Chinese toon contains nitrate and nitrite, the content is much higher than that of ordinary vegetables, while the protein content of Chinese toon is higher than that of ordinary vegetables, and there is a risk of carcinogenic nitrosamines, so eating Chinese toon has a potential safety hazard. So how to eat Chinese toon is safer? How to deal with it better before eating Chinese toon?
First, choose the most tender Chinese toon bud
The results showed that the contents of nitrate and nitrite were different in different areas, varieties and growing periods. The most important thing is that the nitrate content of Chinese toon is low in the early stage of germination. With the growth of Chinese toon buds, the nitrate content is also rising. By mid April, the nitrate content of Toona sinensis buds in most areas exceeded the standards of who and FAO. That is to say, the more tender the Chinese toon bud is, the less nitrate it contains, the less nitrite it will produce in future storage.
Second, choose the freshest Chinese toon bud
The results also showed that, after mid April, the content of nitrate in the buds of Toona sinensis was still low even though it increased. Therefore, if eating fresh Chinese toon buds, it will not cause the problem of nitrite poisoning. However, in the process of storage at room temperature after harvest, a large number of nitrates will be converted into nitrites, which will bring security risks. The so-called high nitrite content in Chinese toon bud is the reason.
That is to say, it is safe to eat the fresh Chinese toon buds picked from the trees immediately, while the content of nitrite in the Chinese toon buds purchased from the market will increase greatly because they have been transported. If it's time for the leaves to fall off, a lot of nitrite will be produced.
Third, blanching to remove nitrate and nitrite
If the Chinese toon bud is not fresh enough, but the fragrance is still there, and it's a pity to throw it away, then you might as well blanch it. Blanching in boiling water for about 1 minute can remove more than two thirds of nitrite and nitrate, and also can better preserve the green color of Chinese toon. Whether it's cold mix, stir fry or fried Chinese toon fish, you can blanch it first, which can greatly improve the safety of eating Chinese toon. Because the aroma components of Toona sinensis are mainly derived from essential oils, they are insoluble in water. Therefore, scalding does not significantly affect the flavor of dishes.
Fourth, blanch before freezing
Chinese toon is a seasonal vegetable. Many people like to keep it frozen and eat it every year. However, the Chinese toon should be blanched before freezing. Research data show that blanching for 50 seconds and then frozen storage, not only the safety is greatly improved, but also vitamin C can be better preserved. When frozen for 2 months, the content of vitamin C in scalded Chinese toon was 71% of fresh product, but only 35% of fresh product. At the same time, whether it's color or flavor, it's better to scald and then freeze. After blanching, put into a sealed plastic bag, put it in the freezer freezer, it can be stored for more than 1 month, keeping the green and fragrant characteristics.
Fifth, pickle Chinese toon buds for a long time. Finally, eat Chinese toon with foods rich in vitamin C
Many people like to salt Chinese toon for two or three days before eating, which is a very unsafe habit. Because after curing, the content of nitrite will rise rapidly, and reach the peak in three or four days (when the amount of added salt is 10% ~ 20%), which is far beyond the permitted standard. After blanching, pickling can greatly reduce the nitrate content, and also reduce the risk of pickling Chinese toon. But the safest way is to marinate the blanched Chinese toon for 2 weeks, and then eat it after the nitrite content has decreased. Adding vitamin C, tea, ginger, garlic and other ingredients can reduce the content of nitrite in pickling.
Finally, Chinese toon and vitamin C rich food to eat together.
The content of vitamin C in Chinese toon is higher than that in common fruits and vegetables. If we can eat fresh Chinese toon, vitamin C can help to block the formation of carcinogen nitrosamine. If the Chinese toon is not fresh enough, you can eat it with other fresh fruits and vegetables to avoid the hidden dangers of nitrite. It has been proved that when the molar ratio of vitamin C and nitrite is 2:1, the synthesis of nitrosamine carcinogens can be blocked well.
In a word, the safety of eating Chinese toon can be guaranteed by sprouting, fresh eating, scalding and slow pickling.