Is fresh toon poisonous?

Toona sinensis is a wild plant rich in cellulose. Due to its special taste, many people pick fresh toona sinensis to eat during the blooming season. Especially in modern high-tech society, fresh wild vegetables are even more popular among people. Moreover, toon contains a large amount of protein, which can provide the human body with the energy necessary for survival. However, some people may experience adverse reactions after eating fresh toon. So, is fresh toon poisonous?

Toona sinensis is poisonous.

Toona sinensis contains nitrates and nitrites, the content of which is much higher than that of ordinary vegetables. The protein content in toona sinensis is higher than that of ordinary vegetables, and there is also the risk of producing carcinogenic nitrosamines. Therefore, eating toona sinensis poses a safety hazard.

So, how can we eat safe and nutritious toon? Here are a few principles to follow:

First, choose the tenderest toon sprouts. Studies have found that the content of nitrate and nitrite in toon from different regions, varieties and growth periods varies. The most important thing is that the nitrate content of toon is low in the early stage of germination. As the toon sprouts continue to grow, the nitrate content also increases. After mid-April, the nitrate content in toon sprouts in most areas exceeded the standards of the World Health Organization and the Food and Agriculture Organization of the United Nations. In other words, the tenderer the toon sprouts are, the less nitrate they contain, and the less nitrite will be produced during future storage.

Second, choose the freshest toon sprouts. The test also showed that after mid-April, although the nitrate content in toon shoots increased, the nitrite content remained low. Therefore, if you eat fresh toon sprouts, you will not suffer from nitrite poisoning. However, after harvesting, a large amount of nitrate will be converted into nitrite during storage at room temperature, posing a safety hazard. This is the reason why the nitrite content of toon sprouts is so high. That is to say, it is safe to eat freshly picked toon buds from the tree immediately, but the toon buds purchased from the market will have a significantly increased nitrite content because they have gone through the transportation process. If the leaves fall off at the touch of a finger, a large amount of nitrite will inevitably be produced.

Third, blanch to remove nitrates and nitrites. If the toon sprouts are not fresh enough, but the aroma is still there and it is a pity to throw them away, you might as well blanch them. Blanching in boiling water for about 1 minute can remove more than two-thirds of the nitrites and nitrates, while also better preserving the green color of the toon. Whether it is a cold dish, stir-fry or deep-fried Chinese toon fish, you might as well blanch it first, which can greatly improve the safety of eating Chinese toon. Since the aroma components of toon mainly come from essential oils, which are insoluble in water, blanching will not significantly affect the flavor of the dish.

Fourth, toon should be blanched before quick freezing. Toona sinensis is a seasonal vegetable, and many people like to freeze it and eat it year-round. However, the Chinese toon must be blanched before quick-freezing. Research data shows that blanching for 50 seconds before freezing not only greatly improves safety but also better preserves vitamin C. After being frozen for 2 months, the vitamin C content in the blanched toon was equivalent to 71% of the fresh product, while that in the unblanched product was only 35%. At the same time, whether in terms of color or flavor, it is more ideal to blanch and then freeze. After blanching, put it into a sealed plastic bag and place it in the freezer. It can be stored for more than 1 month and maintain its green color and aroma.

Fifth, it takes longer to pickle toon buds than to pickle Chinese toon. Many people like to pickle Chinese toon with salt for two or three days before eating it. This is a very unsafe habit. After the Chinese toon is pickled, the nitrite content will rise rapidly, reaching a peak in three or four days (when the added salt amount is 10%~20%), and the content is far higher than the permitted standard. Blanching before pickling can greatly reduce the nitrate content, thus reducing the risk of pickling Chinese toon. However, the safest way is to pickle the blanched Chinese toon for a week before eating it after the nitrite content is reduced. Adding ingredients such as vitamin C and tea can reduce the nitrite content in pickling. Finally, eat toon with foods rich in vitamin C. The vitamin C content of toon itself is higher than that of ordinary vegetables and fruits. If you can eat fresh toon, vitamin C can help block the formation of carcinogens such as nitrosamines. If the Chinese toon is not fresh enough, you might as well eat it with other fresh vegetables and fruits to avoid the hidden dangers of nitrite. Studies have shown that when the molar ratio of vitamin C and nitrite is 2:1, the synthesis of nitrosamine carcinogens can be effectively blocked.