The key to the aseptic processing and packaging of fruit and vegetable juice beverages

Aseptic processing and packaging technology Application status Aseptic processing and packaging technology was born in the 1930s, and has a history of more than 70 years. In these 70 years of development, aseptic processing and packaging technology has crossed two glorious milestones. The first was the development of a tinplate canister aseptic packaging system by Martin-Dole of the United States in the early 1940s. This system uses a direct or indirect heater to pre-sterilize the food, disinfect the tin can with superheated steam, and fill and seal in a sterile environment sterilized with superheated steam. Second, in the early 1960s, Sweden's Loelinge & Regez developed a packaging system that uses hydrogen peroxide to sterilize soft packaging materials for dairy production. This system uses steam direct spray germicidal milk and uses hydrogen peroxide to sterilize packaging materials. The system is now a TetraPak aseptic packaging system. In addition to the use of steam and hydrogen peroxide as a disinfectant for packaging containers, many other important packaging products have been developed over time as technology advances. Materials sterilization methods, including strong UV, hot air, γ-ray irradiation, thermoforming and so on. The development and successful application of these new sterilization methods have resulted in an assortment of aseptic packaging systems that have been repeatedly used to build new products, not only for a wide variety of packaging materials and containers, but also for different packaging capacities. Today, more than 30 companies in the world provide a variety of different types of aseptic processing and packaging systems.
At present, 80% of the world's retail sterile soft packaged foods are milk or dairy products, and almost 90% of the US sterile small packages (retail capacity) are juice beverage products. A large number (220L) of aseptic packaging is widely used in the United States and is mainly used in tomato pulp and fruit pulp products.
China's aseptic packaging technology presents a bright prospect of flourishing development. There are now a wide variety of aseptic processing and packaging systems of various types. Although most of these systems are imported, there are also many domestically produced equipment. China's aseptic small packaged products are mainly fruit juices, juice drinks, milk and milk containing materials. Large-capacity aseptic packaging products are mainly tomato pulp and concentrated juice, such as apple juice concentrate.
Most of today's aseptic processing and packaging technologies can only be used to produce homogeneous liquid foods. There are many research and development efforts for the aseptic processing and packaging of granular foods. In particular, aseptic processing and packaging systems for low-acid block foods will take years to be used in the industry.
Despite this, aseptic processing and packaging technology has played an important role in the food industry, and it deserves to be a splendid “artistic flower”.
Basic requirements for aseptic processing and packaging Aseptic processing and packaging are processing techniques that fill pre-sterilized products in a sterile environment and seal them in sterile containers. Sterile packaging products can be stored at room temperature for extended periods of time.
Aseptic packaging uses three basic terms: aseptic system, aseptic processing system and aseptic packaging system.
The aseptic system refers to the entire system needed to produce a sealed, packaged, commercially sterile product, including a product sterilization system and a packaging system.
An aseptic processing system is a system that sterilizes the product and delivers the sterile product to the packaging equipment.
The aseptic packaging system includes all equipment that fills and seals the sterile product in a sterile container under aseptic conditions.
Aseptic processing of key technologies. The main components of the aseptic processing system, ie, the product sterilization system, are a transfer pump, a heater, a holding tube, a cooler, a back pressure valve, and a sterile storage tank. As the aseptic packaged product is continuously delivered by the pump, sterilization of the aseptic packaged product is performed continuously, and is also referred to as continuous sterilization.
Continuous sterilization of aseptically packaged products requires the same sterility as conventional canned foods. However, aseptic packaging products are usually HIST and even UHTST sterilized prior to filling the container. Short-term high-temperature and ultra-high-temperature transient sterilization in addition to the same as conventional canned food sterilization, but also its special characteristics.
At present, there is no clear definition for high-temperature, short-time sterilization in the world, but generally it is considered that for low-acid foods with a pH greater than 4.6, sterilization at a temperature of 138 to 145° C. for a time of 1 to 30 seconds is a short-term high-temperature sterilization. Most commonly used procedures for the sterilization of low-acid foods in aseptic packaging. Sterilization temperature is 150 ~ 166 °C, time is 0.1 ~ 0.01s, called ultra-high temperature instantaneous sterilization, a small number of steam direct injection heating product sterilization system has been used. For acidic foods with pH ≤ 4.6, the temperature is 93°C to 96°C for a time of 15-30 s. This is called high-temperature short-term sterilization. More specifically, it should be high-temperature pasteurization. This is the majority of aseptically packaged acidic foods. The bactericidal system uses a sterilization protocol.
The sterilization calculation and control of aseptic packaging products is one of the key technologies for the success of aseptic packaging. Aseptic packaging product sterilization calculation depends on the sterilization temperature and sterilization time. If an indirect heat exchanger is used in the aseptic processing system, in addition to the sterilization value obtained in the holding tube at high temperature, a certain sterilization value is also generated during the heating and cooling process. The combination of the two bactericidal values ​​is the bactericidal value of the entire sterilization process.
The key technology of aseptic packaging lies in the sterilization of packaging materials or packaging containers, as well as the acquisition and maintenance of sterility. In order to achieve these two goals, it is important to monitor and record the critical control points of the aseptic packaging system. Compared with traditional production methods, the automatic recording and monitoring tasks of aseptic systems are much heavier. This is due to the complexity of the inherent technology of aseptic packaging and the relevance of many key factors.
The type of recording and monitoring system used depends on the volatility of various factors in the production process. For example, the preset filling speed fluctuation is very small, and when the filling speed is a key factor, the operator monitors to ensure that the filling speed is within the critical limit. But if the key factor is temperature, the situation will be very different. Since the temperature is affected by many factors and the volatility is large, an automatic temperature recorder or monitor is required.
Aseptic packaging systems have two types of records: one is production records, and the other is meter records. Instrument records provide a continuous record of the operating status of the aseptic packaging system. For the automatic recorder, the operator should keep the recording paper clear and mark the time when the start of sterilization, production or sterilization ends, and the end of production. If for some reason the sterilization temperature is too low, sterile air pressure is insufficient or there is a problem with the filling and the production is stopped, the time for stopping production and restarting production should be indicated on the recording sheet. Production records are manual records of the aseptic system maintenance process. The operator should indicate on the record when the incident occurred and any information related to the corrective action.
For aseptic storage tanks, the records should indicate that the tanks have been sterilized and that the pressure of the sterile air in the tanks is normal. If sterile air is generated by the filter, the sterilization temperature and time of the filters and the sterile air supply system should be Monitor and record. Records should also indicate that other key factors are met at the beginning of production. The filter media should be replaced at appropriate intervals.