Step 2: Improve the air.
Modified atmosphere packaging What is modified atmosphere packaging?
Modified atmosphere packaging can be defined as "the technology of adjusting the gas environment of food in materials that can prevent gas from entering and leaving".
An important feature of modified atmosphere packaging is to adjust the gas combination in the packaging at the initial stage of storage, so as to inhibit food spoilage and achieve the purpose of maintaining food quality or extending its shelf life. For example, the air in the bag is pumped out and then filled with N2 or CO2 gas to inhibit the growth of anaerobic microorganisms.
After vacuum packaging, the packaged goods are subject to certain pressure due to the imbalance between internal and external pressure, which is easy to stick together. Crispy foods such as fried potato chips are easily crushed. After vacuumizing, the food with irregular shape is wrinkled and unsightly, and the food with sharp corners is easy to puncture the packaging bag. The use of modified atmosphere packaging can solve these shortcomings of vacuum packaging, so that the pressure inside and outside the packaging tends to be balanced, thus protecting the bagged food and making the packaging beautiful.
Modified atmosphere packaging is suitable for Vienna sausages and sausages. 1。
Nitrogen (N2): It only plays an inert filling role, and has no bactericidal effect. Nitrogen reacts with food and is not absorbed by food. For food crystals which are easy to be oxidized and deteriorated, N2 can replace O2, which can effectively delay the oxidation and deterioration of food and maintain the quality of food. 2。
Carbon dioxide (CO2): The normal content of CO2 in the air is 0. 3%, CO2 can promote the reproduction of many microorganisms at low concentration, but it will hinder the reproduction of microorganisms at high concentration.
Is the content of carbon dioxide in the package 10%? 40% can inhibit microorganisms. When it exceeds 40%, the sterilization effect is obvious. In addition, CO2 is easy to form weak acid, which changes the flavor of food.
3。 Oxygen (O2): As a filling gas, it is generally not used alone, but often mixed with CO2 and N2 to form an ideal gas, which is used for inflatable packaging of fresh food. Its function is to keep the activity of cells in fresh food, delay its life process and maintain a certain freshness. Appropriate packaging materials and methods should be adopted.
Modified atmosphere packaging-what is modified atmosphere packaging? What is modified atmosphere packaging?
Modified atmosphere packaging requires both boxes and films. First of all, packaging materials with high barrier to gas and water vapor should be selected to reduce the influence of external gas on gas concentration in packaging.
However, for fruits and vegetables, it is necessary to use materials with certain permeability, and the ratio of permeability of packaging materials to oxygen and carbon dioxide will also affect the packaging quality. It is necessary to use packaging materials with appropriate air permeability to ensure that a small amount of external oxygen penetrates into the box, and at the same time, the accumulated carbon dioxide in the box will also seep out, so as to achieve the purpose of controlling the respiratory intensity of fruits and vegetables and avoid metabolic disorder caused by anaerobic respiration. There are few requirements for boxes, as long as they are suitable for heat sealing conditions, such as many disposable environmental protection food boxes on the market, made of PP, PE and CT, but you should also use the appropriate boxes according to your specific needs.
I don't know if I can help you with my hands, so I can only explain it this way. Modified atmosphere packaging must have requirements for boxes and films.
What is modified atmosphere packaging technology?
Modified atmosphere packaging technology, also known as ventilation packaging, is to put food into a sealed bag, evacuate air, replace the gas environment in the package with selected gas, inhibit the growth of microorganisms, and thus extend the shelf life of food.
There are three kinds of gases commonly used in modified atmosphere packaging: CO2, O2 and N2. CO2 can inhibit the growth of bacteria and fungi (especially in the early stage of bacterial reproduction) and also inhibit the activity of enzymes. The antibacterial effect is good at low temperature, with a volume fraction of 25% and good water solubility. The function of 02 is to maintain oxygenated myoglobin, make meat colorful and inhibit anaerobic bacteria, but it also creates a good environment for many harmful bacteria. N2 is an inert filling gas, which does not affect the color of meat, and can prevent oxidative rancidity, mold growth and parasite damage.
Carbon dioxide and N2 are two main gases in meat preservation. A certain amount of O2 is beneficial to prolong the shelf life of meat. Therefore, it is necessary to choose an appropriate proportion to mix them. In Europe, the gas ratio of modified atmosphere meat is 02: CO2: N2 = 70: 20: 10 or 02:CO2 = 75:25.
At present, the most effective fresh meat preservation technology in the world is modified atmosphere packaging (CAP) system with high CO2 inflatable packaging.
What are the characteristics of modified atmosphere storage?
Modified atmosphere storage is one of the most advanced fresh-keeping facilities for fruits and vegetables in the world. It can not only control the temperature and humidity in the warehouse, but also control the contents of oxygen, carbon dioxide, ethylene and other gases in the warehouse, and inhibit the physiological activity of fruits and vegetables by controlling the gas components in the storage environment, so that the fruits and vegetables in the warehouse are in a dormant state. The practical application shows that the application of modified atmosphere storage to fresh-keeping fruits and vegetables has achieved the best effect in storage period and fresh-keeping quality, which is incomparable to other storage methods.
Characteristics of modified atmosphere storage
1. fruits and vegetables stored in modified atmosphere have a long storage time, which is generally 0.5- 1.0 times longer than that in ordinary cold storage. Users can grasp the storage time flexibly, seize the sales opportunity and create the best economic effect.
2. Fruits and vegetables keep their original freshness and crispness, and their moisture, VC content, sugar content, acidity, hardness, color and weight are almost the same as those of newly picked fruits and vegetables, so they are of high quality and competitive in the market.
3. The fruits and vegetables stored in modified atmosphere warehouse have a process of changing from "dormant" state to normal state after leaving the warehouse, which prolongs the shelf life of fruits and vegetables by 2 1-28 days, which is 3-4 times that of ordinary cold storage.
