Thermal sterilization technology
Formerly for the canned food sterilization, thermal sterilization technology has a wide range of applications. The application of heat sterilization technology can effectively kill microorganisms, but this technical means can easily destroy some canned foods that are sensitive to heat, thereby affecting the nutritional content, color and flavor of canned foods. The current research on thermal sterilization technology in my country is mainly to optimize the sterilization conditions and equipment, and the most ideal state of thermal sterilization conditions is to effectively coordinate the temperature during the sterilization process, so that the application of thermal sterilization technology can not only achieve the effect of sterilization, but also try to avoid the impact. Canned food ingredients and flavors. In addition, in the optimization of thermal sterilization equipment, steam sterilization equipment and microwave sterilization technology are mainly used.
1. Air-containing sterilization technology
The application of air-containing sterilization technology is mainly through the optimization of the previous high temperature sterilization and vacuum sterilization technology, which has changed the shortcomings of traditional sterilization technology. The air-containing sterilization technology is usually used in canned fruits, canned vegetables. When using the air-containing sterilization technology, the raw materials of the canned food should be pretreated first, then vacuumed in the environment of the high oxygen barrier flexible packaging bag in the canned packaging, and at the same time, the inactive gas should be added into the can. The jar is then sealed and the food is placed in a multi-stage high temperature and cooled sterilization container to further sterilize the food. Under normal circumstances, the multi-stage heating treatment process of food can include three stages of preheating, conditioning and disinfection. The sterilization temperature and time of each link should be properly adjusted according to the type and structure of the food. Food flavor is destroyed by high temperature.
2. Microwave sterilization technology
When canned food is processed by microwave sterilization technology, it is mainly to ensure that the microorganisms inside the food die or completely lose their activity, and the storage period of the food is prolonged, so as to meet the requirements of canned food. When using microwave sterilization technology to process food, canned food, as the main heating body, can be directly heated inside the canned food with the outside world, without the need to conduct heat energy through heat conduction or convection. It is also faster to use than traditional sterilization technology. It can quickly increase the temperature of canned food, so that the sterilization inside and outside of canned food is more uniform and thorough. At the same time, the energy consumption is relatively Small. The use of microwave sterilization technology is generally divided into two methods: thermal effect and non-thermal biochemical effect, that is, the use of microwaves to process canned food to heat the food from the inside to the outside at the same time.
Due to the influence of the microbial cell structure and the microwave field, the molecules in the canned food are thermally polarized, causing high-frequency oscillation between the molecules, thereby changing the protein structure, and finally inactivating the bacterial cells in the canned food, making it impossible for normal growth, thereby improving the preservation effect of canned food. Non-thermodynamic effects are mainly caused by physiological or biochemical reactions of cells without significant changes in temperature, also known as biological effects. Because the enhancement of the non-thermal effect sterilization effect cannot be quantified, in order to improve the safety of canned food, the thermal effect should also be fully considered in the process design.
3. Ohm sterilization technology
The application of ohm sterilization technology in canned food mainly realizes heat sterilization through resistance. In practical applications, ohm sterilization technology mainly uses electric current to provide the heat of canned food, so as to achieve the purpose of thermal sterilization. The ohm sterilization technology is generally widely used in canned food with granule.
It can comprehensively reduce the processing cycle of granular canned food, and also has a strong sterilization effect. However, ohm sterilization technology is also limited by various factors, such as when dealing with large-sized granules of food, it cannot achieve good results. At the same time, the conductivity of canned food also affects the sterilization effect of this technology. Therefore, when sterilizing some non-ionized canned foods such as purified water, fat, alcohol, etc., ohm sterilization technology cannot be used, but ohm sterilization technology has a good sterilization effect on canned vegetables and canned fruits, and is also in this field. has been widely used.
Cold sterilization technology
In recent years, people’s requirements for the quality of food have been continuously improved. People not only pay attention to the microbial safety of food, but also pay more attention to the nutritional content of food. Therefore, cold sterilization technology came into being. The main feature of cold sterilization technology is that in the process of food sterilization, there is no need to use temperature changes for sterilization. This method can not only retain the nutrients of the food itself, but also avoid the destruction of food flavor. Bactericidal effect.
In recent years, my country’s cold sterilization technology has been widely used. With the support of modern technology, a wide range of cold sterilization technologies have been introduced, such as ultra-high pressure sterilization technology, radiation sterilization technology, pulse sterilization technology and ultraviolet sterilization technology. The application of technology has played a good role in different food structures. Among them, the most widely used is ultra-high pressure sterilization technology, which has shown good application advantages in the sterilization of juice canned food, but other cold high pressure sterilization technologies are still It is in the initial stage of research and has not been widely promoted and applied.
Ultra-high pressure sterilization technology belongs to the category of physical sterilization. The basic principle of this cold sterilization technology is to generate ultra-high pressure in canned food to kill microorganisms, avoid protein deterioration, and also inactivate biological enzymes to achieve good sterilization. Effect. The use of ultra-high pressure sterilization technology can not only achieve sterilization at room temperature, ensure the nutritional content and flavor of canned food, but also effectively delay the shelf life of canned food, making canned food safer. When processing canned food, ultra-high pressure sterilization technology is widely used in canned jam, canned juice and other foods, and has played a good role in sterilization.
Hurdle sterilization technology
Cold sterilization technology is more advantageous than heat sterilization technology to a certain extent. It can effectively inhibit the microorganisms in canned food. It also solves the problem that traditional heat sterilization technology destroys the nutrients and flavor of canned food, and further satisfies people’s strict requirements for food. Require. However, although cold sterilization technology can effectively inhibit spoilage microorganisms in canned food, it cannot achieve good results in the treatment of bacterial spores or special enzymes, so the application of cold sterilization technology is relatively limited. Therefore, people have developed a new sterilization technology – hurdle sterilization technology. This technology has changed the mode of cold sterilization technology and can play a good sterilization effect in low-intensity links. Hurdle sterilization technology first originated in Germany, people use hurdle sterilization technology for meat preservation. In the process of preserving canned food, since the video includes multiple hurdle factors, these hurdle factors can effectively prevent the deterioration of canned food, and the microorganisms inside the canned food cannot cross the hurdle, which leads to the hurdle effect. Thereby, a good sterilization effect is achieved, and the quality of the canned food is improved.
At present, the hurdle sterilization technology has been fully researched and applied in my country. The sterilization of canned food through the hurdle sterilization technology can avoid the phenomenon of food acidification or rot. For some canned vegetables such as bean sprouts and lettuce that cannot be sterilized by high temperature, the advantages of the hurdle sterilization technology can be fully utilized, and the hurdle can be fully utilized. The bactericidal factor not only has a bactericidal effect, but also prevents the canned food from being acidified or rotten. In addition, the hurdle sterilization technology can also play a good role in the sterilization of canned fish. The pH and sterilization temperature can be used as hurdle factors, and the hurdle sterilization technology can be used to process canned food, thereby improving the quality of canned food.
Post time: Sep-07-2022