The main role of vacuum packaging is to remove oxygen, so as to help prevent food spoilage, and the principle is relatively simple. The deterioration of food is mainly caused by the activity of microorganisms, and the survival of most microorganisms (such as molds and yeasts) requires oxygen. , and vacuum packaging is the use of this principle, the oxygen inside the packaging bag and food cells removed, so that microorganisms lost the living environment. Experiments show that when the oxygen concentration in the packaging bag is ≤ 1%, the growth and reproduction speed of microorganisms decreases rapidly. When the oxygen concentration is ≤ 0.5%, most microorganisms will be inhibited and stop breeding. (Note: Vacuum packaging does not inhibit the growth of anaerobic bacteria and the deterioration and discoloration of foods caused by enzymatic reactions. Therefore, it must be combined with other auxiliary methods such as cold storage, quick freezing, dehydration, high temperature sterilization, radiation sterilization, microwave sterilization, and salt. Marinated etc.)
Apart from inhibiting the growth and reproduction of microorganisms, vacuum deoxygenation is another important function to prevent food oxidation. Because oils and fats contain large amounts of unsaturated fatty acids, they are oxidized by the action of oxygen, which causes foods to taste and deteriorate. In addition, oxidation also causes Loss of vitamins A and C, unstable substances in food pigments are affected by oxygen and darken the color. Therefore, oxygen removal can effectively prevent food spoilage.
In addition to the oxygen scavenging and quality assurance functions of vacuum packaging, vacuum inflatable packaging mainly includes the functions of pressure resistance, gas barrier, and freshness preservation, and can effectively maintain the original color, fragrance, taste, shape and nutrition of foods for a long time. value.
Vacuum packaging machine
In addition, there are many foods that are not suitable for vacuum packaging and must be vacuum inflated. Such as crunchy fragile foods, easy to block foods, easily deformed to go oil foods, there are sharp corners or high hardness will pierce the bag of food. After the food is inflated and packed in vacuum, the inflation pressure in the bag is stronger than the atmospheric pressure outside the bag, which can effectively prevent the food from crushing and deforming without affecting the appearance and printing decoration of the bag.
The vacuum inflated package is filled with nitrogen, carbon dioxide, oxygen, or a single gas or a mixture of two or three gases after vacuum. Its nitrogen is an inert gas, which acts as a filling to maintain a positive pressure inside the bag to prevent air outside the bag from entering the bag and provide a protective effect on the food. Its carbon dioxide can be dissolved in various types of fats or water, leading to weak acidity of carbonic acid, and inhibiting the activity of microorganisms such as mold and spoilage bacteria. Its oxygen can inhibit the growth and reproduction of anaerobic bacteria, keep the freshness and color of fruits and vegetables, and high concentrations of oxygen can keep fresh meats bright red.