity[END_REF] [START_REF] Sharma | Chemical Composition and Antimicrobial Activity of Fresh Rhizome Essential Oil of Zingiber officinale Roscoe[END_REF], antioxidant [START_REF] Bellik | Total Antioxidant Activity and Antimicrobial Potency of the Essential Oil and Oleoresin of Zingiber officinale Roscoe[END_REF], and antifungal [START_REF] López | Antimicrobial Activity of Essential Oil of Zingiber officinale Roscoe (Zingiberaceae)[END_REF] [START_REF] Yamamoto-Ribeiro | Effect of Zingiber officinale Essential Oil on Fusarium verticillioides and Fumonisin Production[END_REF]. It contains a mixture of constituents such as monoterpenes, namely phellandrene, camphene, cineole, linalool, limonene, citral, geraniol, citronellol, borneol and sesquiterpenes, namely α-zingiberene, ar-curcumene, β-bisabolene, β-sesquiphellandrene, δ-cadinene, zingiberol and zingiberenol along with some aliphatic aldehydes and alcohols [START_REF] Sharma | Chemical Composition and Antimicrobial Activity of Fresh Rhizome Essential Oil of Zingiber officinale Roscoe[END_REF] [10] [START_REF] Singh | Chemistry, Antioxidant and Antimicrobial Investigations on Essential Oil and Oleoresins of Zingiber officinale[END_REF] [START_REF] Sasidharan | Comparative Chemical Composition and Antimicrobial Activity of Fresh and Dry Ginger Oils (Zingiber officinale Roscoe)[END_REF] [13] [START_REF] Padalia | Leaf and Rhizome Oil Composition of Zingiber officinale Roscoe and Their Antibacterial and Antioxidant Activities[END_REF]. As for Zingiber zerumbet (L.) Smith, it is widely cultivated in the tropics for its medicinal properties and as a marketable spice [START_REF] Saadiah | Proceedings of the National Convention on Herbal Medicine[END_REF]. Among its uses are: treatment for stomachache, swelling, sores and loss of appetite and as an ingredient of several medical preparations used to treat ear inflammation and diarrhea in traditional medicine in many countries [16] [17]. Its rhizomes contain essential oil which is used as medicinal drugs, spices and raw materials for industry [START_REF] Chi | Dictionary of Medicinal Plants in Vietnam[END_REF]. The essential oil is the mixture of terpenes namely zerumbone, α-caryophyllene and camphene [START_REF] Bhuiyan | Chemical Investigation of the Leaf and Rhizome Essential Oils of Zingiber zerumbet (L.) Smith from Bangladesh[END_REF], (Z)-citral, camphene, sabinene, zingiberene and lavandulyl acetate [START_REF] Dai | Chemical Constituents of the Root Essential Oils of Zingiber rubens Roxb. and Zingiber zerumbet (L.) Smith[END_REF], zerumbone, α-humulene, β-selinene and (-)-caryophyllene oxide [START_REF] Ariani | Isolation and Identification of Essential Oils from Bitter Ginger (Zingiber amaricans Bl.), Fragrant Ginger (Zingiber aromaticum Val.) and Shampoo Ginger (Zingiber zerumbet (L.) Smith) Rhizomes Grown in Jumapolo Karanganyar Central Java Indonesia[END_REF]. The composition of volatile oil is highly variable depending upon a variety of factors, in particular the geographical origin [START_REF] Sharma | Essential Oils of Zingiber officinale Roscoe from Northeast India[END_REF] [23] [START_REF] Bartley | Effects of Drying on Flavor Compounds in Australian Grown Ginger (Zingiber officinale)[END_REF]. Hence, this study was undertaken to evaluate the chemical composition of essential oil from rhizomes of Z. officinale and Z. zerumbet cultivated along different parts of Togo.

Material and Method

Plant Material

Samples of the Z. officinale, Z. zerumbet species were collected directly from the main growing areas namely Kougnohou (N: 07.61469 E: 000.79146), Badou (N: 07.60491 E: 000.68892), Danyi Apéyémé (N: 07.16162 E: 000.69497), Kaniamboua (N: 08.364145 et E: 001.001571), Dalanda (N: 08.378180 E: 001.004719), Blitta-Tadjan (N: 08.198874 E: 0.796531) to ensure their origin (Table 1

Moisture Content Measurement of the Rhizomes

The moisture content of the ginger rhizomes was determined according to ASAE Standard S358.2 [START_REF]Moisture Measurement of and Seeds[END_REF]. The sample was dried in an electric oven at a temperature of 105˚C during 24 hours and weighed using a weighing balance. The moisture content of the sample in percent dry basis was calculated using Equation (1).