4. The modified atmosphere fresh-keeping warehouse can create a low-oxygen environment, which can inhibit the growth of molds and pests in fruits and vegetables and minimize the weight loss of fruits and vegetables.
5. For fruits and vegetables that are difficult to be stored in general high-temperature cold storage, such as kiwifruit and jujube, excellent storage effect can be achieved.
What is modified atmosphere storage?
Modified atmosphere storage can greatly reduce the respiratory intensity and self-consumption of fruits and vegetables, inhibit the production of ripening hormone ethylene, reduce the occurrence of diseases and delay the aging process of fruits and vegetables by reducing the temperature, oxygen content and carbon dioxide concentration during storage, so as to achieve the purpose of long-term storage and preservation.
Compared with conventional cold storage, modified atmosphere storage has the following advantages.
1 Long storage time.
2. Good storage quality.
3 storage loss reduction
4. Inhibit mildew and germination.
5 significantly inhibit the production of ethylene.
6 extend the shelf life of sales
Modified atmosphere storage can make a variety of fruits and vegetables produce seasonally, sell all year round or even supply all year round, which largely solves the contradiction between the decay of fresh fruits and vegetables in peak season and off season in China. But it is not omnipotent, it just creates an artificial environment, trying to maintain the original quality of fruits and vegetables, and can not turn bad fruits into better ones. So the stored fruits and vegetables must be good.
Good quality, consistent maturity and consistent shape, and mechanical damage must be eliminated.
What is the pronunciation of modifying the atmosphere?
The fourth modified atmosphere storage in Qi Diao, also known as modified atmosphere storage, is the most advanced fresh-keeping storage method for fruits and vegetables. Based on cold storage, it increases the adjustment of gas composition, and by controlling the temperature, humidity, carbon dioxide, oxygen concentration, ethylene concentration and other conditions in the storage environment, it inhibits the respiration of fruits and vegetables, delays their metabolic process, better maintains the freshness and commodity of fruits and vegetables, and prolongs the storage period and fresh-keeping period (sales shelf life) of fruits and vegetables. Generally speaking, modified atmosphere storage can be better than ordinary refrigeration. The fruits and vegetables stored in modified atmosphere warehouse first "wake up" from the "dormant" state after leaving the warehouse, which can prolong the shelf life (sales shelf life) of fruits and vegetables by 2 1 ~ 28 days, which is four times that of ordinary cold storage.
Find the definition of modified atmosphere refrigeration
Modified atmosphere storage, also known as modified atmosphere storage, is the most advanced storage method for fruits and vegetables. On the basis of cold storage, increase the adjustment of gas composition, and control the temperature, humidity, carbon dioxide, oxygen concentration and ethylene concentration in the storage environment to inhibit the respiration of fruits and vegetables, delay their metabolic process, better maintain the freshness and commodity of fruits and vegetables, and extend the storage period and fresh-keeping period (sales shelf life) of fruits and vegetables. Compared with ordinary cold storage, general controlled atmosphere storage can prolong the storage period by 0.5- 1 times; The fruits and vegetables stored in the controlled atmosphere warehouse first "wake up" from the "dormant" state after leaving the warehouse, which can prolong the shelf life (sales shelf life) of fruits and vegetables after leaving the warehouse by 2 1 ~ 28 days, which is 3~4 times that of ordinary cold storage.
Traditional storage methods of fruits and vegetables include simple storage, ventilation storage, radiation preservation, chemical preservation and refrigeration. Simple storage ventilation storage equipment is simple, with less investment, but the storage effect is poor, the storage period is short, and the decay loss is serious. Radiation and chemical preservation are suitable for some fruits, but there are radiation and chemical residue pollution, so not all fruits and vegetables can be suitable.
Modified atmosphere storage can create the best storage environment for fruits and vegetables at a suitable low temperature by changing the gas composition and relative humidity of the storage environment. Its functions are as follows: Low oxygen (generally 1%-5%) and appropriate CO2 concentration created by modified atmosphere storage can effectively inhibit respiration, reduce the loss of nutrients in fruits and vegetables, inhibit the reproduction of pathogenic bacteria and control the occurrence of some physiological diseases; Remove ethylene from gas in storage environment, inhibit its ripening effect on fruits and vegetables, and delay the post-ripening and aging process; Increase the relative humidity in the ambient gas to reduce the transpiration of fruits and vegetables, so as to achieve the purpose of long-term storage and preservation of fruits and vegetables.
What is a modified atmosphere cold storage?
The preservation principle of modified atmosphere cold storage is to improve the relative humidity of the cold storage environment and artificially adjust the specific gas components in the cold storage, so as to effectively inhibit the effects of respiration, evaporation, hormones, microorganisms and enzymes, delay their physiological metabolism, delay the ripening and aging process of fruits, prevent deterioration and corruption, and keep fruits fresh for a longer period of time on the premise of maintaining normal physiological activities. The gas regulation of modified atmosphere cold storage is to reduce the oxygen concentration in the air from 2 1% to 3%~5%, that is, the fresh-keeping cold storage is based on the high-temperature cold storage, plus a set of modified atmosphere system, which uses the * * * interaction of temperature and oxygen content control to inhibit the postharvest breathing state of fruits and vegetables.
Cold storage refers to a facility that uses various equipment for refrigeration and can be artificially controlled and kept at a stable low temperature. Refrigeration system, control device, heat preservation warehouse and ancillary buildings are the basic components of cold storage.
Refrigeration emphasizes refrigeration, generally putting popsicles, ice cubes, cold meat, frozen fish and so on. Modified atmosphere storage generally emphasizes preservation, and generally puts fruits and vegetables.