The necessity of aseptic packaging technology for food packaging

[Chinese Packaging News] Because of the continuous contamination of various microorganisms in the process of production, packaging, transportation, and storage, articles have a large variety of microorganisms. Although it can be sterilized using chemical agents, modified atmosphere, high temperature, and low temperature sterilization technology. However, sterilization alone is not enough, because many items cannot be kept in the sterilization environment, especially certain foods, so the aseptic packaging technology is widely used in food packaging. The so-called aseptic packaging technology is a kind of packaging technology that fills and seals in a sterile environment in the case of a packaged object, a packaging container or a material, and a package assisting device being sterile. The main research object of aseptic packaging technology is food and beverage packaging, followed by packaging of heat-sensitive products (such as medicine). Food aseptic packaging means that sterilized foods (such as beverages, dairy products, etc.) are packaged in a sterile environment and enclosed in sterilized containers in order to obtain long-term preservation without preservatives or refrigeration Shelf life. Here, the author only briefly talks about the application of aseptic packaging technology in food packaging.

With the higher requirements put forward by consumers on the preservation function of food packaging, improving food packaging to prolong the freshness of food has become an important issue for many manufacturers. At present, aseptic fresh-keeping packaging is most popular in the food industry in various countries. Its application is not limited to juices and juice drinks, but also to packaging milk, mineral water and wine. One-third of all beverages in the UK are in aseptic packaging and Canadian apple juice has been treated with aseptic processing. Japan developed a mineral absorbent paper bag with calcium phosphate as a raw material, used to package foods such as vegetables and fruits, so that vegetables and fruits can obtain nutrient supply from mineral concentrates, absorb ethylene and carbon dioxide released from fruits and vegetables, and inhibit the decomposition of chlorophyll. Maintain freshness. The US market launches a fruit preservation bag made of natural activated clay and polyethylene plastic. It is like a very fine filter screen. Gas and water vapor flow through the packaging bag to increase the freshness of fruits and vegetables by more than 1 time, and the packaging bag can be Reuse, easy to recycle, the price is not higher than ordinary plastic bags.

Discovery of sterilization techniques and new technologies commonly used for packaging and packaging containers

1. Ultra-high temperature instantaneous sterilization

Ultra High Temperature Instantaneous Sterilization (UHT) is the purpose of sterilizing foods by heating them to high temperatures in an instant. UHT sterilization temperature is 135 °C -145 °C, only 3 seconds -5 seconds to completely kill microbial spores. The ultra-high temperature instantaneous sterilization method is further divided into direct heating UHT method and indirect heating UHT method.

2. Pasteurization technology

Pasteurization technology is to fill and seal the food in the packaging container, keep the temperature below 100°C for a certain period of time, and kill the bacteria in the packaging container. Pasteurization kills most pathogens, but the ability to kill non-pathogenic spoilage organisms and their spores is insufficient, if pasteurization is combined with other storage methods, such as refrigeration, freezing, deoxygenation, and packaging. , can reach a certain period of preservation requirements.

3. Ohm sterilization technology

Ohmic sterilization is the direct introduction of current through the electrodes into the fluid containing particles, using the dielectric properties of the food itself to convert electrical energy into heat and heating the food. British APV company began researching the ohm UHT pasteurization system in the 1980s and has now developed commercial models ranging from 75kw to 300kw, and was approved and approved by the US Food and Drug Administration (FDA) in 1993. APV's Ohm UHT heating and sterilizing system can be used for the aseptic processing of low acid liquid foods such as high-acid foods or lumpy meats with a particle size of more than 25 mm, like strawberries and kiwifruit. Ohmic heating UHT sterilization system has been widely used in Europe, the United States, Japan.

4. Resistive heating UHT sterilization method

Resistive heating UHT sterilization is based on the fact that most formula foods contain free water with moderately dissolved salt ions and have good conductivity. According to Ohm's law, the current can be heated by continuous current through material channels, and the heating range is A direct heating ultra-high temperature sterilization system involving the uniformity of the food conductivity and the residence time of the food in the electric heater.