( ) ( )

100 % i f s f W W M W - = (1)
where: M s is the Moisture Content of Ginger rhizomes (in % dry basis), W i is the Initial Mass of ginger rhizomes before oven drying (in grams) and W f is the Final Mass of the rhizomes after oven drying (in grams).

Physicochemical Analysis of the Essential Oils

The extracted essential oils were evaluated for yield, refractive index and density according to the methods below.

Density Measurement

A volume of approximately five [START_REF] Bellik | Total Antioxidant Activity and Antimicrobial Potency of the Essential Oil and Oleoresin of Zingiber officinale Roscoe[END_REF]

Refractive Index Determination

The refractive index of the different essential oil samples was determined by refractometer HR-110N OPTIKA. One drop of the oil was dropped on the cell compartments of the instruments. The necessary adjustment was made and the result recorded when the lower part became darker [START_REF][END_REF].

Yield Determination

The yield which represents the quantity of essential oil extracted from plant materials was recorded as volume: weight ratio [START_REF] Ayoola | Evaluation of the Chemical Constituents and the Antimicrobial Activity of the Volatile Oil of Citrus reticulata Fruit (Tangerine Fruit Peel) from South West Nigeria[END_REF] [28] [START_REF] Godwin | Physicochemical Properties of Essential Oils of Ginger (Zingiber officinale). African Nutmeg (Monodora myristica) and Ashanti Black Pepper (Piper guineense)[END_REF] ( )

weight of extract recovered Yield % 100 weight of dried plant material = × 2.9. GC-Analysis of Essential Oils

GC/FID Analysis

The simple gas phase analysis was carried out by a Varian 3900 type chromatograph equipped with a flame ionization detector (FID), a non-polar DB-5 ms 30 m × 0.25 mm column; film thickness 0.25 μm df (J&W Scientific). The injector and the detector were maintained at 300˚C. The carrier gas used was helium with a flow rate of 1.6 mL/min. The sample (1 µl) was injected into the column with a split ratio of 1:150. Component separation was achieved following a linear temperature programmed from 60˚C to 180˚C with a gradient of 2˚C/min then increased to 280˚C at 9˚C/min and kept in isothermal at 280˚C for 10 minutes. Percentage of the constituents were calculated by electronic integration of FID peak areas.

GC/MS Analysis

Essential oils were analyzed on an Agilent gas chromatograph Model 6890, coupled to a Agilent MS model 5973, equipped with a DB5 MS column (30 m × 0.25 mm × 0.25 µm film thickness). Essential oils were diluted to 5% in dichloromethane and injected under the following conditions: injector temperature of 300˚C, injection volume 1 μL at a ratio of 1:80 (split mode), initial column temperature of 60˚C; heated gradually to 180˚C at a 2˚C/min rate; heated to 230˚C at a 5˚C/min rate, kept for 5 min. The carrier gas (helium) flow was set at 1.3 mL/min. The temperatures of the transfer line, ion source, and injector were 240˚C, 230˚C, and 300˚C, respectively. The MS works in electron impact mode at 70 eV; electron multiplier, 1500 V. The mass spectra were obtained at a range of mass/load ratio (m/z) 33 -450 in scan mode with a solvent delay time of 3 min. The compounds were identified by comparison of their retention index (RI) obtained using homologous series of n-alkanes standards (C5 -C18) and their mass spectra were compared with the NIST2014 and Wiley2008 library and the literature [START_REF] Sultan | Chemical Analysis of Essential Oil of Ginger (Zingiber officinale)[END_REF]

Results and Discussion

Physico-Chemical Parameters of the Z. officinale and Z. zerumbet Cultivars

The physical parameters (moisture content, essential oil yield, density and refractive index) both for Z. officinale and Z. zerumbet rhizomes samples were found to varied according to the sampling area (Table 2).

