Food vacuum packaging puts the food into the packaging bag, extracts the air in the packaging bag, and reaches the predetermined vacuum degree, then completes the sealing process. In the food industry, vacuum packaging is very common. Various cooked products such as chicken legs, ham, sausages, grilled fish fillets, dried beef, etc.; pickled products such as various pickles and soy products, preserved fruits and other foods that need to be kept fresh Vacuum packaging is increasingly used. The fresh-keeping period of the vacuum-packed food is long, which greatly extends the shelf life of the food. Therefore, the food vacuum packaging machine has reached the degree of freshness!
The main function of food vacuum packaging is to remove oxygen, which is helpful to prevent food from spoiling. The principle is also relatively simple. The food spoilage is mainly caused by the activities of microorganisms, and most microorganisms (such as mold and yeast) need oxygen for their survival. And, vacuum packaging is to use this principle to remove the oxygen in the packaging bag and food cells, so that the microorganisms lose their living environment. Experiments show that when the oxygen concentration in the packaging bag 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 the growth of anaerobic bacteria and enzyme 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.)
In addition to inhibiting the growth and reproduction of microorganisms, another important function of vacuum deoxygenation is to prevent food oxidation. Oils and fats contain a large amount of unsaturated fatty acids, which are oxidized by the action of oxygen, causing the food to taste and deteriorate. In addition, oxidation also makes Vitamin A and C are lost, and unstable substances in food coloring are darkened by the action of oxygen. Therefore, deaeration can effectively prevent food from spoiling.
In addition to the oxygen and quality preservation functions of vacuum packaging, vacuum inflatable packaging also mainly has the functions of anti-stress, gas barrier and freshness, which can more effectively keep the original color, aroma, taste, shape and nutrition of food for a long time. value.
In addition, many foods are not suitable for vacuum packaging and must use vacuum inflatable packaging. Such as crispy and fragile foods, foods that are easy to agglomerate, foods that are easy to deform and take oil, foods with sharp edges or high hardness that will puncture the packaging bag, etc. After the food is vacuum-inflated, the inflation pressure inside the packaging bag is stronger than the atmospheric pressure outside the packaging bag, which can effectively prevent the food from being crushed and deformed under pressure and does not affect the appearance and printing decoration of the packaging bag.
The vacuum inflatable packaging is filled with a single gas such as nitrogen, carbon dioxide, oxygen or a mixture of two or three gases after vacuum. The nitrogen is an inert gas, which acts as a filling and keeps the positive pressure inside the bag to prevent the air outside the bag from entering the bag and plays a protective role for food. Its carbon dioxide can dissolve in various fats or water, lead to weak acidic carbonic acid, and has the activity of inhibiting mold, spoilage bacteria and other microorganisms. Its oxygen can inhibit the growth and reproduction of anaerobic bacteria, keep the freshness and color of fruits and vegetables, and high concentration of oxygen can keep fresh meat red.