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Angers, P., M.R. Morales, and J.E. Simon. 1996. Basil
seed oils. p. 598-601. In: J. Janick (ed.), Progress in new crops. ASHS
Press, Arlington, VA.
Basil Seed Oils*
Paul Angers, Mario R. Morales, and James E. Simon
- METHODOLOGY
- RESULTS
- REFERENCES
- Table 1
- Table 2
The genus Ocimum (Lamiaceae), which includes sweet basil, offers a wide
diversity among its more than 50 species (Bailey 1924; Darrah 1980),
particularly regarding plant growth, morphology, physical appearance and
essential oil content and composition (Morales et al. 1993; Simon et al. 1984).
Seed oil composition constitutes another characteristic which contributes to
the rich diversity of the Ocimum genus.
Previous studies on basil seed oils include the drying properties of O.
basilicum (Earle et al. 1960), O. kilimandscharicum (Barker et al.
1950; Henry and Grindley 1944), and O. sanctum (Nadkarni and Patwardhan
1952); the isolation of the compounds in seed oil that might be responsible for
medicinal properties (Metha and Metha 1943); and the suitability of O.
basilicum seed oil for cosmetic uses (Domokos and Perédi 1993). In
this paper, we analyzed the chemical composition and characterized the physical
properties of the fixed oil from seeds of four Ocimum species: O.
basilicum, O. canum, O. gratissimum, and O. sanctum.
Mature dry seeds of seven basil chemotypes: citral, linalool, methyl chavicol,
and methyl cinnamate (O. basilicum); camphor (O. canum); eugenol
(O. sanctum); and geraniol (O. gratissimum ), from our breeding
program at Purdue University, were washed and finely ground in a mortar.
Classification of O. canum should be considered temporary due to
possible interspecific hybridization. The oil from the flour was extracted in
a Butt-type apparatus following A.O.C.S. recommendations (Link, 1973). The
extract was concentrated under a stream of dry nitrogen or argon for
quantitative determination of the oil content. Transesterification of acylated
fatty acids was carried out with 2.0 N sodium hydroxide in dry methanol
(Pelick and Mahadvan 1975). Iodine values (Hanus method) and saponification
values were both measured according to AOAC (Cunniff 1995). Refractive indices
were measured at 20deg.C with a refractometer (Bausch and Lomb, Rochester, NY),
coupled with a controlled temperature bath and circulator (Forma Scientific
model 2067, Marietta, Ohio). Methyl esters and glycerides were analyzed by gas
chromatography, as described in Angers et al. (1996).
Oil content and characteristics of basil seeds evaluated in this study compared
to linseed are shown in Table 1 and values reported in the literature are
presented in Table 2. Oil content in the seeds averaged 22%, with a minimum of
18% in the camphor chemotype (O. canum) and a maximum of 26% in the
linalool chemotype (O. basilicum). While the oil content of these
basils is lower than that found in many commercial oil plants such as rape
(Brassica napus L., 38%-44%) and linseed (flax, Linum
usitatissimum L., 32%-43%), the actual physico-chemical and fatty acid
profiles approached that of linseed oil. The refractive indices (1.460-1.481),
saponification (191-200) and iodine values (172-200, Hanus) were all
characteristic of highly unsaturated oils. The oils were very high (96% among
all basils) in triacylglycerols (TAG), while the total for both mono- and
diacylglycerols reached only 2% each. TAGs with carbon number (CN) 54
constituted 70%-84% of the total TAGs; with CN 52, 15%-27%; and with CN 50,
1%-3%. TAGs with CN 48 and 56 constituted less than 1% each.
Unsaturated fatty acids averaged 89%, including [[alpha]]-linolenic (43.8% to
64.8%), linoleic (17.8% to 31.3%), and oleic (8.5% to 13.3%). The most
abundant saturated fatty acids were palmitic (6.1% to 11.0%) and stearic (2.0%
to 4.0%). Values from the literature (Table 2) range from 5.3% to 15.4% for
oleic acid, 14.0% to 66.1% for linoleic acid, and 15.7% to 65.0% for linolenic
acid (Patwardhan 1930; Henry and Grindley 1944; Barker et al. 1950; Nadkarni
and Patwardhan 1952; Earle et al. 1960; Khan et al. 1961). The total of
linoleic and linolenic acids appears to be fairly constant for all species,
ranging from 78% to 82%, except in O. sanctum where it reached only
71%.
The composition of basil seed oil suggests that the oil would be suitable for
industrial purposes, much in the same way as linseed oil is used. An estimated
basil seed yield in Indiana of 1400 kg/ha at 22% seed oil, would yield 300
kg/ha of oil, or 180 kg/ha of linolenic acid. In contrast, seed yields of flax
averaged 765 kg/ha (FAO 1995) and at a 40% oil content, the estimated yield of
linolenic acid from flax (linseed) is 150 kg/ha.
