In order to extend the shelf life of food, in addition to cooked food and air-dried food, most of them use cooking, sterilization, freezing and vacuum packaging, and some even add preservative additives. However, although this method can extend the shelf life, the food will easily lose its natural flavor and taste. With the rapid development of food packaging technology, applying modified atmosphere packaging machines to the preservation of food can greatly extend the shelf life of food, lock in the nutrients of food, and retain the natural flavor.
It is understood that the modified atmosphere packaging machine (MAP machine) mainly uses modified atmosphere preservation technology to replace the air in the package by using a protective mixed gas. Due to the different roles played by various protective gases, they can well inhibit the growth and reproduction of most bacteria and microorganisms that cause food spoilage, and reduce the respiration rate of products (fruits, vegetables, seafood, meat, etc.), making The food can be kept fresh, thereby extending the shelf life and shelf life of theproduct. Generally speaking, the shelf life of food is extended from 1 day to more than 8 days.
Nowadays, the application range of modified atmosphere packaging machines is becoming more and more extensive, ranging from fruits, vegetables, meat, to various braised vegetables, pickles, aquatic products, pastries, medicinal materials, etc., thus better ensuring the freshness and quality of food. Among them, as people pay more attention to the quality of meat, chilled meat has increasingly become the mainstream of meat consumption, occupying an increasing share in domestic and foreign markets. At present, by applying modified atmosphere packaging to cold fresh meat packaging, it not only ensures the freshness of cold fresh meat, but also ensures the quality and safety of the meat.
It is true that it should be noted that the key technical points in the use of modified atmosphere packaging are, first, the gasmixing ratio, and the second is gas mixing replacement. According to technical personnel, the preservation gas in controlled atmosphere preservation packaging generally consists of carbon dioxide, oxygen, nitrogen and a small amount of special gases. The gases replaced by different food materials and the gas mixing ratio are different. For example, fruits and vegetables usually replace the gas in the packaging with oxygen, carbon dioxide and other gases.
Not only that, the concentrations of different mixed gases need to be in a certain ratio, neither too high nor too low, otherwise it will not only fail to preserve the freshness of fruits and vegetables, but may also accelerate the spoilage of food. Generally speaking, the oxygen concentration ratio is 4% to 6%, and the carbon dioxide concentration ratio is 3% to 5%. If the concentration of oxygen replacement is too low, anaerobic respiration will occur, causing fermentation of lychee fruits and tissue necrosis; conversely, if the oxygen concentration is high and carbon dioxide is low, the metabolism of fruits and vegetables will decrease, shortening the shelf life.
Compared with fruits and vegetables, the modified atmosphere packaging machine used for cooked food has a much higher ratio of fresh-keeping mixed gas. For example, carbon dioxide is 34% to 36%, nitrogen is 64% to 66%, and the gas replacement rate is ≥98%. Because cooked food can easily breed bacteria and microorganisms under normal temperature conditions and accelerate spoilage and deterioration, using a modified atmosphere packaging machine to adjust the proportion of mixed gases, especially oxygen, can effectively reduce the oxygen content and slow down the reproduction rate of bacteria (anaphylactica). (except aerobic bacteria), thereby achieving the purpose of preserving the freshness of cooked food products.
In addition, when users perform gas mixing and replacement, they must fill and replace according to different ingredients. Usually, fruit and vegetable products are mainly filled with modified atmosphere packaging preservation gases consisting of O2, CO2 and N2; preservation gases for cooked food products are generally composed of CO2, N2 and other gases; while the deterioration of baked goods is mainly mildew, and preservation requires reducing oxygen, preventing mildew and maintaining flavor. , the preservation gas is composed of CO2 and N2; for fresh meat, the modified atmosphere packaging gas is composed of CO2, O2 and other gases.
However, it is worth mentioning that although the modified atmosphere packaging machine can extend the container life and shelf life of ingredients, the storage environment of different ingredients will also affect their shelf life. The shelf life of modified atmosphere packaging is determined based on the variety and freshness of the ingredients, such as strawberries, lychees, cherries, mushrooms, leafy vegetables, etc. If a low-barrier film is used, the shelf life of fruits and vegetables at 0-4℃ is 10-30 days.
For cooked food products, after modified atmosphere packaging, their shelf life is more than 5-10 days below 20℃. If the outside temperature becomes low, the shelf life is 30-60 days at 0-4℃. If the user uses a high barrier film and then uses the pasteurization process (around 80°C), the shelf life will be more than 60-90 days at room temperature. It should be noted that if modified atmosphere packaging is used combined with biological preservation technology, better preservation effects can be achieved, and the shelf life of the ingredients may be longer.
Generally speaking, modified atmosphere packaging technology has been widely used to preserve the freshness of various types of food, extend the shelf life of food, and increase the added value of food. It has great market potential in the future. However, users need to consider two key points when using modified atmosphere packaging machines. It is necessary to accurately control the mixing ratio of different gases, and fill in the corresponding modified atmosphere packaging gas according to the different ingredients, and perform gas mixing and replacement, so as to better extend the shelf life and freshness period of various ingredients.
Post time: Nov-23-2023