What Is Sterile Packaging?

Aseptic packaging refers to the use of aluminum foil as a barrier material to make rectangular carton packaging with straw straws (when drinking soda).

Four elements of aseptic packaging

Introduction to Aseptic Packaging

Food aseptic packaging refers to the products that have been sterilized after being sterilized, and are sealed in sterilized containers and filled in a sterile environment. After filling, the packaging containers are kept sealed to prevent re-infection. Preservative, packaging method to obtain longer shelf life without refrigeration.

Aseptically packaged foods do not need to be added with preservatives, and can be maintained at room temperature for one to one and a half years without deterioration, which greatly saves energy and equipment; because the sterilization time of sterile food packaging is short, the nutritional content of the food is destroyed It has less color and taste, and is widely used in milk, yogurt, juice and other packaging.

Aseptic packaging is divided into large packaging and small packaging. The former has a packaging capacity of 5-220L and the maximum can reach 1000L. It is mainly used by food manufacturers for packaging and sales; the latter has a packaging capacity of 70-1200ml for market sales and direct supply and consumption. By.

Aseptic packaging includes the four elements of sterility of packaging materials, sterility of packaged products, sterility of packaging environment, and complete sealing after packaging. "Sterile" indicates that the product does not contain any microorganisms that affect the quality of the product. "Complete sealing" indicates that the product is sealed into a certain volume of packaging through appropriate mechanical means, which can prevent microorganisms and gas or water vapor from entering the packaging. ^[1] .

Aseptic packaging materials

Aseptic packaging materials are generally metal cans, glass bottles, plastic containers, composite cans, paper-based composite materials, multilayer composite flexible packaging and so on.

Aseptic packaging

The sterilization of food materials is divided into heat sterilization and cold bacteria. The sterilization of materials in food aseptic packaging has so far mainly been thermal sterilization, which is divided into two types: ultra-high temperature sterilization and high-temperature short-term sterilization. The cold sterilization methods of materials mainly refer to ultraviolet and microwave sterilization. Ultra-high temperature sterilization refers to a process for treating dairy products or other foods under the conditions of temperature and time of 135-150 degrees and 2-8 seconds, respectively. Because it has many advantages, it can solve the contradiction that can not only kill the microorganisms in the product, but also can better maintain the quality and nutritional value of the food. It has been widely used in cow's milk, fruit juice and fruit drinks, soy milk, tea, Production of wine, mineral water and other products.

For cooking materials with ultra-high temperature sterilization, high-temperature short-term sterilization can be adopted. The sterilization treatment is performed at a temperature of 70-75 degrees and a time of 15-20s. This method can better maintain the nutrition and flavor of the product. Typical applications are sterilization of dairy products and some vegetable products.

Due to the special characteristics of material viscosity, pH value, heat sensitivity, easy oxidation, etc., the sterilization methods and equipment are also different. The pH value often determines the temperature and time when the material is sterilized. The pH value depends on the amount of acidic substances in the food and the degree of separation. Low-acid foods have a pH value greater than 4.6, which can provide ideal growth conditions for pathogenic microorganisms, and spoilage microorganisms can also grow well. Generally, ultra-high temperature instant sterilization is used; the pH value of acidic foods is between 3.7-4.6. Germs are not easy to grow, but spoilage bacteria can grow. Generally, ultra-high-temperature instant sterilization or high-temperature short-term sterilization is used. Low-acid foods can be converted to acidic foods by adding acid or fermentation, thereby reducing sterilization requirements and improving shelf life. This method is used to treat tomato sweat and cheese in food. Highly acidic foods have a pH of less than 3.7, and pathogenic bacteria cannot grow and spoilage bacteria cannot grow under this acidity. Therefore, sterilization is not a problem that requires special attention, and maintaining quality is the primary purpose. Generally, pasteurization can be used to meet the requirements, that is, treatment at 62 degrees for 30 minutes, and ultra-high-temperature instant sterilization or high-temperature short-term sterilization can also be used, depending on the specific situation.

