In the popular drama "The Legend of Zhen Huan", in order to frame Zhen Huan , she fed Princess Wen Yi, who was still in her cradle, Princess Wen Yi, , made of cassava flour , which eventually led to Princess Wen Yi constantly vomiting milk. The audience also learned the hard-core knowledge point of "cassava is poisonous" from this palace drama.
bitter cassava roots, stems and leaves contain a substance called " flax seed kelp ". After eating fresh bitter cassava, flax seed kelp kelp will enter the stomach, and fusion with gastric acid will cause a decomposition reaction to produce hydrocyanic acid .
Hydrocyanic acid, also known as hydrogen oxide, is highly toxic. According to clinical trials, if a person eats 100-300 grams of bitter cassava raw, it will cause poisoning, while a kilogram of bitter cassava is enough to poison an adult.
However, such plants that contain the risk of "poisoning people" have been planted in large quantities in Africa, and many African people even use them as staple food. Why are they not afraid of being poisoned?
Why did African people choose cassava as the main plant?
On this land of Africa, cassava, like rice and wheat in China, solves the problem of food and clothing for countless hungry people. It is one of the staple foods of African people and the most grown food crop in Africa.
But why is it cassava? What is the reason why African people ignore such great toxicity and choose to grow cassava as their staple food?
[Geographical reasons and objective reality]
Africa has high temperatures, and most areas have barren land, drought and rainy, and the conditions are harsh, so the most full-fill ordinary grain crops cannot grow well here.
Only drought-tolerant cassava grows "like a fish in water" in Africa. Cassava is not only drought-resistant and acid-resistant, but can even like the tropical climate very much. It can also resist barrenness and desertification. No matter how barren land is, it can grow well.
, and the cultivation method of cassava is very extensive and , and it does not need to be very refined. Just throw large pieces of cassava roots into the soil and bury them, without the need to breed seedlings and fertilize them specifically, and you don’t have to worry about pest bites. In autumn, you can harvest a large cluster of cassava.
cassava and are particularly prolific , which can be harvested all year round; the precipitated starch content is also extremely high, reaching 24%-32%, and up to 83%. It has the reputation of ", the king of starch ", and can bring users a strong sense of fullness.
Planting is cheap and the cultivation methods are simple. Growing cassava seems to be the most preferred thing Africa can do: it’s not that I don’t want to choose, but that I don’t have to choose. Adding together various advantages, cassava has become the first choice for food in African countries with shortage of food, low modernization of traditional agricultural technology, poor cultivation conditions, and a large population. Even if encountering natural disasters and man-made disasters, cassava with strong adaptability can ensure that African people have a good meal.
Especially in sub-Saharan Africa, where the most densely populated areas in Africa, almost every family is growing cassava. In Nigeria, which has more than 60 million hectares of arable land, 95% of the actual cultivated land is used to grow cassava. The cassava they grow is not only used for daily consumption, but also for export and retention.
In addition to Nigeria, African countries such as Democratic Republic of the Congo , Mozambique , Tanzania also mainly cultivate cassava, contracting 66% of the world's cassava production.
[Detoxication and cooking of cassava]
cassava is poisonous, this is the conclusion drawn by Africans after personal experiments and paying the price. So in Africa, people have a simple and useful way to get rid of the poison.
They usually remove the rhizomes and leaves of cassava, scrape the skin and soak it for a day or two before cooking it for a period of time, and only eat the cooked cassava pieces. This is because, compared with the -week skin of leaves, rhizomes and roots, the cassava blocks after cooking will lose some toxicity, which is safer.
Cassava has hundred ways to eat , which can be said to be the king of food.No matter whether you fry, cook, steam, roast, and bake, or ferment it into tapioca wine, it has a unique flavor. The most famous one is a food called "fu fu". It is made of steamed, grinded and mashed into a paste. You can eat the cassava balls directly, or you can fry the cassava balls again and eat it. With the unique dipping sauce, it is full and delicious.
In addition to being a staple food, Africans will also add cassava to corn paste or bread, which can not only increase the use of cassava, but also improve the taste of bread or corn paste.
[Economic benefits brought to Africa by cassava]
For African people, cassava is a real "savior" crop. It is not only an grain crop that ensures people's food and clothing, but also an cash crop that can bring business opportunities. In Africa, the yield per acre of cassava can reach 2 tons, and even the highest yield can reach 6 tons, and a piece of cassava is enough for a family to have a meal. So what can extra cassava be used for?
In , in the region of Africa or the country of planting, such as Nigeria, a cassava flour processing industry has been established. But because Nigeria's processing industry is not well developed, they can only finish high-quality cassava flour on a small scale and then use it to add it to food.