At present, with the constant renewal of sterilization technology, aseptic packaging technology has gradually emerged from the traditional model and developed toward a new sterilization method. As a matter of course, sterilization methods for packaging containers are more often used with a combination of high-intensity ultraviolet light and low-concentration hydrogen peroxide. The use of hydrogen peroxide at a concentration of less than 1%, combined with high-intensity ultraviolet light, produces bactericidal efficacy at room temperature that is a hundredfold greater than when used alone. Since the concentration of hydrogen peroxide is very low, no measures need to be taken for residual hydrogen peroxide, which avoids the problems of high temperature and long time for conventional hydrogen peroxide. Another example is the UHT sterilization method and the maintenance sterilization method. The bottled milk is subjected to a secondary sterilization method. The milk is sterilized by a UHT sterilizer at 130°C to 150°C and 0.5S to 15S. After that, the flask is bottled and capped and then sterilized at 110° C. to 116° C. for 15 minutes to 20 minutes. UHT sterilization of milk is basically in an aseptic state, so the heating intensity for maintaining sterilization can be significantly reduced, and the flavor and color of the product can be significantly improved. There is also ultra-high pressure sterilization technology, which is to put the product under a pressure of more than 500MPA for a period of time to kill, killing most or all of the microorganisms therein, inactivating the activity of the enzyme, so as to achieve the purpose of preserving the food. Since the pressure of several hundred MPA does not increase the temperature of the food, there is no deterioration of color, smell, taste, and nutrient components, and the original flavor of the food can be retained more.

Aseptic packaging technology in food packaging and its development prospects

At present, aseptic packaging has become one of the most closely related packaging forms in people's lives in many parts of the world. It has been widely used in the packaging of beverages, dairy products and other foods, bringing unlimited business opportunities to the vast number of food production companies.

Aseptic packaging in food packaging accounted for a larger proportion, such as pouches of sterile milk, the price is cheaper, product flavor is good, and long-term preservation at room temperature, manufacturers, consumers are very welcome this packaging product, The product not only overcomes the limitation of the production area, but also removes the cold chain required in the transportation process, which is conducive to market expansion. According to statistics, aseptic packaging of liquids exceeds 70%, and the global annual consumption of cartons aseptically packs more than 100 billion. At present, there are about 300 sets of aseptic packaging equipment in China, with an annual production capacity of over 1.5 million tons. Swedish Tetra Pak, SIG Combibloc and U.S. International Paper Co., Ltd. are the three giants in the field of aseptic packaging for male trays. With the development of the economy and the improvement of the people’s living standards, the demand for convenience food will inevitably increase, and it will certainly promote the further development of aseptic packaging.

Aseptic packaging PK hot filling packaging, the former will have more advantages to win. Some industry sources believe that sterile plastic packaging will quickly replace hot-filled PET bottles. Their reason is: the bottle body quality is lighter, the price is cheaper, the heat treatment time shortens will further improve the product taste and the nutritional value. The hot filling line consisting of many old equipment in the beverage industry needs to be updated. Gordon Bockner, president of the Business Development Association, is very familiar with the PET market and related technologies. He believes that low-acid beverages in the North American market will be filled aseptically with PET bottles. “Tea beverages, milk, and nutritional supplements such as En-sure and Boost are very suitable for this technology.” Bockner said, “Currently, PET bottles cannot usually be aseptically filled because the FDA bans the use of fungicides other than hydrogen peroxide. Hydrogen peroxide cannot be used in PET materials. Hydrogen peroxide is absorbed by PET, which has a negative impact on product taste."

Ray Bourque, president of Ray-Pak, a packaging consulting firm, also believes that the future of low-acid products is the aseptic filling of plastic bottles. “Especially some new generation beverages are no longer suitable for hot filling in terms of quality or nutrition,” said Bourque. “At the same time, aseptic filling systems have been continuously improved in recent years. The smaller the size, the faster the rotary speed compared to the linear type, the lower the cost of aseptic filling, the more simplified the process and the lower the threshold for aseptic filling.” Aseptic packaging technology is not only in the dairy industry There is good room for development, and there have also been significant developments in other industries. The technical equipment of a large number of large-scale backbone enterprises in the beverage industry in China has approached or reached the international advanced level. The beverage industry in the future will have a great demand for packaging equipment, especially filling equipment and non-aerobic beverages such as tea and fruit juices, and paper and plastic sterilization. The market for packaging and PET bottles aseptic packaging equipment is very promising; the market demand for pre-processing equipment for juice beverages, juice freezing and concentrating devices, diversified packaging equipment and ultra-high temperature sterilization equipment is also very large.

Relevant experts believe that the current level of China's packaging industry lags behind that of developed countries for many years, but this gap also shows the potential for the development of China's packaging industry. As for aseptic packaging products, in developed countries, such packaging has accounted for more than 65% of the entire beverage packaging, and is growing at a rate of 5%-10% each year, and some countries consume more than 100 packets per year. However, China’s per capita annual consumption is only 1 pack, which is far from the level of 20 packs per capita in the world. Therefore, aseptic packaging has great potential for development in our country. With the rapid development of China's economy, food aseptic packaging technology will continue to improve, China's packaging companies should lose no time to research and development of aseptic packaging products, so that aseptic packaging has become a new bright spot for the development of packaging enterprises in China.