Frozen vegetables are a type of frozen food, which is a small packaged food made by processing fresh vegetables such as chili peppers, tomatoes, beans, cucumbers, etc., and freezing them at the lowest possible temperature and as quickly as possible.
Many people believe that frozen foods are not healthy, and therefore even consider frozen vegetables to be less fresh and nutritious than ordinary fresh vegetables. However, the latest research shows that the nutritional value of frozen vegetables is actually higher than that of ordinary fresh vegetables.
Once vegetables and fruits are harvested, the nutrients gradually degrade and are lost. When most agricultural products are delivered to the market and put on shelves, the nutrients are not as fresh as when they were first picked.
Sometimes farmers harvest vegetables and fruits before they are ripe for the convenience of long-distance transportation or to maintain good appearance. The time it takes for vegetables and fruits to develop complete vitamins and minerals will be reduced. Even if the appearance of vegetables and fruits continues to mature, their nutritional content is no longer comparable to that of fully ripe vegetables and fruits. In addition, fruits and vegetables come into contact with a lot of heat and light during transportation, degrading some nutrients, such as fragile vitamins C and B1.
However, frozen vegetables are usually frozen rapidly during the peak ripening period, during which the nutritional value of the fruits and vegetables is exactly the highest. They can lock in the most nutrients and antioxidants, retain the freshness and nutrients of the vegetables, and do not affect their flavor.
This processing method causes the water in vegetables to quickly form regular and small ice crystals, which are evenly distributed within the cells. The vegetable tissue will not be damaged, and the biochemical processes inside the vegetables cannot be carried out, so bacteria and molds cannot develop. Quick frozen vegetables are very convenient to eat, and there is no need to wash or cut them indoors. They can be thawed slightly. Because most frozen vegetable products have been steamed, and some may also be seasoned with salt, they are cooked over high heat and quickly cooked. Their taste, color, and vitamin content are almost the same as fresh vegetables.
In May 2003, Japan implemented "import self elimination" measures on frozen spinach exported from China to Japan, citing excessive residues of chlorpyrifos, resulting in the de facto suspension of China's frozen spinach trade and causing significant losses to Chinese export enterprises. China's export enterprises have strengthened their supervision and management efforts. Since June 2004, when China resumed exporting frozen spinach to Japan, there have been no instances of excessive residues of chlorpyrifos.