The fresh-keeping principle of the vacuum packaging machine is not complicated, and one of the most important links is to remove the oxygen in the packaged products. As long as the oxygen in the packaging bag and food is extracted, and then the packaging is sealed to prevent air from entering, the oxidation reaction will not occur, thus achieving the effect of preservation. The use of vacuum packaging is beneficial to prevent food spoilage, because food spoilage is mainly caused by the activities of microorganisms, and most microorganisms need oxygen to survive. Vacuum packaging uses this principle to remove the oxygen in the packaging bag. Microorganisms lose their living environment. Vacuum packaging cannot inhibit the reproduction of anaerobic bacteria and the deterioration and discoloration of food caused by enzymatic reactions, so it needs to be combined with other auxiliary methods, such as refrigeration, quick freezing, dehydration, high temperature sterilization, irradiation sterilization, microwave sterilization, salt pickling, etc.
2. Prevent food oxidation
Because oily food contains a lot of unsaturated fatty acids, it will be oxidized by the action of oxygen, which will make the food taste bad and go bad. In addition, oxidation also causes the loss of vitamin A and vitamin C, and the unstable substances in food coloring are affected by oxygen, which darkens the color. Therefore, deoxygenation can effectively prevent food spoilage and maintain its color, aroma, taste and nutritional value.
The main function of vacuum inflatable packaging is not only the deoxygenation and quality preservation function of vacuum packaging, but also the functions of anti-pressure, gas blocking, and fresh-keeping, which can more effectively maintain the original color, aroma, taste, shape and nutrition of food for a long time. value. In addition, there are many foods that are not suitable for vacuum packaging, but must be vacuum inflated, such as crispy and fragile foods, foods that are easy to agglomerate, foods that are easily deformed and oily, foods with sharp edges and corners or high hardness that will pierce the packaging bags, etc. After the food is vacuum-packed, the inflation pressure inside the bag is stronger than the atmospheric pressure outside the bag, which can effectively prevent the food from being crushed and deformed under pressure, and does not affect the appearance and printing and decoration of the bag.
The vacuum inflatable packaging is filled with a single gas or mixed gas such as nitrogen, carbon dioxide, oxygen after being evacuated. Among them, nitrogen is an inert gas, which plays a filling role and maintains a positive pressure in the bag to prevent the air outside the bag from entering the bag and protect the food. Carbon dioxide can be dissolved in various fats or water to form carbonic acid with weak acidity, which can inhibit the activity of microorganisms such as mold and spoilage bacteria. Oxygen can inhibit the growth and reproduction of anaerobic bacteria, keep fruits and vegetables fresh and colorful, and high concentration of oxygen can keep fresh meat bright red.