Techniques and conditions for basil cultivation are well known, as the plant
has been grown as a culinary herb and source of essential oil for many years.
Seed and oil content yields could be increased by plant selection. Seeds of
basil do not readily dehisce and can be harvested using a combine. A high
linolenic acid oil, such as that found in Ocimum basilicum and O.
canum, could be used in the paint, varnish and ink industries, and as a
source of linolenic acid, while oils with lower linolenic acid content, such as
those of O. gratissimum and O. sanctum, might be used by the food
industry.
- Angers, P., M.R. Morales, and J.E. Simon. 1996. Fatty acid variation in seed
oil among Ocimum species. J. Am. Oil Chem. Soc. 73:393-395.
- Bailey, L.H. 1924. Manual of cultivated plants. MacMillan, New York.
- Barker, C., H.C. Dunn, and T.P. Hilditch. 1950. African drying oils. V. Some
Nigerian and Sudanese drying oils. J. Soc. Chem. Ind. 69:71-75.
- Bernardini, E. 1985. Vegetable oils and fats processing, BE. Oil, Rome, p.16.
- Cunniff, P. (ed.). 1995. Official methods of analysis of the association of
official analytical chemists, 16th ed., Association of Official Analytical
Chemists, Methods 920.158 and 920.160.
- Darrah, H.H. 1980. The cultivated basils. Buckeye Printing, Independence, MO.
- Domokos, J. and J. Perédi. 1993. Studies on the seed oils of basil
(Ocimum basilicum L.) and summer savory (Satureja hortensis L.).
Acta Hort. 344:312-314.
- Earle, F.R., R.A. McGuire, J. Mallan, M.O. Bagby, and I.A. Wolff. 1960. Search
for new industrial oils. II. Oils with high iodine values. J. Am. Oil Chem.
Soc. 37:48-50.
- FAO 1995. Production yearbook 1994, 48:114: Rome.
- Henry, A.J. and D.N. Grindley. 1944. The oils of the seeds of Ocimum
kilimandscharicum, Euphorbia calycina, E. erythraeae,
Sterculia tomentosa, and Trichilia emetica. J. Soc. Chem. Ind.
63:188-190.
- Khan, S.A., M.I. Qureshi, M.K. Bhatty, and Karimulah. 1961. Composition of the
seed oils of Salvia spinosa and Ocimum pilosum (O.
Basilicum). Pakistan J. Sci. Res. 13:41-43.
- Link, W.E. (ed.). 1973. Method Aa. p. 4-38. In: Official methods and
recommended practices of the Am. Oil Chem. Soc., 3rd ed., Am. Oil Chem. Soc.,
Champaign, IL.
- Mehta, C.R. and T.P. Metha. 1943. Chemical examination of Ocimum canum
Sims. Current Sci. 12:300-301.
- Morales, M.R., D.J Charles, and J.E. Simon. 1993. New aromatic lemon basil
germplasm. p. 632-639. In: J. Janick and J.E. Simon (eds.), New crops. Wiley,
New York.
- Nadkarni, G.B. and V.A. Patwardhan. 1952. Fatty oil from the seeds of Ocimum
sanctum Linn. (Tulsi). Current Sci. 21:68-69.
- Patterson, H.B.W. 1989. Handling and storage of oilseeds, oils, fats and meal.
p. 112-113. Elsevier Applied Science, London.
- Pelick, N. and V. Mahadvan. 1975. Lipid derivatives and gas liquid
chromatography. p. 27-29. In: E.G. Perkins (ed.), Analysis of lipids and
lipoproteins. Am. Oil Chem. Soc., Champaign, IL.
- Simon, J.E., A.F. Chadwick, and L.E. Craker. 1984. Herbs: An indexed
bibliography 1971-1980; the Scientific literature on selected herbs, and
aromatic and medicinal plants of the temperate zone. Archon Books, Hamden,
CT.
*Journal Paper No. 14,984, Purdue University Agricultural Research Program,
Purdue University, West Lafayette, IN. This work was supported in part by the
Center for New Crops and Plant Products and a postdoctoral fellowship (NSERC of
Canada) to the senior author, which we gratefully acknowledge. Thanks are due
to E. Tousignant (Food Science Department, Laval University, Canada) for help
in glyceride analysis.