The lowest moisture content of Z. officinale rhizomes was observed in samples from Danyi Apéyémé (79.48%) and the highest in samples from Badou (86.59%). The majority of samples (7/8) showed moisture content higher than 80%. The moisture content of studied samples is in similar range with the moisture content reported in Z. officinale rhizomes from Bangladesh (84.97% to 87.98%) [START_REF] Bala | Drying Characteristics of Ginger Rhizome (Zingiber officinale)[END_REF] while it is higher than what reported in Z. officinale rhizomes from India (76.18% -78.84%) [START_REF] Shirsat | Physical Properties of Fresh Ginger (Zingiber officinale) Rhizomes[END_REF]. The essential oil yield varied from 1.25% to 1.67% with the lowest yield obtained in the samples from Kougnohou and the highest yield in the samples from Kaniamboua. Samples from three localities (Kaniamboua, Danyi Apéyémé, Blitta-Tadjan) showed an essential oil yield higher or equal to 1.5%. Steam distillation of Z. officinale essential oil yields 0.2% to 3.0% according to the origin and the state of the rhizome (fresh or dry) [START_REF] Babu | Variability of Exotic Ginger (Zingiber officinale Rosc.) Accessions for Quality Parameters[END_REF] [30] [34] [START_REF] Van Beek | Investigation of the Essential Oil of Vietnamese Ginger[END_REF]. The density of essential oils ranged from 0.876 (Badou) to 0.897 (Blita-Tadjan) and the refractive index from 1.487 (Dalanda and Danyi Apéyémé) to 1.491 (Blitta-Tadjan). Very little variation was observed for the two parameters. The values of 0.877 to 0.883 for density and 1.4884 to 1.4918 for refractive index which are close to our findings were reported in Z. officinale rhizome essential oil samples from Madagascar [START_REF] Koroch | Quality Attributes of Ginger and Cinnamon Essential Oils from Madagascar[END_REF].

Z. zerumbet samples showed moisture content higher than 85% (87.23% to 91.99% respectively for Dalanda and Kaniamboua samples) and an essential oil yield not exceeding 1% (0.75% to 1.00% respectively for the Dalanda and Kaniamboua samples). Crystals uniformly mixed with rhizome oils were observed, giving unsuitable properties to the extract for the determination of the density and the refractive index. Varied yields have been reported elsewhere, namely 0.3% to 0.4% in Z. zerumbet rhizomes from Reunion Island [START_REF] Chane-Ming | Chemical Composition of the Essential Oil from Rhizomes. Leaves and Flowers of Zingiber zerumbet Smith from L. Kolani et al[END_REF]; 0.39% to 0.65% in rhizomes from China [START_REF] Tian | Comparison of Chemical Composition and Bioactivities of Essential Oils from Fresh and Dry Rhizomes of Zingiber zerumbet (L.) Smith[END_REF] and 1.1% in rhizomes from Bangladesh [START_REF] Bhuiyan | Chemical Investigation of the Leaf and Rhizome Essential Oils of Zingiber zerumbet (L.) Smith from Bangladesh[END_REF].

In general, these variations are attributable to many factors such as topological and geographical location as well as maturity of rhizomes, harvesting time, genetic variation, extraction process [10] [22] [39] [40] [START_REF] Usano-Alemanya | Chemical Description and Essential Oil Yield Variability of Different Accessions of Salvia lavandulifolia[END_REF]. Even if both Z. officinale and Z. zerumbet rhizome from Kaniamboua present best potential for essential oil production and commercialization, all sample match international requirement as soon as they yielded higher than 0.4% [START_REF] Marquard | Cultivation and Quality Requirements of Selected Medicinal Plants II[END_REF].

Aromatic Profile of the Z. officinale and Z. zerumbet Cultivars

The aromatic profile of the samples from the different sampling areas is presented in Table 3 Zerumbone was the major oxygenated Sesquiterpenes observed in all the samples and the content varied from 37.5% (Dalanda) to 51.8% (Kaniamboua).

The other oxygenated Sesquiterpenes found in notable amount were trans sesquisabinene hydrate from 4.5% (Dalanda) to 5.5% (Kaniamboua), humulene oxyde from 3.6% (Dalanda) to 4.5% (Kaniamboua), caryophyllene oxyde from 1.9% (Dalanda) to 2.4% (Kaniamboua). The β-eudesmol was found in trace amount (0.1% -0.7%).