The Nigerian government has introduced a policy of "bread must contain at least 10% cassava flour", of course, not only bread, but also various other sweets. Such policies will help increase employment in Nigeria, promote the use of cassava flour and the cultivation of cassava, increase the income of growers and workers in related industries, and realize the virtuous economic cycle of .
. In terms of exporting abroad, the Nigerian government is "crazy" to increase the technology to increase the planting volume and quality of cassava, improve processing technology, and seek more foreign export orders for with . According to data from third-party survey agencies, the export products of Nigeria starch plants are aimed at well-known companies such as food manufacturer Nestle and candy manufacturer Cadbury .
Moreover, as people's discoveries in the field of using cassava starch broaden, the export countries of African cassava are also increasing. Since my country imported 1 million tons of dry cassava chips to Nigeria in 2005, this value is increasing year by year.
As a major importer of cassava, why does China not plant it independently?
is one of the six largest crops in the world. Cassava can not only be used as food, but also as an industrial product .
The starch it precipitates is an important raw material for ethanol , maltose , glucose , dextrin and other substances. Even in papermaking, starch can be prepared as printing pulp, used for sizing and glue; in tablet making, it can be used as a diluent and disintegrant to make drug tablets; even in the oil drilling industry, tapioca starch can be used as pregelatinized starch and added to the drilling industry...
For Africa, where food and clothing are still a problem, the industrial use of tapioca starch is definitely not useful. However, for China, where industrial development is booming, starch is needed in every industry and every field. China has a huge gap in demand for cassava starch, so why not plant cassava on a large scale?
[Growing Cost]
Cassava was introduced to China in the 1920s, and then it was quickly planted in Hainan, Yunnan, Jiangxi, Fujian and Guangdong and Guangxi.
can be used to develop industries in various industries, and the gap in demand for starch is expanding. The more cassava is grown locally, the greater the labor and cost loss caused.
Although cassava is high in yield and can be harvested in all seasons, it still requires the necessary cost to plant high-quality crops. The current market price of raw cassava in China is only 500 yuan per ton, and the purchase price is only 25 cents per kilogram. "Rice is cheap and harms the people". Such a price may not even be able to recover the cost for cassava growers, which is a real loss.
Plus in Guangxi, which is suitable for growing cassava, young laborers are leaving the countryside and land to work and make a living in big cities. They are no longer trapped on the land to grow cassava, and the remaining elderly, weak, sick and disabled cannot bear the heavy planting work. As a result, my country's cassava planting area has shrunk, and the local cassava production has dropped significantly, from 681,900 tons in 2012 to 170,100 tons in 2019, becoming a major importer of cassava.
[Some money is still suitable for others to earn]
The largest producer of cassava in the world is Nigeria. China's main importers include Vietnam, Cambodia , Thailand, Laos and Indonesia . The common characteristics of these countries are: cheap land and cheap manpower. They opened up China's cassava import path with much lower costs than the local cultivation.
Take Thailand as an example. There is almost 2 million people growing cassava. With it as the main source of income, it can produce 16 to 19 million tons of fresh cassava each year. Half of them are used for export in the form of cassava chips and cassava grains, and the remaining half is exported in the form of cassava flour. Not only is it a good exporter, it also has a reputation for its excellent variety, advanced technology, selection and quality.
. With the move of "low price tags" in Southeast Asian countries, China faces both huge contradictions between internal demand and supply, and cruel external competition, so it directly gave up the track of cassava planting.
"We eliminated this gradually outdated agricultural product, chose to reach cooperation with other countries at preferential prices, contribute to the development of their industry, and support our people to move towards a more prosperous future."
This is the benefit of the people-oriented development trend of the industry.
A small piece of cassava witnesses the lives of the people on the continent, both the past and the future. Cassava is poisonous, but it still needs to be grown in large quantities in Africa because they have no choice for food and clothing.
We hope that the cultivation and production of cassava can be for the development of industry, for the existence of small snacks such as "pearls", mochi, etc., rather than bearing the attributes of "end of the world's relief food", and we encourage the world.
Reference:
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- Dai Yin, Luo Chengwen, Chen Junshi, etc.: Research on the residual toxin standards of cyanide in cassava, Compilation of paper abstracts of Chinese Physiological Association Academic Conference (nutrition)
- Compilation of paper abstracts of Chinese Physiological Association Academic Conference (nutrition), Compilation of paper abstracts of Chinese Physiological Association Academic Conference Academic Association Academic Association Academic Association (nutrition)
- Zhu Xudong: China imported the first alcohol raw material dried cassava from Africa, China Chemical Industry Journal
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