OILS USED IN DIETETICS, COSMETICS, AND LIPOCHEMISTRY
Some plant oils are used extensively in nutrition, cosmetics and
lipochemistry:
Black-currant
(Ribes nigrum, Saxifragacae). Frequently found in Europe and Asia. The
oil, rich in
g-linolenic acid, is used in oral and parenteral nutrition,
cosmetics and pharmacy (Patents by Nestlé SA). The composition of regioisomers
of triacylglycerols of two currant oils was determined (Kallio H et al., Eur
J Lipid Sci Technol 2005, 107, 101). It was shown that the preferential
order of fatty acid to be in the sn-2 position was typically
18:1>18:2>18:4>18:3. If only 2.4% of the species contained three
Avocado pear
(Persea gratissima, Lauracae). The plant originated from America. It is
mainly grown in USA, Mexico and Asia. Oil
content of the fruit mesocarp: 5-30% (according to the variety and location). The oil is used
in pharmacy and cosmetics, it is known to contain a high proportion of
unsaponifiable substances (1-2%) with a high percentage of sterols (20-70% of
the total), hydrocarbons (5-20%) and triterpen alcohols (6-40%).
The oil is mainly composed of oleic acid (67-72%), palmitic acid (13-17%), and
linoleic acid (10-12%). The main triglyceride species are OOP (20%), OOO (15%),
LOO (10%) and LOS 9%).
A chemical characterization of the oils from the pulp and seeds of avocado
fruits may be found in the work by Bora PS et al. (Grasas y Aceites 2001, 52,
171). Data on glycolipids and phospholipids molecular species in the pulp
and the almond of avocado have been reported (Pacetti
D et al., J Chromatogr A 2007, 1150, 241).
Borage
(Borago officinalis, Boraginacae). Oil is rich in
g-linolenic acid (18-25%).
Cultivated in west mediterranean regions. Oil content: 13-33%. A typical fatty
acid composition is : linoleic (35.4%), oleic (22.9%), g-linolenic
(18.4%), and palmitic (11%) acids.
The oil is used
in pharmacy and cosmetic.
Cacao (Theobroma cacao, Sterculiacae). The plant originated from Amazonia but is cultivated in Africa and Brazil.
Fat content of the roasted kernels: 50-60%.
The roasted bean is ground to give cacao mass from which much of the cacao
butter is extracted by pressing. Its melting point is about 33°C and is
composed of 24-29% palmitic acid, 34-36% stearic acid,30-40% oleic acid and 2.4%
linoleic acid. The main triglyceride species are SOP (36.4%), SOS (23.5%), and
POP (16.6%) (Lisa M et al., J Chromatogr A 2008, 1198-1199, 115).
Cacao butter is used in human nutrition (manufacture of chocolate), pharmacy (suppositories)
and cosmetics. The world
production of cacao beans was about 3 million tons in 1999.
Castor bean
(Ricinus communis, Euphorbiacae). Castor was used in Egypt as a lamp oil
about 6000 years ago. It is indigenous to eastern Africa, and most probably
originated in Ethiopia.
Oil content: about 50%.
The oil is composed of more than 94% triacylglycerols, the remaining being
monoglycerides (3.4%), and phospholipids (0.6%). Castor oil is the only
commercial source of ricinoleate. Its specific fatty acid composition is : 1% 18:0, 3% 18:1, 3% 18:2, about 90%
hydroxylated 18:1 (ricinoleic acid) and 1% dihydroxylated 18:2.
About 70% of castor oil is tri-ricinolein (tri-ricinoleoylglycerol) (Lin JT et
al., J Liq Chromatogr Relat Technol 2003, 26, 773). Moreover, 0.5% of the
lipid content is composed of a tetra-acylglycerol containing four ricinoleic acid
molecules ((12-ricinoleoylricinoleoyl) di-ricinoleoylglycerol), 95% of the
12-ricinoleoylricinoleoyl chain being identified at the sn-2 position of
the glycerol backbone (Lin JT et al., J Agric Food Chem 2006, 54, 3498).
Castor
oil and many of its derivatives are stabilized by the hydroxyl group, which
is beta to the double bond. This hydroxyl group protects the double bond by
preventing the formation of peroxides.
As a result, castor oil is
approximately four times more stable than olive oil. The oil is more dense and
viscous than most other vegetable oils and completely miscible with ethanol.
After suitable pretreatment, the
oil is poorly used in medicine but largely used in lipochemistry (drying oils,
paints, ink, soaps, lubricants, varnish), cosmetic (non-comedogens
and emollients).
Chemical industry used castor oil after oxidation, alkoxylation, dehydration,
hydrogenation and sulfonation.
The
world production of castor beans was about 0.5 million tons in 2004-05, India
producing about 70% of the total, the remaining being produced in China, Brazil,
Russia, Thailand and some African countries.
Evening
primrose (Oenothera
biennis, Onagracae). Oil well known for its high content in g-linolenic
acid. Numerous varieties are cultivated in America and in Europe. Oil content:
12-30%. The oil is used in pharmacy and cosmetics.
Kukui oil
(Aleurites moluccana, Euphorbiacae). The
tree which gives the nuts is the official symbol of the "Aha Kupuna,
the Council of Elders of the Nation of Hawaii". The seeds contain a high
amount of fluid oil which has many uses, among them lighting (the tree is also
named "candlenut tree"), in medicine (purgative, psoriasis, eczema and
other dry skin problems), lipochemistry (varnish) and in cosmetics. The oil is said to
contain 25.6% linolenic acid, 39.4% linoleic acid, 25% oleic acid, 9% palmitic
acid. The main triglyceride species are OLLn (13.6%), LLLn (11%), OLL
(10.2%), LLL (7.5%), LnLLn (6.6%) (Lisa M et al., J Chromatogr A 2008,
1198-1199, 115).
Wheat germ
(Triticum vulgare, Graminae). The oil is used in dietetic and cosmetic. A
typical fatty acid composition is linoleic (54.8%), oleic (17.8%), palmitic
(16.5%) and linolenic (8%) acids. The main triglyceride species are LLP (19.8%),
LLL (15.3%),OLL (13.5%), and LLLn (6.5%) (Lisa M et al., J Chromatogr A 2008,
1198-1199, 115).
To learn more on the
fatty acid composition of some of these oils and fats
