Three minutes to talk about popular science
Can irradiated and sterilized food be eaten?When we buy food, sometimes we will find that some foods are marked as irradiation sterilization, which literally means that the bacteria of the food are killed by radiation irradiation, since it is the method of killing bacteria by radiation, then there will be radiation residues on the food, and there is no harm to the human bodyIn this issue, let's talk about irradiation sterilization and see what dangerous radiation is all about.
The so-called irradiation sterilization is naturally a method of using the ability of radiation to kill or inactivate microorganisms, which can be used for disinfection or sterilization in the fields of medical devices, medicines, and food. There are two types of irradiation sterilization: ionizing radiation and non-ionizing radiation. Non-ionizing radiation is very common among the two types of radiation, and even has applications in our daily life, because non-ionizing radiation refers to radiation that does not have the ability to ionize, such as infrared, ultraviolet, etc.
The sterilization mechanism of non-ionizing radiation is to cause damage to the cell membrane, cell wall, enzyme system and DNA of microorganisms through thermal or photochemical effects, making them inactive or dead. The advantage of non-ionizing radiation is that the equipment is simple, easy to operate and does not produce harmful by-products. However, the disadvantage of non-ionizing radiation is that it has weak penetration, can only sterilize surfaces or transparent liquids, and is affected by factors such as the shape, color, and transparency of the product.
Ionizing radiation, on the other hand, refers to radiation with enough energy to cause an atom or molecule to lose electrons and form charged particles, known as ions. Ionizing radiation includes X-rays, rays, and electron beams. The sterilization mechanism of ionizing radiation is to produce free radicals and electrons by colliding with substances, destroying biological macromolecules such as DNA and proteins of microorganisms, resulting in the death or loss of reproductive ability of microorganisms. The advantage of ionizing radiation is that it is highly penetrating and can sterilize products that have already been packaged without producing residual radioactive material.
In fact, the intensity of irradiation sterilization is not as high as everyone thinks, and even in many cases, the use of irradiation sterilization is not the optimal solution. Because purely from the perspective of sterilization ability, the radiation intensity used in food generally only kills bacteria on the surface and shallow layers of food, and the ability to kill bacteria in the deep layers of food is not so strong. If the intensity of radiation is increased, it may affect the protein of the food, resulting in a deterioration of the flavor of the food.
Therefore, for the food industry, irradiation sterilization is more often just an auxiliary means. In contrast, there are more thorough sterilization methods than irradiation sterilization, such as heating. However, the advantage of irradiation sterilization is also because it is non-heat treatment, which has certain benefits for making cold dishes, such as foot soaking and phoenix feet, which are often treated by irradiation sterilization.
In fact, the intensity of radiation in irradiation sterilization, direct irradiation to the human body may cause some harm to the body, but after irradiation of food, because there is no radiation source, there is basically no problem of radiation residue. Instead of worrying about radiation, it is better to think about the taste of irradiated food, because the free radicals that may appear in the radiation process will induce oxidation, resulting in some secondary oxidation products, which will affect the taste.
In general, irradiation sterilization is a normal food sterilization process, which is generally used for non-heat treatment of food, and if it is a heat-treated food, there are many more thorough and efficient sterilization methods than irradiation. In fact, in addition to food, many medical devices or drugs will also be treated by irradiation sterilization. Therefore, irradiated and sterilized food can be eaten with confidence. In any case, radiation is certainly risky, but as long as it is used wisely, it will not only cause no harm to people, but will create better living conditions for people. So what other foods do you know that are sterilized by irradiation?