The cold sterilization method of materials refers to various bactericides or ultraviolet sterilization, radiation sterilization, microwave irradiation sterilization, etc. to achieve sterilization according to different occasions. The effect of using microwave sterilization has been well verified in soy sauce, beer, milk, etc., but some technical problems for large-scale production have not yet been resolved.

Sterile packaging environment

The aseptic packaging system is mainly divided into two types of systems, the open aseptic packaging system and the closed aseptic packaging system. The biggest difference between them is that closed aseptic packaging systems have more aseptic rooms than open aseptic packaging systems; packaging materials must be sterilized, shaped, and filled in aseptic rooms. Because the sterile room is always vented with sterile gas to maintain its positive pressure, the sterile room can effectively prevent microbial contamination, so it is widely used in production.

The aseptic packaging environment must first ensure that the equipment is sterile. The main sterilization methods are heating and chemical methods.

For open-type aseptic packaging machines, the surfaces of the packaging machine that come into contact with the product must be sterilized before aseptic filling. The sterilization is achieved by the sterile hot air (or sterile hot steam) generated by the packaging machine itself. During the sterilization process, sterile hot air directly contacts the surface of the packaging machine that is in contact with the product for sterilization. It is not enough to sterilize the closed aseptic packaging machine with sterile hot air. It is also necessary to ensure the sterility of the closed space, that is, the sterilization of the sterile room. Before production, the sterile room is generally realized by the hydrogen peroxide spray and the drying of sterile air. The sterile air is obtained by heating the sterile air heater in the packaging machine to a certain temperature; during sterilization, the liquid hydrogen peroxide is sprayed to The sterile hot air evaporates instantly, so that the mixture of sterile air and hydrogen peroxide gas enters the sterile room for sterilization, and the hydrogen peroxide condensed on the inner surface is dried by the sterile hot air to complete the sterilization of the sterile room.

As the sterilization of the environment, measures such as washing, heating, medicine, and ultraviolet radiation are generally used. The devices that contact food and the entire container surface are sterilized. The space environment is mostly sterilized by drugs. Enter sterile air and maintain a certain positive pressure in the entire system to prevent the invasion of microorganisms from the outside air.

Microorganisms multiply when the equipment is down, which may cause a large number of microorganisms to not be fully killed. Therefore, the equipment should be dried as much as possible after cleaning so that no water or solution remains.

Aseptic packaging seal

Packaging sealing is the last and key link for aseptic packaging, which directly affects the product packaging quality and shelf life. The requirements are to prevent the invasion of microorganisms and gas or water vapor on the one hand, and not to allow the product's own odor and original liquid to overflow.

Most aseptic packaging seals are heat sealed, ultrasonic or film, air sealed, some are folded, sealed, and the pressure should be evenly distributed on the sealing surface. The sealing process conditions such as sealing temperature, time and pressure must have safety margins. , And can be controlled; the sealing surface should avoid product or other dirt pollution; the sealing position must be accurate, especially in the case of thermoforming / filling / sealing in the same machine, the deviation of the sealing position should be prevented.

Aseptic packaging principle

Aseptic packaging refers to the sterilization of materials into sterile or aseptically processed packaging containers under aseptic conditions according to product requirements, and to store them in airtight, airtight, or even airtight In the specific environment of light, the quality can be maintained for a long period of time without refrigeration at normal temperature. It can be seen that aseptic packaging was originally an abbreviation for a special packaging method. However, over time, it has developed into a field or a systems engineering. It includes at least aseptic packaging technology, aseptic packaging technology, aseptic packaging materials, aseptic processing equipment, aseptic packaging machinery and equipment ...

