The vacuum packaging machine can automatically extract the air in the packaging bag and complete the sealing process after reaching a predetermined vacuum. It can also be filled with nitrogen or other mixed gas, and then the sealing process is completed. Vacuum packaging machines are often used in the food industry because after vacuum packaging, foods are resistant to oxidation for long-term storage.
The main function of vacuum packaging is to remove oxygen, which is beneficial to prevent food spoilage. The principle is also relatively simple, because the deterioration of food mold is mainly caused by the activity of microorganisms, and the survival of most microorganisms (such as mold and yeast) requires oxygen. Vacuum packaging is the use of this principle to remove oxygen from the inside of the bag and food cells, so that the microorganisms lose their living environment. The experiment proves that when the oxygen concentration in the package is ≤1%, the growth and reproduction speed of microorganisms will drop sharply. When the oxygen concentration is ≤0.5%, most microorganisms will be inhibited and stop breeding. (Note: Vacuum packaging can not inhibit the deterioration and discoloration of food caused by anaerobic bacteria reproduction and enzyme reaction, so it needs to be combined with other auxiliary methods, such as refrigeration, quick freezing, dehydration, high temperature sterilization, irradiation sterilization, microwave sterilization, salt Pickled, etc.)
In addition to inhibiting the growth and reproduction of microorganisms, vacuum deoxidation is another important function to prevent food oxidation. Because oils and fats contain a large amount of unsaturated fatty acids, they are oxidized by the action of oxygen, which makes foods taste and deteriorate. In addition, oxidation also makes Loss of vitamins A and C, unstable substances in food pigments are affected by oxygen, making the color darker. Therefore, oxygen scavenging can effectively prevent food from spoiling.
In addition to the deoxidation and quality assurance functions of vacuum packaging, vacuum inflated packaging mainly has the functions of anti-pressure, gas barrier and preservation, which can effectively maintain the original color, fragrance, taste, shape and nutrition of food for a long time. value.
In addition, there are many foods that are not suitable for vacuum packaging and must be vacuum-filled. Such as crispy and fragile foods, easy to agglomerate foods, easy to deform and oily foods, foods with sharp edges or high hardness will pierce the bags. After the food is vacuum-inflated and packaged, the inflation pressure in the packaging bag is stronger than the atmospheric pressure outside the packaging bag, which can effectively prevent the food from being crushed and deformed without affecting the appearance and printing decoration of the packaging bag.
The vacuum inflated package is filled with a single gas such as nitrogen, carbon dioxide or oxygen or a mixed gas of two or three gases after being vacuumed. The nitrogen gas is an inert gas, which acts as a filling to maintain a positive pressure inside the bag to prevent the air outside the bag from entering the bag, thereby protecting the food. Its carbon dioxide is soluble in various types of fat or water, and it is classified into weakly acidic carbonic acid, and has the activity of inhibiting microorganisms such as mold and spoilage bacteria. Its oxygen inhibits the growth and reproduction of anaerobic bacteria, keeps the freshness and color of fruits and vegetables, and high-concentration oxygen keeps fresh meats bright red.