The second highest component identified was humulene, a sesquiterpene that was found in amount varying from 21.7% (Dalanda) to 28.2% (Kaniamboua).

Caryophyllene (1.9% -2.6%) and α-zingiberene (0.1% -2.2%) were found in notable amount while β-bisabolene (not detected to 0.7%) and sesquiphellandrene (not detected to 0.9%) was found in trace amounts.

The major components found in Z. zerumbet samples (zerumbone and α-humulene) are different from those reported elsewhere probably due to geographic disparities. (z)-citral, camphene, sabinene and zingiberene were reported as major component in Z. zerumbet sample from Vietnam [START_REF] Dai | Chemical Constituents of the Root Essential Oils of Zingiber rubens Roxb. and Zingiber zerumbet (L.) Smith[END_REF] while zerumbone, α-caryophyllene and camphene were found to be main components in samples from Bangladesh [START_REF] Bhuiyan | Chemical Investigation of the Leaf and Rhizome Essential Oils of Zingiber zerumbet (L.) Smith from Bangladesh[END_REF] and North-East India [START_REF] Singh | Chemical Composition and Biological Activity of the Essential Oil of Rhizome of Zingiber zerumbet (L.) Smith[END_REF]. However, our findings are similar with those reported in Malaysia [START_REF] Malek | Essential Oils of Zingiber ottensii Valet. and Zingiber zerumbet (L.) Sm. from Sabah, Malaysia[END_REF], in India [START_REF] Rana | Chemical Composition of the Essential Oil of Zingiber zerumbet var. darcyi[END_REF], and in Reunion Island [START_REF] Chane-Ming | Chemical Composition of the Essential Oil from Rhizomes. Leaves and Flowers of Zingiber zerumbet Smith from L. Kolani et al[END_REF]. DOI: 10.4236/ajps.2022.1311092 1369 American Journal of Plant Sciences

Conclusion

On the basis of this study, it may be concluded that Z. zerumbet and Z. officinale, growing widely in Togo, can be utilized as the sources of isolation of natu- ral zerumbone and humulene; and zingiberene, basibolene and sesquiphellandrene respectively. Samples from Danyi-Apéyémé (39.7%), Badou (39.9%) and Blitta-Tadjan (39.2%) have comparatively high content of zingiberene which is the major component of Z. officinale while sample from Dalanda (51.8%) has high content of zerumbone which is the major component of Z. zerumbet.

Table 1 .

 1 ). They Sampling areas of Z. officinale and Z. zerumbet rhizomes.

	Cultivar	Sampling areas	Number of samples collected
		Badou
		Danyi Apéyémé
	Z. officinale	Kougnohou Blitta Tadjan	6
		Dalanda
		Kaniamboua
	Z. zerumbet	Dalanda Kaniamboua	2
	TOTAL

Table 2 .

 2 Physical parameters (moisture content, yield, density, refractive index) of Z. officinale and Z. zerumbet rhizomes.

			Rhizomes		Extracts
	Cultivars	Harvest locations	Moisture content (% w/w)	Yield (% w/w)	Density	Refractive index
		Dalanda	82.27	1.33	0.880	1.487
		Kaniamboua	85.46	1.67	0.882	1.489
	Z. officinale	Danyi Apéyémé Badou	79.48 86.59	1.50 1.42	0.881 0.876	1.487 1.490
		Blitta-Tadjan	82.03	1.50	0.897	1.491
		Kougnohou	81.26	1.25	0.878	1.490
	Z. zerumbet	Dalanda	87.23	0.75	ND	ND
	(L.)	Kaniamboua	91.99	1.00	ND	ND

*ND: the crystallization of Z. zerumbet essential oil did not allow to do these measurements.

L.

Kolani

et al. DOI: 10.4236/ajps.2022.1311092 1365 American Journal of Plant Sciences

Table 3 .

