Successful research and development of gas replace

The successful research and development of gas replacement packaging for food preservation technology

modified atmosphere packaging is characterized by replacing the air in the packaging with different protective gases for all kinds of food to achieve the purpose of anti-corrosion and fresh-keeping. It has a wider application range and better fresh-keeping effect than a single vacuum packaging. It is a new change in today's food packaging

since the modified atmosphere packaging products for food entered the European and American markets in the 1980s, there has been great development, with an annual growth rate of 25%, and the total packaging volume has exceeded 5billion boxes. The products include fresh food (fish, meat, fruits and vegetables), cooked meat products, dairy products, baked food and noodle food. Since the early 1990s, China has started the development and research of modified atmosphere packaging technology and equipment for food, and now has the preliminary conditions for commercial application, but so far the market development is still in the initial stage. How to develop modified atmosphere packaging food and enter the market is a problem that the majority of food enterprises have been concerned about

the best quality modified atmosphere packaging food the modified atmosphere packaging process of food mainly consists of the following parts: the composition and mixing ratio of protective gas and packaging materials, as well as the shelf life under the premise of adding the best packaging quality when there are higher requirements for the lamp cap toughness. Modified atmosphere packaging is a kind of protective gas composed of two or three gases in CO2, O2 and N2. The composition and mixing ratio of protective gas shall be determined according to the anti-corrosion characteristics of food. Fish are often contaminated by anaerobic Clostridium botulinum, which produces toxins when the oxygen is deficient and the temperature exceeds 4 ℃. Its danger is that the toxins are produced before sensory corruption and are not easy to be detected. Therefore, the protective gas for modified atmosphere packaging of fresh fish shall be composed of CO2, O2 and N2. Modified atmosphere packaging of pork, beef and mutton should not only protect the color of fresh meat, but also achieve anti-corrosion effect. High oxygen environment can maintain the red oxygenated myoglobin in meat. The protective gas should be composed of more than 60% O2 and CO2. Modified atmosphere packaging of fresh fruits and vegetables can delay aging and wilting by reducing O2 and increasing CO2 (such as 5%o2 and 5%co2) to reduce the metabolic activity of aerobic respiration. The protective gas of other cooked food and baking anticorrosive modified atmosphere packaging is composed of CO2 and N2. Most of the anti-corrosion modified atmosphere packaging materials require the use of composite packaging materials with high gas barrier to maintain the composition of protective gas in the packaging. If the shelf life does not need to be very long, the general barrier PA/PE or P including this one - the product parent of nylon, et/PE, can meet the requirements. It is best to use high barrier PVDC or EVOH composite packaging materials for long shelf life. The packaging film of fresh fruits and vegetables acts as a gas exchange film. The gas composition in the packaging is maintained through gas exchange between the film and the atmosphere. PE, PP and PVC films with air permeability are commonly used. However, this film can not meet the packaging requirements of tropical fruits and mushrooms with high breathing speed, and it is necessary to develop films with high air permeability

establish the cold chain of modified atmosphere packaging for food. Most modified atmosphere packaging foods require storage and sales at 0 ~ 4 ℃ in order to protect food safety and quality. At present, the frozen cold chain of food from production, storage and transportation to sales in China is relatively sound, while the cold chain of low-temperature display cabinets, low-temperature cold storage and low-temperature transport vehicles suitable for modified atmosphere packaging products at 0 ~ 4 ℃ has not been established. Therefore, the establishment of a low-temperature cold chain at 0 ~ 4 ℃ is the key for modified atmosphere packaging products to enter the market

high efficiency modified atmosphere packaging production equipment the main equipment for the production of food modified atmosphere packaging is vacuum modified atmosphere packaging machine and gas proportioner. At present, China's packaging manufacturers have been able to provide various bag or box packaging machines, full-automatic vacuum modified atmosphere packaging machines and gas sword finger solid-state lithium battery proportioners for food enterprises. For example, Shanghai JUGANG Machinery Manufacturing Co., Ltd., through technical cooperation with the school of mechanical engineering and automation of Shanghai University and the school of food science and technology of Shanghai Fisheries University, has developed a series of modified atmosphere packaging machines and gas proportioners with bag and box packaging based on the production of vacuum inflatable packaging machinery series products. The developed products include box packaging zqt-1 D400 and map-200 full-automatic controlled atmosphere packaging machines, which adopt programmable logic controller (PLC) and built-in gas mass flow proportioner. Various packaging parameters, such as gas mixing ratio, gas replacement time, heat sealing temperature and time, film sealing traction and mold movement time control, can be automatically controlled through LCD touch setting, which is easy to operate