Yam is an ambiguous name for several species of plants belonging to the genus Dioscorea of the Dioscoreaceae family cultivated in all tropical regions of the globe for food for their starch-rich tubers. The term designates both the tuber itself and the root bunch.
The term yam comes from the African root nyam which means to eat. The term yam only designates species whose tubers are edible. So when the species is poisonous, it is not designated by this term.
Two species of yams come from Southeast Asia, two from Africa and one from South America. Yam has never found its place in South America as sweet potatoes, potatoes and cassava are both native to this continent.
The species present in Africa were domesticated on this continent more than 6,000 years before our era. The yam would have arrived on our archipelago around the end of the 16th century in the boats transporting the slaves. Yam was also an integral part of their diet and was cultivated in the vegetable gardens provided for the crops dedicated to their food.
- Dioscorea alata: Plimbite, Belep, Pacala, Boutou, etc ...
- Dioscorea cayenensis: Portuguese, igname poule, yellow yam ...
- Dioscorea trifida: White or purple cousse couche.
They are climbing, twining plants, diodic remembers. The leaves are petiolate, heart-shaped, depending on the alternate or opposite species. In their armpits develop bulbils which can be used for the multiplication of the plant and sometimes consumable.
Tubers of variable shape are ovoid to oblong, sometimes flattened or shaped like an elongated club. They can be up to 1 meter in length and their weight generally from 3 to 5 kg can go up to 15 kg. The skin can be yellow, white or darker like brown or even black.
The flesh is usually white but can also be yellow.
In women, it is known that the daily consumption of yam lowers total blood cholesterol.
It also helps reduce blood pressure. Thanks to its antioxidant properties, yam acts on the brains of mice and improves their learning and memory skills.
It also helps reduce diabetes with better control of glucose and insulin levels.
It would also protect the liver and kidneys against damage caused by high doses of acetaminophen or alcohol.
Yam can also be used against the symptoms of menopause in animals. It has not been possible to verify this for humans and therefore cannot be recommended against hot flashes.
If in the past, it was mostly eaten after being boiled for several minutes in water, several recipes with yam as the main element have improved the way of perceiving it, which was only a simple element of the food of the slaves. This tuber was not present on the tables of the colonists who preferred to bring potatoes from Europe.
However, over time, the yam went from the tuber of the “poor” to an element valued in particular by the way of cooking it which was no more than a simple boiled yam. This is how he integrated the meals for Christmas and New Year's Day.
Today we eat yam gratin and in many other ways. It is part of what is locally called Légjim-Péi (local vegetables) like dasheen, vegetable-type bananas (green plantain banana and plantain), breadfruit or sweet potatoes.
Yam is produced in Martinique in large quantities to feed the local population. It is also imported to the metropolis but not in large quantities.