Food that should be cooked

 Translated and edited by: Joe Hing kwok Chu

Soy and soy milk:

Raw soybeans contain saponin, which is toxic. After boiling saponin is destroyed. Consuming raw soy milk can cause food poisoning.

Beware that when soy milk is heated to about 80 ℃, the saponin will expand and create bubbles, creating a illusion that it is boiling, a "false boiling" phenomenon. At this temperature the soy milk toxic saponin is not completely destroyed. Drinking it can cause poisoning, usually after half hour to 1 hours the symptoms of gastroenteritis will occur.

Detoxifying soy and soy milk:

Boil the soy milk till the bubbles are dissipated then boil further for about 10 more minutes. Usually when the soy beans are cooked till soft, it is safe.

Green beans:
Raw green beans contain saponin which is toxic. It can strongly stimulate the digestive tract. Green beans also contain phytohemagglutinin (a lectin) , with blood clotting effect.

Furthermore beans also contain nitrite and trypsin and can stimulate the stomach, and can also cause food poisoning, gastroenteritis symptoms.

Detoxifying green beans:

Usually cooking until soft to eat, it will be safe.

Cassava:

 The cassava roots and leaves contain two cyanogenic glucosides:

1. linamarin

2. lotaustralin

Ater consuming the cassava roots, the cyanogenic glucosides after hydrolizing by the stomach acid they become the free form of hydrogen cyanide and become highly toxic.

The amounts of these potentially toxic compounds vary considerably, according to growing conditions and varieties. "Sweet" varieties (Manihot esculenta Crantz) usually have such small amounts as to be innocuous, whereas bitter varieties (Manihot utilissima Pohl.) have sufficiently high levels to require processing to remove most of the toxins.


Detoxifying cassava
Boiling and drying are sufficient to make low-cyanogen variety (Manihot esculenta Crantz) safe for consumption. For  the bitter variety (Manihot utilissima Pohl.) of higher toxicity more rigorous procedures such as grating, fermenting, and sun-drying, are necessary to effectively to  remove the cyanogens.

Fava beans (faba beans, broad beans)

Fava beans contain vetch alkali glycosides. Consuming this substance, can cause acute hemolytic anemia (favism). Eating fava beans during spring and summer, if not cooked properly, can cause poisoning phenomenon. Usually after eating raw fava beans symptoms can occur in 4 to 24 hours.

Detoxifying fava beans: cooking will remove the toxin.

Jin zhen cai 金針菜 (flowers of easter lily plant)

Huang hua cai 黃花菜 is also known as jin zhen cai 金針菜. It is the flowers of easter lily plant. It is one of the favorite Chinese dishes. But the raw lilies contain colchicine. After consuming raw lilies, it will be oxidized in the body tissues, generating two colchicine. The two Colchicine is a highly toxic substance that can poison the human gastrointestinal tract, urinary system, a serious threat to health. An adult if an ingestion of 50 to 100 grams of fresh lily can cause poisoning.
Although colchicine poisoning is relatively uncommon, it is imperative to recognize its features as it is associated with a high mortality rate when missed.[1]
 

[1] Clin Toxicol (Phila). 2010 Jun;48(5):407-14. doi: 10.3109/15563650.2010.495348.

生豆漿

　　毒素：皂素

　　致使機理：

　　生大豆含所皂素是有毒成份。煮沸後皂素被破壞。如果豆漿未煮熟時就食用，可引起食物中毒。特別是將豆漿加熱至80℃左右時，皂素受熱膨脹，泡沫上浮，形成“假沸”現象，其實此時存在於豆漿中的皂素等有毒害成份並沒有完全破壞，如果飲用這種豆漿即會引起中毒，通常在食用0.5～1小時後即可發病，主要出現胃腸炎症狀。

　　解毒方法：

　　為了防止飲用生豆漿中毒，在煮豆漿時，出現“假沸”後還應繼續加熱至100℃。煮熟的豆漿沒有泡沫，而且消失的泡沫也表明皂素等有毒成份受到破壞，然後再用小火煮10分鐘左右，這樣即可達到安全食用的目的。

