2. put it in a fresh-keeping box and put it in a cool and ventilated place, which can be kept for a week.
3. Put the Toona sinensis into a clean fresh-keeping bag, put it in a pocket, and put it in the refrigerator for cold storage at the temperature of 0- 1 Celsius. It can last for about 20 days.
4. First blanch the Toona sinensis in boiling water and roll it quickly. After the color turns green, immediately put it in cold water, let it cool, drain the water, spread it out to dry, put it in a fresh-keeping bag, put it in a pocket and put it in the refrigerator for one year.
Toona sinensis contains nitrate and nitrite, which is much higher than ordinary vegetables. The protein content of Toona sinensis is higher than that of ordinary vegetables, and there is a risk of nitrosamines. Therefore, there is a safety hazard in eating Toona sinensis, and the following principles should be followed:
(1) Select the most tender Toona sinensis bud:
It was found that the contents of nitrate and nitrite in Toona sinensis in different regions, varieties and growth periods were different. The most important thing is that the nitrate content of Toona sinensis is low in the initial stage of germination, and the nitrate content is also rising with the continuous growth of Toona sinensis buds.
After mid-April, the nitrate content in Toona sinensis buds in most areas exceeded the standards of the World Health Organization and the Food and Agriculture Organization of the United Nations. That is to say, the more tender the Toona sinensis buds are, the less nitrate will be produced, and the less nitrite will be produced during storage in the future.
(2) Selecting the freshest Toona sinensis bud:
The determination also showed that the nitrate content in Toona sinensis buds increased after mid-April, but the nitrite content was still low. Therefore, if you eat fresh Toona sinensis buds, it will not cause nitrite poisoning.
However, after harvesting, during storage at room temperature, a large amount of nitrate will be converted into nitrite, which will bring security risks. The so-called high nitrite content in Toona sinensis buds is precisely this reason.
(3) blanching to remove nitrate and nitrite
If the Toona sinensis buds are not fresh enough, but the fragrance is still there, it is a pity to throw them away. It is better to blanch them. Blanching with boiling water for about 1 min can remove more than two thirds of nitrite and nitrate, and can also preserve the green color of Toona sinensis.
Whether it's cold, stir-fried or fried Toona sinensis fish, you might as well blanch it first, which can greatly improve the safety of eating Toona sinensis. Because the aroma components of Toona sinensis mainly come from essential oil, which is insoluble in water, blanching will not obviously affect the flavor of dishes.