Sapotaceae are, in general, plants from the tropical regions.
Some are useful species :
- Sapote and sapodilla (genus Pouteria and Sapota (or Achras)), two fruits typical of tropical America and the Caribbean.
- The West Indian caimite (genus Chrysophyllum), small astringent fruit, stomachic and antidiabetic.
- In Africa, two sapotaceae, the shea tree and the argan tree are particularly important trees.
Both protect the soil from erosion and desertification and provide oleaginous fruits at the base of a small local industry (shea butter and argan oil).
The argan tree, Argania spinosa, is mainly found in southwestern Morocco, it is a surviving species of a time when this part of the world was much more humid.
The argan forest covers about 800 000 hectares in the Atlantic part of the Rif and in the plain of Souss.
ARGAN tree, with its highly developed root system associated with mycorrhizae, is able to survive in conditions of chronic drought and on poor, stony, often uncultivable soils.
For the Moroccan agronomists the argan tree is irreplaceable to fight against the soil degradation and the progressive desertification of the south of Morocco.
Unfortunately the argan tree is inexorably destroyed by humans: uncontrolled cutting to make charcoal or firewood, deforestation and grubbing to develop industrial crops, overgrazing by herds of goats that climb in the trees to eat leaves and fruits.
The argan tree is a very thorny tree, with often a twisted trunk, its light green foliage is abundant but falls in times of serious drought, its fruits, green then brown look like small olives.
The fruit contains a hard, light brown core, which contains several flattened almonds.
CHEMICAL COMPOSITION AND PROPERTIES
The argan leaves are rich in phenolic compounds, flavonoids, tannins with anti-inflammatory properties and scavengers of free radicals.
The leaves contain very little essential oil (0.03 to 0.05%). -
All other parts of the tree, including fruits, contain saponins (saponosides), which have recently been extensively studied by a Franco-Moroccan team.
Some of these saponins have been shown to be:
- antifungals at concentrations between 12.5 and 50 micrograms per ml of culture medium,
- molluscicides against Biomphalaria glabrata,
- antalgic and anti-inflammatory probably by altering or inhibiting the release of cytokines and leukotrienes that are primarily responsible for the inflammatory response and accompanying pain.
The acute toxicity of each type of saponin has not been determined, but overall, in rats or mice, the oral LD50 would be 1.3 g / kg.
Chronic toxicity: 200 to 300 mg / kg and per day, for 3 months, cause disorders of blood glucose and disruption of renal function.
The argan tree is best known for the argan oil extracted from the core of its fruit. The almonds contains about 50% fat, extractable by pressure (sometimes after light roasting in the traditional method ).
Simplified composition of argan oil, according to the Targanine cooperative website (targanine.com), in comparison with olive oil:
- palmitic acid 12 to 13% (7.5 to 20% olive oil),
- stearic acid 5 to 7% (olive oil 1 to 3%),
- 43 to 49% oleic acid (56 to 85% olive oil),
- linoleic acid 29 to 36% (olive oil 3.5 to 20%)
0.5 to 1% unsaponifiable (120 to 130 mg of sterols, 60 to 90 mg of tocopherols per 100 g of oil, triterpene alcohols 130 to 180 mg per 100 g of oil)
Argan oil does not contain saponins but the extraction cake contains about 0.5%.
Saponins of the argan oil extraction cake have interesting properties from a cosmetological point of view: antioxidant, protection against ultraviolet B, anti-acne.
The argan tree is a tree with multiple uses :
- Its wood is of good quality and resistant (partly thanks to the saponins that it contains (6%)),
- leaves and fruits of the argan is a good food for goats, sheep and camels,
- the fruit kernel provides argan oil, food grade and cosmetic,
- the argan oil extraction cake is suitable as a feed for cattle.
Argan oil is traditionally extracted after lightly roasting the almonds, it then has a nutty taste and an amber color.
Because of its fatty acid composition, argan oil is a high-quality dietary oil, which now finds its place in international fine dining.
Argan oil, extra virgin, extracted cold (without kernel roasting) is a skin protector, which softens the skin, prevents drying of the skin.
The content of vitamin E (tocopherol) of argan oil can be used to better fight against free radicals, which are responsible for the aging of the epidermis.
For the past ten years, Moroccan women (mainly Berbers) have joined forces in cooperatives (Targanine cooperatives) to extract and market argan oil in a community fashion. It is a socio-economic success; women share the money equitably, thus freeing themselves from the oppressive tutelage of their husbands.
The Moroccan authorities, including the king, are encouraging the action of these Berber women by encouraging the creation of new cooperatives and argan oil extraction units.
Food grade or cosmetic grade argan oil is readily available on the market. Moroccan cooperatives also directly sell this argan oil and products that contain it.
There are many cosmetic preparations containing argan oil (protection of the skin, skin care in general and more particularly for dry and damaged skin, moisturizing creams).
The saponins of the argan tree are not yet, to my knowledge, used in phytomedicines.
ARGAN TREES MEDICINAL and USEFUL
The argan tree of Morocco is a tree with many uses.
it is a tree endemic to the arid zones of southwestern Morocco.
Its foliage and fruits are used as fodder for goats and sheep.
The fruit almonds contain a dietetic and cosmetic quality oil, which is extracted and marketed in women's cooperatives.
Almost all parts of the argan tree contain saponins with interesting pharmacological properties.
Copyright 2019 : Dr Jean-Michel Hurtel