Performance characteristics of aseptic packaging

There are two types of aseptic packaging: refrigerated packaging and room temperature packaging. Refrigerated packaging includes milk roof bags, bricks, pillows and juice roof bags. Room temperature packaging includes sterile bricks, sterile pillows, and hot-filled roof packs. Commonly used paper-plastic-aluminum composite aseptic packaging materials on the market are mainly four kinds of raw materials: cardboard, polyethylene, aluminum foil and ink. Cardboard does not directly contact the contents of the package, but it is an important part of the package, accounting for about 75% of the total package weight. The main function is to strengthen the stiffness and hardness of the package after molding. Food-grade polyethylene in polyethylene aseptic packaging accounts for about 20% of the entire packaging. Its main role is to block liquid leakage and microbial invasion. The weight of aluminum foil in the aluminum foil aseptic packaging only accounts for about 5% of the entire packaging. The main role is to avoid light and block ventilation, keep the contents from being oxidized, reduce nutrition loss, and keep the taste fresh. Inks Inks have very little weight in aseptic packaging, but they are very important for hygiene and safety. The printing inks for dairy and beverage packaging on the market are mainly solvent-based inks and water-based inks.

History of Aseptic Packaging

The rapid development of China's packaging industry has grown from less than 10 billion yuan in output value in the early 1980s to 410 billion yuan in 2005, second only to the United States and Japan, and has become the third largest packaging country in the world. At present, China's packaging industry is at a critical moment of transition and upgrading, and has experienced a development process from small to large. From the single packaging product in the early 1980s to the current six packaging categories. It will take another 20 years to build China into a world packaging power.

With the rapid development of China's economy and the improvement of people's quality of life, the demand for convenience foods such as microwave foods, snack foods and frozen foods will continue to increase, which will directly drive the demand for related food packaging. China's food and packaging machinery industry will Will maintain positive growth for a long time. It is expected that the circular economy will become the main mode of the development of the packaging industry in the future, the recycling of packaging waste resources will be industrialized, green packaging materials will be vigorously developed and developed, and the basic packaging industry will also accelerate its development.

Development Trend of Aseptic Packaging

Aseptic packaging technology not only has a good development space in the dairy industry, but also has made considerable progress in other industries. The technical equipment of a large number of large-scale backbone enterprises in China's beverage industry has approached or reached the international advanced level. In the future, the beverage industry will have great demand for packaging equipment, especially filling equipment for non-gas beverages such as tea and juice. More than 90% of the domestic aseptic packaging material market is still occupied by Tetra Pak and Combibloc. Aseptic packaging materials have a good development trend in China due to their bright advantages. There are also two main reasons. The first is that milk production in China is mainly in the north, and milk consumption in the south is greater than in the north, and the normal temperature packaging of milk is particularly urgent. Secondly, with the improvement of national living standards, the demand for fruit juice and tea beverages has increased year by year. In the next few years, the output and quality of domestic aseptic composite packaging materials will be greatly improved. In the future, it may enter Yili, Mengniu, Guangming and other well-known domestic dairy groups, thereby breaking the monopoly of the collapsed enterprises. The prospects for the development of aseptic packaging are very good. Policy support from relevant national departments is urgently needed. Aseptic packaging products compete in the low-end market with vicious competition and give up the domestic mid-to-high-end aseptic packaging market to multinational companies.

Problems with aseptic packaging

The technology and materials of aseptic packaging are already mature, but in all aseptic packaging made of paper-plastic aluminum such as brick, pillow and roof bags, in all packaging specifications with a packaging capacity of less than 250ml, the naked Straw hole design. These drinking straw holes, which have not passed through any cover, are extremely easy to adhere and hide unclean objects such as dust, bacteria and the like that are harmful to the human body. When consumers do not take the necessary sanitary measures for drinking straw holes, they will directly insert into the drinking straw for smoking, which will bring pollutants into the beverage and bring great health risks to drinking.

Over the years, experts and researchers in the aseptic packaging industry have been exploring and researching the hygienic drinking problem of aseptic packaging for a long time. Fortunately, the industry has invented a "hygienic beverage box" patent technology. In order to prevent consumers from drinking "toxic beverages" at an early date, people of insight strongly urge the government to introduce compulsory hygienic drinking standards for aseptic packaging and quickly convert and apply the "hygienic beverage box" patent technology. The hygienic drinking standard for aseptic packaging has entered the agenda of relevant national departments. Only then will there be truly aseptic packaging on the market, and consumers will be able to "drink assured"!

Hygienic beverage box