2. Cassava starch is often used in food, such as pearls of milk tea.
3. The content of cyanide should be controlled when cassava is used to ferment alcohol to make liquor.
4. Cassava is the staple food in many developing countries.
5. Cassava also has many uses in animal husbandry and other industrial fields.
There used to be a saying on the Internet that the "pearls" of Q bombs in milk tea were made of plastic and could not be eaten.
This is obviously nonsense. Who can make plastic so delicious?
However, it seems reasonable to say that it is poisonous. After all, its raw material is a poisonous plant called cassava.
Is the "pearl" poisonous or not? Can you eat it often?
Cassava is a common tropical crop, and it is also called the three major potato crops in the world with potatoes and sweet potatoes.
It originated in South America, and now it is widely distributed all over the world, especially in Africa, Latin America and Southeast Asia. It is one of the staple foods of local people, some of which are directly cooked and eaten, and some are made into cakes and desserts.
Cassava and sweet potato are both swollen roots for human consumption, and the main ingredients are starch, and they look a bit like each other.
But they are actually completely different species, sweet potato is a herb, and cassava is a shrub.
Cassava has strong vitality and can grow in relatively poor soil, and its yield is very high, with an average of 4000 kg per mu, with the highest record exceeding 12000 kg.
At present, there are more than 800 million people eating cassava in the world, and the global annual output is about 300 million tons, of which more than half are produced in Africa.
It was introduced to China in11920s, and now it is mainly cultivated in Guangxi, Hainan, Guangdong, Yunnan and Fujian.
In addition, cassava roots, leaves and processing wastes can be used as animal feed, and cassava can also be used to produce chemical products such as resins, coatings, adhesives, films, enzyme preparations and medicines.
Cassava contains a substance called cyanoside, which produces bitter taste and is a "weapon" for plants to protect themselves. It is common in seeds and young leaves.
Cyanosides can be decomposed in the stomach and release highly toxic hydrocyanic acid. Eating too much may lead to poisoning or even death, and bitter almond poisoning is the reason.
(There is also a plot of cassava powder poisoning in Zhen Chuan, but the background of the story is that cassava has not been introduced into China during Yongzheng period.)
The roots, stems and leaves of cassava all contain cyanosides, but the fresh tubers are the most, and the content of cyanosides of different cassava varieties is very different.
There is a folk saying that cassava is divided into bitter cassava and sweet cassava, and sweet cassava is non-toxic.
In fact, this statement is not true. For example, there have been cases in which sweet cassava poisoning caused many deaths in the Philippines.
Therefore, no matter what variety, cassava needs to be peeled, rinsed, cooked thoroughly or reprocessed before eating to ensure safety.
Cassava starch content is high, accounting for 70-80% of dry weight. Besides being eaten directly, it can also be used in food industry.
For example, high value-added food raw materials such as fructose, glucose, edible alcohol and amino acid (monosodium glutamate) are produced by fermentation process, in which cyanide may exist in edible alcohol.
Some Chinese liquors are blended with cassava-fermented alcohol. In order to control the potential poisoning risk, China's national liquor standard (GB2757-20 12) stipulates that cyanide (calculated by hydrocyanic acid) should not exceed 8 mg per liter.
In addition, because the human body can metabolize cyanosides and there is no accumulation, as long as it is not ingested in large quantities in a short time, it will be fine.
Therefore, even if it occasionally exceeds the standard, the probability of cyanide poisoning caused by drinking is still very small (alcoholism is more likely).
The more important use of cassava is to extract cassava starch, and the processed cassava starch has almost no risk of poisoning.
Cassava starch can be processed into vermicelli, vermicelli, shrimp slices, biscuits, bread, beer and other foods, and the pearl of milk tea (also called rice noodles) and the dumpling skin of crystal shrimp dumplings are often made of it.
Therefore, it is okay to eat pearls in milk tea often, but it should be noted that milk tea is often high in energy, and getting fat is its biggest health risk.