Foreign packaging food sterilization technology

With the rapid development of the production of packaged foods, the sterilization technology of energy-saving, safe, reliable, effective and low-cost packaged foods have been developed and applied one after another, which has greatly promoted the production and development of packaged foods.
Irradiation sterilization technology Irradiation sterilization technology is the use of radiation isotope cobalt 60, yttrium 157 production of γ-ray or low-energy accelerator radiation β-ray irradiation of packaged foods. In countries such as Canada, Israel, France, and Japan, cobalt 60 is widely used. The powerful gamma rays it emits can completely destroy the genetic factors of bacteria and completely destroy their vitality. When high doses are used, almost any bacteria can be eliminated.
Irradiation sterilization according to the dose can be divided into complete radiation sterilization and radiation sterilization.
Irradiation is completely sterilized, and the sealed packaged food is irradiated with 2500-5000 kilorads, so that all pathogenic microorganisms that damage the food can be killed to achieve the purpose of product sterilization. Adding salt and sodium tripolyphosphate to the food before irradiation can reduce the moisture loss of the food and enhance the ability of rays to kill bacteria. The beef, chicken, ham, pork, sausages, fish, and shrimps that have been treated with the irradiation complete sterilization method can be stored at room temperature (21° C. to 38° C.) for more than 2 years, and the color and flavor are still good.
Radiation sterilization. A dose of 100 to 1000 kilorads can effectively limit the growth of organisms and detrimental microorganisms that are detrimental to the health of the general public. It can use 500,000 rads to remove salmonella that are extremely harmful to protein-rich foods such as meat, dairy products and egg products. Irradiation can make it hundreds of millions of times smaller, and it can also kill Salmonella deep inside frozen foods. More than 20 countries around the world have approved the use of radiation-sterilized foods for human consumption, such as chicken, pork, fresh fish, mushrooms, spices, potatoes, rice, onions, and wheat. Irradiated food is safe and reliable. After more than 40 years of practice by experts from various countries in the world, it has been proved that irradiated food has never been found to have radioactive material residues and can maintain its original quality and color and flavor. In the United States, irradiated foods have been brought into space, and astronauts have proved to be harmless to the body after eating. The advantage of long-term preservation of irradiated foods is that they can be kept fresh for a few years, killing bacteria, inhibiting and delaying the metabolism of the food itself, and eliminating the root causes of food deterioration. Irradiation of food data can save a lot of energy. Any food can only be stored in ordinary packaging with the irradiation method, which saves a lot of materials such as can making, freezing and refrigerating, and energy. Irradiation preservation can replace some refrigerators.
Ultraviolet rays radiate ultraviolet rays, that is, use ultraviolet rays to kill the DNA of the target microorganism to chemically change the pyrimidine dimer to destroy the genetic element and lose reproductive ability or death. The sterilization effect is the strongest at 250 to 260 nm. The powerful UV lamp developed abroad has an irradiation intensity of 200mw/cm2. It is a high-performance UV device and is safe and effective for sterilization of packaging materials.
Ultraviolet sterilizing equipment is divided into solid surface sterilization and liquid sterilization according to the sterilization method.
The solid surface sterilizer is used to transport packaged foods through conveyor belts into the irradiation track, sterilize them with germicidal lamps, and then send them out with conveyor belts. Foods that are suitable for plastic film packaging require polyethylene with high light transmittance. Or polypropylene plastic film.
Liquid sterilizers can be divided into two types: liquids, one side with a sterilizing lamp, one with an external exposure to the outside, and one with an internal illumination that allows water and liquid to flow from the inside. The bactericidal effect can reach zero from the initial concentration of 105/ml after irradiation.
Ultraviolet sterilization requires little or no addition of bactericides and preservatives. It is more energy efficient and less costly than heat treatment and filter sterilization methods. It is easy to maintain, safe and reliable to use, and does not damage food flavors and luster after sterilization. It is widely used. . The United States has successively developed a series of products. UV lamps that emit dozens of times more than the past have been put into practical use and have been gradually used for transmission. Ultraviolet sterilization, such as with heating, hydrogen peroxide, hot citric acid solution, ethanol, ultrasound and other treatment methods, the effect is better.
