The jojoba shrub or bush belongs to the genus Simmondsia and to the family of Simmondsiaceae. It is an evergreen plant which grows in warm areas up to a height between 0.5 and 2 meters. Thanks to its deep roots (up to 3 meters deep) and its hairy leaves (sclerophyllous) the jojoba shrub has a good adaptability in dry regions. The leaves are oval shaped, alternate and dark green or yellowish (Albino species).
The bush has elongated to oval fruits with one to three seeds and can vary in size depending on their geographical location. The seed is released only after complete maturity and has a wax content up to 60 % of its dead weight.
Plants need little water in their natural habitat but Irrigation will significantly increase the yield if grown on plantations. As the jojoba shrub should not be watered during fruit development, it can be grown with other citrus fruits (similar cultivation). Another characteristic is the high salt tolerance of the jojoba plant: This enables re-cultivation of barren saline grounds.
2. Origin/flowering time/harvest
The Jojoba bush prefers a warm and dry climate like all sclerophyllous plants. Besides its natural spread in Mexico and the US, Jojoba is also cultivated in Israel, Argentina, Peru, India, Kenya and Australia.
On plantations the bushes are grown in the form of hedges with a ratio of at least 5 (female) to 1 (male) in order to guarantee sufficient pollination. Depending on the status of cultivation a first yield can be expected after 3 to 5 years (optimum yield after 7 to 12 years).
After a normal flowering time during spring the mechanical harvest takes place from August to October.
Common procedures to obtain the wax are cold pressing (by grinding the ripe dry seeds) and extraction.
The wax esters, a compound of fatty acid and fatty alcohol, give the oil its typical chemical characteristics. The long carbon chains (38-44 carbon atoms) on each side at the end of the ester are characteristic for this plant species.
The oil has a high melting point starting at 7 degrees Celsius and a resistance towards chemical/enzymatic reduction (esters are hard to split). As a result, jojoba oil turns rancid very slowly and can last up to 25 years if stored correctly.
An enzymatic reduction cannot take place in the digestive tract why Jojoba oil is sometimes promoted for weight reducing diets.
However, oral application is not recommended, as several studies have shown pathological changes in blood count and internal organs. Although an improvement of the skin is often recognized, endogenous parameters are not considered in most studies.
In pharmacy the oil is used to mask oxidation-sensitive substances, weight reducing diets and as an appetite suppressant. The chemical inertia of the ester is used here. Furthermore Jojoba oil supports the healing process with inflammations (i.e. sunburn).
Jojoba oil is quickly absorbed into the skin, leaving no greasy film and giving the skin a moisturizing effect. The skin becomes soft and smooth while additionally strengthening the connective tissue. Further advantage: The oil is anti-allergenic and can be used for all skin types.
The cosmetics industry takes advantage of these effects and uses the oil in many body care products, such as shampoos or lipsticks. In addition the oil has a natural sun protection factor of about 4 which makes it suitable as an additive or even base for sun creams.
In the industry an extended product range is achieved by further processing and refining steps. Applications as high-quality lubricants, polishing waxes and even diesel substitutes with specific properties can be obtained in this way.
5. Further properties/facts
In addition to the above mentioned esters, jojoba oil also contains sterols, tocopherol, amino acids, minerals and provitamin A. The total tocopherol content differs especially between cold-pressed and refined oil: in cold-pressed oil alpha tocopherol (vitamin E) is dominant and in refined oil beta tocopherol is dominant.