In the 17th century, the Dutch painter Albert Eckhout created a vivid natural history painting of cassava, showing the appearance and ecological characteristics of cassava. This painting not only captures the beauty and uniqueness of cassava, but also implies the deadly secret hidden in it-its tuberous roots contain a large amount of cyanide, which is fatal if eaten raw. However, it is this plant, although full of dangers, that has become the staple food for more than 800 million people around the world. Its complexity and multiple identities make humans full of awe and dependence in their relationship with cassava.
Cassava natural history painting created by the Dutch painter Albert Eckhout in the 17th century
Cyanide is a substance with a slight bitter almond flavor (actually because bitter almonds contain cyanide), and only 50~200 mg is enough to kill an adult. For this reason, cyanide is a strictly controlled chemical.
But there is a plant whose tubers contain a large amount of cyanide, and a bite of it raw is enough to be fatal. However, it is the staple food for more than 800 million people, and is also the main raw material for many foods, even laundry detergent and cat litter. This is cassava (Manihot esculenta).
Cross section of cassava tuber
Cassava is a plant of the Euphorbiaceae family. There are two characteristics of the Euphorbiaceae family. One is that wounds on branches or stems and leaves are prone to oozing white juice; the other is that this plant family is famous for its "toxicity", such as rubber, castor, Chinese tallow tree, croton, etc. There is even a plant in this family that makes people terrified, the poisonous guava (Hippomane mancinella), which is one of the most toxic plants known to date.
Manchineel, also known as the poisonous guava, is a tree plant of the Euphorbiaceae family, mainly distributed in Florida, USA and Central and South America.
Cassava is rich in cyanogenic glycoside compounds and various alkaloids. If people accidentally eat fresh cassava tubers, these substances will come into contact with stomach acid to form highly toxic hydrocyanic acid. But cassava stores energy in the form of starch in the tubers, which makes humans look at it differently.
The taproot and main lateral roots of cassava will swell and grow, just like a wooden root with "radishes" growing under it.
Cassava originated in the southern edge of the Amazon Basin in South America. Indians had already started eating cassava at least four thousand years ago. Before Columbus arrived in America, cassava was already widely planted in America. With the great exchange of species between the New and Old Worlds, cassava was widely planted in Africa, Asia and Oceania after the 15th century.
Cassava not only has a high starch content, but is also drought-resistant, has a short growth period, is suitable for growing in various soils, and has a high yield. This allowed it to quickly adapt to the matching mechanism of the African region. Today, Nigeria has surpassed Brazil, the origin of cassava, to become the world's largest cassava producer.
Cassava farmland
The yield of cassava per mu can reach an astonishing 6 tons, and the energy generated per unit area of land by planting cassava is much higher than that of rice, corn and wheat. Therefore, it is a food crop that many developing countries rely on for survival. In addition, cassava starch can also be used to make feed, alcohol, glucose, plastic fiber, coatings, etc. Because its price is lower than other starches, although we rarely see fresh cassava tubers, cassava has already been present in all aspects of our lives.