Radiation preservation of the hottest food

Radiation preservation of food

the history of human struggle to prevent food deterioration may be as long as human history itself. The losses caused by the deterioration of food all over the world are amazing. According to the estimation of the United Nations Food and Agriculture Organization, the loss caused by the deterioration of food produced all over the world accounts for about a quarter to a third. Undoubtedly, this is a very serious problem, especially today, when many people on the earth are still hungry and semi hungry, the situation becomes more acute. Some methods used by people to prevent food deterioration, such as cooling and heating, have achieved remarkable results, but they consume too much energy, aggravating another worldwide problem - the tension of energy supply. Another way to prevent food spoilage is to add chemical additives. However, this method leads to the harm of residual chemical additives in food, and there are many important toxic chemical arguments strongly opposed to this method. People have successfully applied ray sterilization to prevent food from spoilage, and formed a new industry of ray preservation and storage of food. Many food ray preservation and storage plants have been established in the world. In Savannah, the United States, there is the world's first radiation device for irradiating bulk grain, which can process about 2000 kg of bulk wheat per hour, with a maximum processing capacity of 5000 kg per hour. In Takasaki, Japan, there is a radiation preservation and storage plant that can handle 1000 tons of food per month, and a radiation irradiation plant that can handle 1060 tons of potatoes per month has been built in Sapporo. Figure 7.2 shows a 60Co project built in Sichuan, China γ Photos of the radiation source irradiation device during the irradiation and storage of grain

the effect of radiation in the process of food preservation the excellent printing quality created by Tego glidea116 should be

(1) microbiological effect. Radiation can kill microorganisms. With different doses, the purposes of killing insects (eggs, larvae and insects), decontamination (eliminating microorganisms without spores) and sterilization (eliminating all microorganisms) can be achieved respectively

(2) physiological effects. Radiation can inhibit germination (such as potatoes, onions, carrots, etc.) and delay growth and maturation (such as fruits, mushrooms, etc.)

(3) physical effects. It is mainly manifested in changes in permeability, such as drying vegetables and shortening cooking time

main advantages of food preservation by radiation

compared with other methods, what are the advantages of food preservation by radiation? There are mainly the following:

(1) it is the only method that allows food to be packaged and then processed. This advantage is obvious. It can completely avoid serious cross infection in the process of food processing

(2) foods that can usually be eaten raw, such as beef mayonnaise, raw sausage, oysters, etc., can be guaranteed to be safe from a biological point of view. Especially for those animal foods, this treatment is very necessary, and there is no need to be careful about residual chemical additives

(3) the energy consumption is relatively low, and the energy required is much lower than that of cooling method and heating method. According to statistics from the 1970s to 1980s in the United States, the cost of food irradiation in the United States is about $0.01/kg (only one cent per kg)

(4) it is also found that radiation can improve the quality of some foods without warping. For example, irradiation of new wine with rays can accelerate its aging and esterification, shorten the cellar storage time, and improve the quality of wine. For another example, radiation can shorten the cooking time of dried vegetables, enhance the rehydration ability of dried fruits, improve the digestibility of soybeans, and so on. For example, the cooking time of dried potatoes can be shortened from 20 minutes to 4 minutes after irradiation

required radiation dose

due to different objects and purposes of irradiation, the required radiation dose is different, and there are generally the following three differences:

(1) low dose irradiation. Generally, it is less than 10000 to 50000 rads. It is used to make pests in grain depots sterile or kill them. It can also be used to delay the physiological changes of plants, inhibit the germination of potatoes and garlic, and delay the maturation of tomatoes and bananas

(2) moderate dose irradiation. Generally, it is between 100000 to 1million rads. The purpose of irradiation is to kill a large number of corrupt microorganisms and prolong the preservation period of food, such as the ray preservation of meat, shellfish, eggs, fruits, vegetables, etc

(3) high dose irradiation. Generally, it is more than 1million rads for complete sterilization. It is mainly used for the ray preservation of animal food such as meat, fish, shellfish, bacon and canned food

ray technology has opened up a new way for food preservation and storage, which has attracted the attention of all countries in the world. By the early 1980s, 60 countries in the world were engaged in the research and development of food ray preservation and storage, and established about 70 food radiation factories. The ray preservation foods officially approved for public sale by many countries include onions, potatoes, garlic, dried fruits, fresh fruits, mushrooms, asparagus, cocoa seeds, condiments, wheat, strawberries, beef, pork and their products - rabbit meat, chicken, COD, shrimp Dozens of kinds of food such as sterile food for astronauts and special patients. Now let's take a look at two pictures of real objects

(1) figure 7.3 shows ham steak: passing on the left γ The irradiated smoked ham steak, and the one on the right is the ham steak that has not been irradiated. This photo was taken after they were put together at room temperature for 9 months. It can be clearly seen that the effect of ray preservation is very obvious. The ham steak treated with ray preservation on the left still retains its original color, which is exactly the same as the fresh ham steak; The ham steak that has not been irradiated has turned gray, and it is obvious that it has completely deteriorated

(2) Fig. 7.4 is a picture of potatoes: the right is treated with radiation preservation, and the left is not treated with irradiation. Their storage conditions and time are exactly the same. As a result, long buds have grown without radiation preservation treatment, while there is no difference between the irradiated potatoes and the newly harvested ones, and the effect of preservation is very obvious

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