Table 1. Analytical values, glyceride content and fatty acid
composition of oil from seeds of different Ocimum chemotypes compared to linseedz.
|
| Species and chemotype |
| O. basilicum | O. canum | O. gratissimum | O. sanctum | Linum
usitatissimum |
| Variable | Citral | Linalool | Methyl chavicol | Methyl cinnamate | Camphor | Geraniol | Eugenol | Linseedw |
| Oil content (% w/w)y | 20 | 26 | 21 | 24 | 18 | 20 | 22 | 32-43 |
| Refractive index (nD20) | 1.481 | 1.480 | 1.479 | 1.479 | 1.472 | 1.460 | 1.477 | 1.477-1.482 |
| Saponification value | 199 | 200 | 200 | 200 | -- | 194 | 191 | 192 |
| Iodine value | 198 | 198 | 184 | 190 | 200 | 178 | 172 | 180 |
| Class (%) |
| Monoacyglycerols | 2 | 1 | 1 | 3 | 1 | 1 | 3 |
| Diacylglycerols | 2 | 1 | 1 | 2 | 2 | 1 | 3 |
| Triacylglycerols | 96 | 98 | 98 | 95 | 97 | 98 | 94 |
| Carbon number (%)x |
| 50 | 2 | 1 | 1 | 1 | 1 | 3 | 3 |
| 52 | 16 | 18 | 20 | 20 | 15 | 23 | 27 |
| 54 | 82 | 81 | 78 | 78 | 84 | 74 | 70 |
| Composition (mol%) |
| Palmitic (16:0) | 6.8 | 7.4 | 8.8 | 7.8 | 6.1 | 10.0 | 11.0 | 6 |
| Stearic (18:0) | 2.2 | 2.0 | 2.8 | 2.4 | 2.3 | 2.1 | 4.0 | 4 |
| Palmitoletic (16:1) | 0.3 | 0.2 | 0.2 | 0.2 | 0.2 | 0.3 | 0.2 | -- |
| Oleic (18:1) | 9.7 | 8.7 | 9.5 | 11.6 | 8.5 | 8.6 | 13.3 | 22 |
| Linoleic (18:2) | 18.3 | 21.7 | 21.3 | 20.6 | 17.8 | 31.3 | 26.8 | 16 |
| alpha-Linolenic (alpha-18:3) | 62.5 | 60.0 | 57.4 | 57.4 | 64.8 | 47.4 | 43.8 | 52 |
| gamma-Linolenic (gamma-18:3) | 0.3 | 0.1 | 0.2 | 0.3 | 0.3 | 0.2 | trace | -- |
| Arachidic (20:0) | 0.2 | trace | trace | trace | 0.2 | 0.2 | 0.2 | -- |
| Eicosenoic (20:1) | tracev | trace | trace | trace | trace | trace | trace | -- |
zModified from Angers et al. 1996. Data based on four
replications.
yBased on seed dry weight.
xCarbon number is relative to triacylglycerols.
wAnalytical and glyceride value from Bernardini (1985); fatty acid
composition from Patterson (1989).
vTrace values are lower than 0.1%.
Table 2. Analytical values and fatty acid composition of basil seed oil
reported in the literature.
|
| Species |
| Variable | O. basilicum | O. canum | O. kilimand-
scharicum | O. kilimand-
scharicum | O. pilosum | O. sanctum | O. viride |
| Oil content (% w/w)z | 24 | 10 | 13 | 16 | 17 | 18 | 10 |
| Refractive index (nD) | 1.47440 | 1.47140 | 1.48525 | 1.47740 | 1.47532 | 1.47930 | 1.48120 |
| Saponification value | 188 | 195 | -- | 193 | 187 | 182 | -- |
| Iodine value | 191 | 180 | 193 | 196 | 173 | 173 | 169 |
| Composition (mol%) |
| Palmitic (16:0) | }8y | 7.0 | 8.2 | }8y | 3.3 | 6.9 | 8.7 |
| Stearic (18:0) | | 0.2 | -- | | 6.4 | 2.1 | 2.7 |
| Oleic (18:1) | 15 | 11.1 | 5.3 | 17 | 15.4 | 9.0 | 14.3 |
| Linoleic (18:2) | 22 | 60.4 | 16.2 | 14 | 56.3 | 66.1 | 32.5 |
| alpha-Linolenic (alpha-18:3) | 50 | 21.3 | 65.0 | 61 | 18.5 | 15.7 | 39.2 |
| gamma-Linolenic (gamma-18:3) | -- | -- | -- | -- | -- | | -- |
| Arachidic (20:0) | -- | -- | 5.3 | -- | -- | -- | 2.6 |
| Eicosenoic (20:1) | -- | -- | -- | -- | -- | -- | -- |
| References | Earle et al. 1960 | Patwardan 1930 | Barker et al. 1950 | Henry and Grindley 1944 | Khan et al. 1961 | Nadkarni and Patwardhan 1952 | Barker et al. 1950 |
zBased on seed dry weight.
yValues for saturated fatty acids.
Last update July 1, 1997
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