OILS USED IN DIETETICS, COSMETICS, AND LIPOCHEMISTRY
Some plant oils are used extensively in nutrition, cosmetics and lipochemistry:
Avocado pear (Persea americana, Lauracae). The plant originated from America. It is mainly grown in USA, Mexico and Asia. Oil content of the fruit mesocarp: 8-22% (according to the variety and location). The world production of avocado oil is about 1,500 t. The oil is used in pharmacy and cosmetics, it is known to contain a high proportion of unsaponifiable substances (1-3 %) 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 (24 %), OOO (32 %), LOO (10 %) and LOP (10 %) (Jakab A et al., J Chromatogr A 2002, 976, 255).
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).
(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 NestlÃ© 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 a– or g-linolenic acids, about 18% contained two of these molecules. A typical fatty acid composition is : linoleic 38%, oleic 17.3%, linoleic 15.8%, g-linolenic 14%, and palmitic 9% acids. The main triglyceride species are OLL 6.7%, LLL 6.3%, LLLn 6.2%, OLLn 5.1%, LLP 5%, gLnLP 5%, OLgLn 4.8%, and LLgLn 4% (Lisa M et al., J Chromatogr A 2008, 1198-1199, 11).
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.
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 33Â°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). Both for cocoa and chocolates differences in fatty acid profile are observed and are mainly explained as an effect of the geographical origin, and not by processing conditions. For cocoa, differences in fatty acid profile are found in C12:0, C14:0, C16:0, C16:1, C17:0, C17:1 and C18:0 (Torres-Moreno M., et al., Food Chem 2015, 166, 125).
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.
The uncertainty in cocoa butter supply and the volatility of its price have forced producers to seek alternatives to replace cocoa butter. Thus many similar fats were used as confectionery fats such as lauric cocoa butter substitutes, non-lauric cocoa butter substitutes and cocoa butter equivalents. The last ones are closest to cocoa butter. The European Union requirements are : SOS > ou = to 65%, unsaturated FA at the position sn-2 > ou = to 85%, total unsaturated FA < or = to 45%. The use of specific lipases and various source oils enable a large-scale production of cocoa butter substitutes.
Castor bean (Ricinus communis, Euphorbiacae). Castor was used in Egypt as a lamp oil about 6000 years ago. Later, it was used as a cosmetic product and in medicine (laxative) in India and China. 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), cosmetics (non-comedogens and emollients) and food industry. 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 (18%), 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