Microwave Sterilization Microwave disinfection is the use of microwaves to make water molecules vibrate and use molecular friction heat to sterilize. It is characterized by the use of plastic packaging materials for foods with poor thermal conductivity and foods that are easily degraded due to heating. They can be pasteurized and sterilized from the food center within a short period of time under packaging and can prevent secondary contamination. After the Soviet Union packaged bread was microwaved, it remained fresh and sweet within three weeks. Microwave sterilization is only applicable to heat-labile microorganisms such as molds, yeasts, and E. coli. However, for foods with low moisture content attached to the back of foods, and microorganisms without moisture or induced small plastics or glass, the temperature cannot be fully increased. The effect is not significant.
The microwave heating method has two types, an oven or a tube type, and the latter is applied to a treatment liquid, and the liquid is heated by flowing through a glass tube that is oblique to the catheter.
Aseptic packaging technology Aseptic packaging technology is a packaging technology in which sterilized and cooled aseptic foods are filled in a pre-sterilized container and sealed for long-term storage under aseptic conditions. In the past ten years, aseptic filling has progressed from fluids to solids, and packaging materials have moved from metal cans to packaging materials. Aseptic packaging technology has developed rapidly in Europe, America, Japan, and is widely used in milk-based dairy products, juices, puddings, and meats. Processing foods such as vegetables, vegetable juices, broths, cool drinks and coffee drinks, soy milk and other fields.
Aseptic packaging has a lot of advantages: less changes in product flavor, tissue color, loss of nutrient components, and thermal denaturation of proteins, no fat deposition and gravy separation of aseptically packaged meat products, and better preservation of original taste and flavor, aseptic The packaged juice is easy to keep, fresh and practical. Aseptic packaging is stronger for packaging containers.
Low requirements, thin materials, can be made of cardboard, plastic, aluminum and other materials. In particular, the low-container cost is low, the weight is light, there is no metal dissolution, it is disposable, and the handling is simple. 70% of U.S. drinking milk is packed in paper. Aseptic packaging also has the advantages of saving energy and being suitable for mass production.
Aseptic packaging systems include the sterilization of food and the aseptic filling and sealing of two major departments. Food sterilization usually uses high-temperature short-time sterilization process (HTST method) and ultra-high temperature instant sterilization method (UHT), composite films made of heat-resistant plastic film and aluminum foil, can greatly shorten the sterilization time. Sterilization of soft packaging materials used for aseptic filling and packaging generally uses ultraviolet sterilization, radiation sterilization and hydrogen peroxide solution impregnation, spraying, hot air drying, or sterilization with gas germicides.
The typical aseptic packaging device in the world includes the aseptic canning of Dole Inc. in the United States, which is used for fluids, colloids, and foods containing solids in metal cans, such as various puddings, condensed milk, paste-like foods, yoghurt fresh milk, and the like. The aseptic filling equipment consists of four parts: empty can, sterilizing, filling, sterilizing and sealing the can. When the empty cans are sterilized at 210°C-220°C for 45 seconds and enter the sterile room, the sterile water is sprayed from the lower part to cool the empty cans. Generally, the tanker can be used for continuous canning. Japan's MM aseptic filling device is to sterilize the styrene plastic film with hydrogen peroxide, heat the formed film and press it into a ring-shaped container, automatically fill it with a fixed amount, and send the aluminum foil that has been sterilized by hydrogen peroxide, seal it with a sealing mold, and cut off the film. For pudding, jam, ice cream, milk, juice and other aseptic filling.
In the process of aseptic packaging, in addition to the sterilization and sterilization of packaging materials and packaged foods, the whole operations of the workshop, working machinery, and air must be cleaned and sterilized, and the microbiologically controlled production management and circulation management must be thoroughly implemented.
Other Packaged Food Sterilization Technology The competitive development of foreign packaged food products has led to the development of more applicable new sterilization technologies. For example, the flame sterilizing method that enables direct heating of cans with gas flame during high speed rotation can accelerate heat conduction and prevent non-uniform heating. It is effective for canned foods and retort pouches; there is no need for sterilization of packaging materials, and food processing equipment is simple. The unique method of sterilizing liquid foods; the use of superheated steam to sterilize dried foods by air-disinfecting method will not make the raw materials damp like saturated steam, and it has good effect on grains and powdery foods.