　　四季豆

　　毒素：皂素

　　致命機理：

　　如果四季豆未煮熟，豆中的皂素會強烈刺激消化道，而且豆中含有凝血素，具有凝血作用。

　　此外四季豆中還含有亞硝酸鹽和胰蛋白酶，可刺激人體的腸胃，使人食物中毒，出現胃腸炎症狀。

　　解毒方法：

　　為了防止出現四季豆中毒，一定要將四季豆煮透、煮熟。

　　木薯

　　毒素：亞麻仁苦甙, 百脈根甙

　　致命機理：

　　盡管木薯的塊根富含澱粉，但其全株各部位，包括根、莖、葉都含有毒物質，而且新鮮塊根毒性較大。因此，在食用木薯塊根時一定要注意。木薯含有的有毒物質為亞麻仁苦甙，如果攝入生的或未煮熟的木薯或喝其湯，都有可能引起中毒。其原因為亞麻仁苦甙或亞麻仁苦甙酶經胃酸水解後產生游離的氫氰酸，從而使人體中毒。

　　一個人如果食用150～300克生木薯即可引起中毒，甚至死亡。

　　解毒方法：

　　要防止木薯中毒，可在食用木薯前去皮，用清水浸薯肉，使氰甙溶解。一般泡6天左右就可去除70%的氰甙，再加熱煮熟，即可食用。

　　蠶豆

　　致命毒素：巢菜鹼甙

　　致命機理：

　　蠶豆種子中含有巢菜鹼甙，人食用這種物質後，可引起急性溶血性貧血(蠶豆黃病)。春夏兩季吃青蠶豆時，如果烹制不當，常會使人發生中毒現象。而且一般在吃生蠶豆後4～24小時後發病。

　　解毒方法：

　　為了防止出現蠶豆中毒，最好不要吃新鮮的嫩蠶豆，而且一定要煮熟後再食用。

　　黃花菜

　　致命毒素：秋水仙鹼

　　致命機理：

　　黃花菜又被稱為金針菜，是人們喜愛的菜肴之一。但黃花菜中含有秋水仙鹼，如果人體攝入秋水仙鹼後，會在人體組織內被氧化，生成二秋水仙鹼。而二秋水仙鹼是一種劇毒物質，可毒害人體胃腸道、泌尿系統，嚴重威脅健康。一個成年人如果一次食入鮮黃花菜50～100克即可引起中毒。

　　解毒方法：

　　要防止出現鮮黃花菜中毒，可將鮮黃花菜在沸水中稍煮片刻，再用清水浸泡，就可將大部份水溶性秋水仙鹼去除。也可將鮮黃花菜煮熟、煮透，再烹調食用。

　　薺菜

　　致命毒素：亞硝酸鹽

　　致命機理：

　　青菜中的薺菜、灰菜等野菜都含有大量亞硝酸鹽。如果人體攝入過量亞硝酸鹽，可將人體內正常的血紅蛋白氧化成高鐵血紅蛋白，此外，亞硝酸鹽還可阻止氧合血紅蛋白釋放氧，從而引起組織機體缺氧，使人發生中毒。

　　解毒方法：

　　那麼，怎樣才能預防亞硝酸鹽中毒呢？其實很簡單，一定要讓家人食用新鮮菜，煮熟的菜不宜久悶存放，腌菜應在腌制一個月以後洗滌後才可食用。

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　　發芽馬鈴薯

　　致命毒素：茄鹼

　　致命機理：

　　馬鈴薯是家庭餐桌上經常食用的蔬菜之一，但它含有毒成份茄鹼(馬鈴薯毒素、龍葵甙)，馬鈴薯全株都含有這種毒素，不過，各部位含量不同，成熟馬鈴薯含量較少，一般不引起中毒，而馬鈴薯的芽、花、葉及塊莖的外層皮中卻含有較高的茄鹼，馬鈴薯嫩芽部位的毒素甚至比肉質部份高幾十倍至幾百倍。

　　未成熟的綠色馬鈴薯或因貯存不當而出現黑斑的馬鈴薯塊莖中，都含有極高的毒性物質。

　　解毒方法：

　　為了防止馬鈴薯中毒，我們可將馬鈴薯貯藏在干燥陰涼的地方，防止發芽。吃時，如果發現發芽或皮肉呈黑綠色時，最好不要食用。