 3 for Z. officinale and Table4for Z. Zerumbet. The GC/MS profile of essential oils of Z. officinale showed thirty-eight com-Aromatic profil of Z. officinale L. from six sampling areas in Togo.

	ponents accounting for 92.4%; 90.1%; 91.7%; 92.3%; 91.8% and 93.1% of dry
	rhizome essential oil samples from Dalanda, Kaniamboua, Danyi-Apéyémé, Ba-
	dou, Blitta-Tadjan and Kougnohou respectively. Essential oil from all sampling
	areas showed high predominance of sesquiterpenes (69.9% to 80.2%) and mo-
	noterpenes (5.9% to 13%), while oxygenated monoterpenes (2.6% to 5.2%) and
	oxygenated sesquiterpenes (2% to 3.3%) were found in low level. The highest
	content of sesquiterpenes, monoterpenes, oxygenated monoterpenes and oxy-
	genated sesquiterpenes were found respectively in the samples from Badou
	(80.2%), Danyi Apeyeme (13%), Kaniamboua (5.2%) and Dalanda (3.3%) while
	the lowest levels were found in samples from Kaniamboua (69.9%), Dalanda and
	Badou (5.9%), Danyi Apeyeme (2.6%) and Kaniamboua (2%).
	Zingiberene was the major sesquiterpene identified in the essential oil of all
	the samples. The higher zingiberene content was registered in Badou samples
	(39.9%) followed by Danyi-Apéyémé (39.7%) and Blitta-Tadjan (39.2%) while
	the lower content was found in Kaniamboua samples (33%). Basibolene (12.7%
	to 16%) and sesquiphellandrene (13% to 14.7%) was the second highest compo-
	nent in all the rhizomes sampled. Basibolene content was highest in Badou sam-
	ples (16.0%) while the lowest content was recorded in Kaniamboua samples
	(12.7%). Sesquiphellandrene content did not vary widely, and the highest was
	observed both in Badou and Blitta-Tadjan samples (4.7%) while the lowest was
	found in Kaniamboua samples (13.0). The other major sesquiterpene was α-
	curcumene which ranged from 5.8% (Dalanda) to 4.5% (Danyi-Apéyémé), but
	was absent in Blitta-Tadjan samples. The γ-murolene content varied from 1.0%
	(Kaniamboua) to 4.7% (Blitta-Tadjan) and was absent in Danyi-Apéyémé and
	Badou samples. The germacrene was also present in notable amount in all sam-

ples and varied from 1.6% (Kaniamboua) to 2.4% (Kougnohou). The β-farnesene content just get over 1% in Dalanda samples while it was below 1% in other samples.

L.

Kolani

et al. DOI: 10.4236/ajps.2022.1311092 1366 American Journal of Plant Sciences

Table 4 .

 4 Aromatic profil of Z. zerumbet L. from two sampling areas in Togo.

	Peak N˚	Component	Sampling areas and content (%) Dalanda Kaniamboua	IR/MS	Identification
	Monoterpenes	1.8	3
	1	α-pinene	0.3	0.4	931	MS, RI
	2	camphene	1.3	2.3	948	MS, RI
	3	3 carene	0.2	0.3	1010	MS, RI
	Oxygenated Monoterpenes	1	2.4
	4	eucalyptol	0.6	1.1	1032	MS, RI
	5	camphor	0.4	1.3	1148	MS, RI
	Sespuiterpenes	27.7	30.9
	6	caryophyllene	1.9	2.6	1411	MS, RI
	7	humulene	21.7	28.2	1450	MS, RI
	8	α-curcumene	0.3	_	1481	MS, RI
	9	α-zingiberene	2.2	0.1	1493	MS, RI
	10	β-bisabolene	0.7	_	1507	MS, RI
	13	sesquiphellandrene	0.9	_	1522	MS, RI
	oxygenated Sesquiterpenes	61.9	50.6
	15	caryophyllene oxyde	1.9	2.4	1575	MS, RI
	16	trans sesquisabinene hydrate	4.5	5.5	1593	MS, RI
	18	humulene oxyde	3.6	4.5	1604	MS, RI
	25	β-eudesmol	0.1	0.7	1654	MS, RI
	31	zerumbone	51.8	37.5	1737	MS, RI
		Total (%)	92.4	86.9

Acknowledgements

The authors are grateful to Centre de Ressource Technologique CATAR de Toulouse for GC/FID and GC/MS analysis of essential oils.

Conflicts of Interest

The authors declare no conflicts of interest regarding the publication of this paper.